Tag Archives: Ventilation

Twelve Foot Addition, Wall Insulation, and Purlin Settings

This Wednesday The Pole Barn Guru answers reader questions about extending an existing 60′ long pole building by twelve feet, the best way to insulate outside walls to prevent sweating, and the reasoning behind setting purlins flush with the top of the truss top chords.

DEAR POLE BARN GURU: I have an existing 40 x 60 pole building, built in the late 80’s. It has double trusses spaced 12 ft apart. I would like to extend it from 60 to 72 ft. We originally were thinking we would extend using stick frame construction but now I am wondering if this will affect the integrity of the existing building. I would like to leave the end of the pole building in place and add a door into the new space at each end. Your advice on the best way to go about this? The extension is planned for a bathroom and laundry space and would have a concrete floor. Thanks for your help. WENDY in VANCOUVER

DEAR WENDY: Adding as a post frame (pole) building will be your most economical and easiest route to go, especially as your Building Department will require engineer sealed drawings and verifying calculations. In order to determine how best to achieve your end goals, we would need detailed photos of inside and outside of your existing building, measurements at eave sides and dead center from bottom of pressure preservative treated splash plank to underside of roof steel, spacing of existing endwall columns, etc. We make deliveries into Western Washington and Northwest Oregon frequently, so freight costs will be quite reasonable. Please forward your information to Caleb@HansenPoleBuildings.com along with site address and best contact phone number.

 

DEAR POLE BARN GURU: I built a pole barn last year and am having the floor poured this week. Once completed, I will begin building an apartment inside the barn area. What is the best way to insulate the outside walls for great R value and prevent sweating? DAVID in PORTSMOUTH

DEAR DAVID: If you placed a Weather Resistant Barrier (think Tyvek or similar) between your framing and siding, then fill your insulation cavity with Rockwool and have a well sealed vapor barrier before interior finish. If no WRB, then have two or more inches of closed cell spray foam applied to inside face of your siding, then fill balance of cavity with rockwool and no interior vapor barrier. Depending upon what you do with your under slab and roof for vapor barriers and insulation, you may need to mechanically dehumidify in order to prevent condensation (sweating), as your walls alone are merely a small piece of a big puzzle.

 

DEAR POLE BARN GURU: I understand your roof design is with purlins flush with the top of the truss. Why do you use this design? Sorry if this info is on your website, I didn’t see it. Regards, STANLEY in DOSWELL

DEAR STANLEY: Here is an article on this subject: https://www.hansenpolebuildings.com/2019/02/where-oh-where-should-my-purlins-go/

Having roof purlins flush with top of trusses has many advantages:

It does not take up extra height (purlins over top of trusses either reduces interior clear height or increases eave height).

Purlins are then in perfectly straight lines, allowing for pre-drilling of roof panels (this eliminates misses). Others may try to align purlins over top of trusses using butt end splices. This makes for a very poor connection attempting to get adequate fasteners into 3/4″ (1/2 width) of truss top chords. When purlin joints are lapped, it causes a stagger of the purlins, resulting in inability to pre-drill and a significant chances of screw misses.

Purlins can be connected to trusses using engineered and Code conforming parts (in our case, quick to install Simpson Strongtie PFDB26B). Codes (as well as sound engineering practice) require purlins on edge to be solid blocked or otherwise prevented from rotation at ends. A nailed only connection would not meet this requirement).

The Shell or Interior, an Old Barn Fix, and Ventilation

Today’s Pole Barn Guru answers reader questions about inclusions of a Hansen Building Kit, some guidance with the renovation of an old barn, and how many sq inches of NFVA do foam enclosures have?

DEAR POLE BARN GURU: What does it include? Just the shell or interior also? ASHLEY in MONROE

DEAR ASHLEY: We typically provide detailed engineered plans, all verifying structural calculations, step-by-step installation instructions and materials delivered to your site for complete building shells (including doors and windows), as well as any raised wood floors and stairs. Interior stud walls (to create rooms) are usually best acquired from any nearby lumber supplier, as they are non-structural and do not support any roof or exterior wall loads. While we have provided interior wall materials, since we only send our clients very high graded lumber, it is typically not your most economical design solution.

 

DEAR POLE BARN GURU: I have an old barn, built early 1900s. A lean-to was added somewhere in the 60s. The barn is collapsing but the lean-to part is still good, size 36×24. I want to add a new posts and header for the rafters replacing the barn wall 36′ length. I plan to use wet set brackets and 6x6x16 post. I am not able to set post in the ground without removing the roof. Is 4 poles with 12′ spacing enough support? The barn, what’s left will be removed afterwards leaving an open side to put equipment in an out. DOUGLAS in TIPTON

DEAR DOUGLAS: Adequacy of those columns is going to depend entirely upon actual dimensions of your 6×6 columns, their grade and species, roof height, design wind speed and wind exposure, roof snow load, type of roofing and siding (both for weight and deflection purposes), among just a few determining factors. While what you have may very well be adequate, you should reach out to a Registered Professional Engineer to verify. Travis McDaniel of MSS Engineering is based in Indiana and would be an excellent choice to contact, as he has extensive post frame (pole barn) experience. His number is (574)855-6131.

 

vented-closure-stripDEAR POLE BARN GURU: Pole barn has metal roof with ridge vent and vented foam enclosures. How many sq inches of NFVA do foam enclosures have? TOM in ROYAL

DEAR TOM: It will depend entirely upon what brand of vented foam closures you have. We provide a Marco LP-2™ ridge vent (read more here: https://www.hansenpolebuildings.com/2014/12/ridge-vent/ with 18.4 square inches of net free ventilation per lineal foot of ridge when placed on each side of ridge, provided roof steel’s upper edges from each side are at least 1-9/16” apart.

Beam Needs, Slab Design, and Attic Ventilation Issues

This Wednesday the Pole Barn Guru answers reader questions about LVL beam procurement, a question about slab in a flood prone area, and A1V in a non vented attic.

DEAR POLE BARN GURU: I need a 3 1/4″ x 7 1/4″ x 12′ beam. Is this something you can help me with? JAMES in TUCSON

 

DEAR JAMES: While we could provide it, freight would be astronomical. Try reaching out to the ProDesk at your nearby The Home Depot.

 

DEAR POLE BARN GURU: Hello Mike, our building lot is pretty much flat. I’m using the elevation of our street at the curb as a zero reference point for our build. We are in a coastal area with occasional very minor flooding, so I would like to have the finished floor level of our radiant slab at sixteen inches above that elevation. The frost depth at this site is twenty four inches as per our building department. I’m wondering if a monolithic frost protected slab would be practical for our 56 x 48 monitor style house? I’m open to any suggestions that will allow me to use the radiant in floor heat. We’ll be requesting a design and quote soon as we still have a few more details to figure out on our floor plan. Thanks RUSS in TILGHMAN

DEAR RUSS: I always tend to error on caution’s side. I would build site up so slab was no less than 100 year (if not 1000 year) flood level. Use embedded columns with rigid insulation around perimeter down 24 inches.

 

DEAR POLE BARN GURU: Hi, I’m building a garage I was planning on heating in the winter. I was planning on drywalling and insulating the entire thing. I mounted the metal roofing directly to the purlins not using any osb sheathing, and instead opted for a metal coated bubble radiant barrier with the required droop for an air gap to control condensation. Upon completing the roof I realized that it is a non-vented attic space. Do I need to cut out all the radiant barrier and apply a closed cell spray foam to seal up the attic in order to maintain a heated space below? It has a drop ceiling FYI. Thank you, ROB in MISSOULA

DEAR ROB: Most high quality closed cell spray foam insulation applicators will only spray onto inside face of steel roofing and/or siding. This leaves you some choices: Cut out barrier, or Vent attic space and insulate directly on top of your ceiling. Personally I would likely opt for choice number two. Vented soffit panels (not every soffit panel would need to be vented in order to keep proportions proper) and vented ridge closures could be shipped to you and fiberglass or granulated rockwool insulation could be blown in on top of your ceiling. This is likely to be less expensive than closed cell spray foam and you would only need to heat area below ceiling (as opposed to also heating dead attic space above ceiling).

My New Riding Arena Has Condensation and Birds

My New Riding Arena Has Condensation and Birds

Reader BETH in LEBANON writes:

“Last fall I had an indoor riding arena built 70 x 152 x 16 that had a built in vapor barrier. The building has cathedral trusses. This is a stand alone building with no stable attached. I have had condensation in the building, especially at certain times. The floor is crushed limestone. I have experienced a bird problem and am thinking of adding a ceiling and maybe indoor panels to keep the birds out and from roosting. I also had been debating about adding insulation. Here are my questions:1. What recommendations would you have re: condensation issues when I add ceiling and maybe the indoor metal panels? 2. If I did add insulation, what type(s) do you use in this situation to provide best outcome and address condensation? I am trying to understand potential temperature impacts in extreme seasons; if it is in the 90’s outside what can I expect the differential to be inside and same with winter. I realize in winter the footing will impact potential difference due to the size of the cold floor.3. Any other comments/recommendations for this type of facility?”

Your ‘built in vapor barrier’ is most likely not a vapor barrier, but rather an Integral Condensation Control (ICC). Read more about ICCs here: https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/ 

ICCs work well when provided with adequate eave air intakes and ridge exhausts. Without these, you are likely to continue to have condensation issues, even with a ceiling installed.

Your moisture is coming up through your crushed limestone and from your horses. Ideally a heavy vapor barrier (like 15 mil) would have been placed under your limestone to prevent moisture from coming up.

Before putting in a ceiling, you will want to reach out to whoever engineered your building, to make sure you can remove those largely ineffective and possibly negatively impacting knee braces (https://www.hansenpolebuildings.com/2023/10/knee-braces-in-post-frame-buildings/). You also need to verify those trusses will even support a ceiling, as large span pole barn trusses are rarely designed for this extra weight.

In directly answering your questions:

1) Properly vent your attic space, otherwise expect long term problems

2) You need to be able to keep attic air and outside air at same temperature, could take as much as R-60. My preference would be blown in granulated rockwool, as it is unaffected by moisture, however it is heavy compared to fiberglass. Your choice will likely depend upon weight capacity of trusses.

With a steel liner panel ceiling, you may experience condensation on underside of panels, especially if you under insulate. Without an ability to heat and cool, your interior space will be close in temperature to outside – other than summer temperatures will be more like being under a shade tree.

3) In lieu of an under floor vapor barrier, make sure grade outside of building slopes away at least 10 feet in every direction by at least 5%. If you do not have gutters, get them installed, with downspouts running off again no less than 10 feet from building.

Attic Ventilation – Where Hindsight is Always 20-20

Attic Ventilation – Where Hindsight is Always 20-20

Reader CHRIS in TULSA writes:

“Hello! I have a question about attic venting that I’m just not experienced enough to answer properly. I have a new 24’x’40’x12′ post frame building I’m currently working on finishing out (fiberglass insulation, walls, ceiling, etc.). My hindsight was bad and I didn’t opt for getting an overhanging roof with soffit venting, etc. Instead I did have the builder install 2, 10′ ridge vent sections on both ends of the roof. The building will not have plumbing, but will be air conditioned with mini splits, etc. My question to you is regarding properly venting the “attic” space created once the ceiling is installed. Again, I have 2, 10′ ridge vent sections as the exhaust, but was wondering if I need to add some gable venting or something similar as the intake. I should also add the entire barn has been wrapped in Tyvek. Any help with this is greatly appreciated, or if you sell a product that would help I would be interested in more information on it. Thank you for your time!”

Sadly builders and building providers rarely take proper ventilation into consideration, leading to me getting lots of questions asked about solving later challenges.

vented-closure-stripYour ridge vents will only “work” when you have properly sized and placed air intakes. In your case, you will be limited to gable end vents. Gable vents are not nearly as effective as eave/soffit vents, so you are likely to experience poor air flow as you approach center of your building (and could have some condensation issues there as well). Tyvek would not have been my first choice in your roof, as it allows moisture to pass out and become trapped between it and your roof steel. This could potentially cause some premature degradation, over time.

At least 40% and no more than 50% of your ventilation can be located in upper portion of your attic space. You will need to know NFVA (Net Free Ventilating Area) of your ridge vents, then NFVA of your gable vents should be equal to, or slightly greater than your exhaust. Gable vents should be placed as low as possible, to achieve best airflow.

Built Without Permit, Insulation to Purlins(?), and BIBs Insulation

This week the Pole Barn Guru answers reader questions about potential issues with existing pole barn built without permit, whether or not spray foam directly to OSB is a good idea, and use of moisture barrier with BIBS insulation.

DEAR POLE BARN GURU: We are thinking about putting a purchase offer on this land in Ohio. The manufactured home burned and there is only the 40×60 pole barn left. We’re from central NY with crazy snow loads so I hoped your experience eye could take a quick look and let us know if there are glaring issues. (There was no permit filed for this building) and we’d plan to get a structural engineer if you your initial professional opinion doesn’t just say R-U-N ! LOL I’ve read your blog posts and what others have written. I like your style and knowledge !! I’ve learned more in a week from you than other places by digging a lot. Thank you for sharing your knowledge. Thanks in advance !!Deer in the headlights look, CHARY in FULTON

DEAR CHARY: Thank you for your very kind words, I do try to pass along correct answers and once in a while, be entertaining! You are smart to engage services of a Registered Professional Engineer. Pole buildings erected without permits being pulled tend to have some structural challenges – some of them (such as generally inadequate footings) are ones not visible to a naked eye. Things I would be concerned about: Diameter of footings under columns (this is a frequent builder shortcut). Is there a vapor barrier under slab? (If not, top of slab should be treated with a good sealant) Is slab perimeter insulated? (This can be retro fitted) Are columns adequately pressure preservative treated?

Wall girts may be inadequate to support applied wind loads at site Roof trusses should have bottom chord bracing no less than every 10 feet. Birds are getting into building somewhere. Best of success to you.

 

DEAR POLE BARN GURU: I am building a 24×30 pole building 15 foot wall height. I am l am planning on not putting in a ceiling and insulating directly in the purlins up to the OSB. Soffits are vented but should I put in just some small gable vents for outlet flow? MIKE in SEDRO WOOLLEY

DEAR MIKE: Insulating between purlins directly to OSB is a very bad idea and does not meet Building Code requirements. Here is an article I penned in regards to this very subject: https://www.hansenpolebuildings.com/2023/10/properly-insulating-between-roof-purlins/

 

DEAR POLE BARN GURU: I have a couple of post frame buildings 7 years old with no insulation. If I was going to use BIBs insulation does it need a vapor barrier on the outside wall? TIM in TRAVERSE CITY

DEAR TIM: I have used BIBs in a couple of my own personal buildings (read more here: https://www.hansenpolebuildings.com/2011/11/bibs/). Being fiberglass, it is negatively impacted by moisture. Ideally, you should have a weather resistant barrier (WRB) between your siding and framing/insulation. This will allow moisture to pass out of your wall cavity, but not come in from outside. If you are unable to add a WRB, you might want to consider using Rockwool batts, as they are unaffected by moisture.

High Humidity in a Pole Barn Home

High Humidity in a Pole Barn Home

Reader SAM writes: “I had a pole barn home built before pole barn homes became so popular. A concrete floor was poured around the 6×6 posts, and wooden trusses make up the roof. The pole barn walls have 2×6 purlins, and the roof has 2×4 purlins. Fiberglass insulation with a plastic vapor barrier sandwiched between the metal and the purlins. The vapor barrier is facing inside the structure, and the fiberglass is against the metal. I had living quarters framed inside the pole barn. The living structure is typical house construction with 2×4 walls, bat insulation in the walls, drywall, and cellulose blown over the ceiling joist of the living space. The living space has an HVAC with the air handler installed above the living space mounted between the trusses. When the structure was first built, the builder did not allow for any roof ventilation and no overhang or soffit vents to bring in fresh air. We started having high humidity inside the living space, even with the HVAC. Over the years, I had several HVAC companies evaluate the problem, and no one could give me an answer or solution to the problem. I removed a strip of the insulation and vapor barrier along the ridge cap and at the gable ends of the barn. I installed a vented ridge cap and used a cor-a-vent type vent installed under the gable rakes to provide ventilation up the gable walls and into the barn. I am considering installing another cor-a-vent product under the fascia along the walls to allow more airflow into the pole barn and attic space along the barn’s length. The concrete slab never appears wet on the garage side of the barn. Also, I have never noticed the flooring inside the living space being wet or damp. Do you have any ideas on why I am having the high humidity in the living space and what I can do to correct the problem?”

First why….

Everyday activities like cooking, washing, and showering can contribute to humidity levels.
Humidity levels can be affected by simple activities taking place in a household every day. These tasks can naturally add more moisture to air. Cooking and running a dishwasher can add more water vapor to kitchen air. Long, hot showers add a lot of moisture to bathrooms. Keeping areas ventilated by opening a window or installing an exhaust fan can lower humidity inside. Certain appliances, such as clothes dryers and stoves, need to vent to outside. A whole-house dehumidifier can also help eliminate some moisture created by these activities.

Leaks coming through cracks in plumbing system.
An interior plumbing leak from a bathroom or kitchen sink can cause increased moisture. Check pipes for cracks and corrosion.

Moisture from soil under your concrete slab.
If there is not a vapor barrier under your concrete slab, this can be a major source of moisture. This is called rising damp. Ineffective grading can be a significant factor since groundwater and rain can accumulate under your home. Gutters and downspouts should direct outflow at least 10 feet away from exterior walls. Ground outside your building should slope away at least six inches in 10 feet.

 

Your AC unit may be too big for your home.
Bigger isn’t always better: An oversize central AC unit may be reason for excessive moisture in a home. Evaporator coils found inside AC units act as a dehumidifier and pulls humidity from the as it runs. However, if a unit is too large, it may cool a room or home too quickly, running for only 10 to 15 minutes on a hot day before it abruptly shuts down. This is commonly referred to as short cycling. A longer runtime is needed to dehumidify a home correctly.

And then your likely solution:
I am surprised none of your HVAC professionals have recommended an ERV (Energy Recovery Ventilator). An ERV system will keep your indoor relative humidity at a desirable level.

Air Intake, Sliding Door Trolleys, and Footing Costs

This Thursday is another bonus ” ask the Guru” answering questions about proper air intake with no overhangs, replacing sliding door trolleys, and most cost effective footing solution.

DEAR POLE BARN GURU: I am in preliminary stages of designing a post-frame building, that will serve a multitude of functions such as a home gym, work-shop, and area to host family parties. It is a 30′ x 76′ x 20′ tall, with 2 fully enclosed leans 64′ long on each side that span out 16′. I really like Scandinavian style, which utilizes no overhang. My main concern is how to allow for proper air intake if I do zero over-hang since there will not any soffit. Curious for your thoughts. Would you recommend against ‘zero over-hang’? Or do you think there is some work-around for air intake and gutter attachment? Hoping for a quick answer! Thanks in advance : ) SHANE in HARTLAND

DEAR SHANE: In my humble opinion – I would personally go without doors, before I would go without overhangs. For me it is about looks (no overhangs look too industrial for my tastes), functionality (besides being a perfect location for air intake, they do keep your walls much cleaner, provide protection of windows from summer sun, pushes rainfall/snow away from base of building). You can meet Code requirements for air intake via gable vents, however they do not afford nearly as even airflow as to eave intake vents combined with a vented ridge. Gutters can be hung off from eave struts (aka eave girt or eave purlin), however it does increase possibilities of having water back up into one’s wall if an ice dam were to occur.

 

DEAR POLE BARN GURU: I have a quonset with (2) 15’x14′ sliding doors with 4 cannonball style rollers each that need to be replaced. I’m thinking I’ll have to remove the doors, but what is the best way to do this? CODY in MAYNARD

DEAR CODY: If these are one piece doors and not bi-parting, you can remove any end stops and slide door out of rail on one end, replace trolley, then repeat in opposite direction. If doors are bi-parting, you will need to remove doors to replace trolleys (and have plenty of help, as doors will be unwieldy).

 

DEAR POLE BARN GURU: I been debating on what foundation to go with. I’m in Texas 1.5 hours west of Houston. I noticed some going with piers and slab or the wall footing with slab. It’s going to be a post frame house. Possibly shingle roof. What is the best foundation system that will not fail? ANGEL in SEALY

Pole FootingDEAR ANGEL: Your strongest and most affordable foundation will be to use true glulaminated columns, embedded in ground. Regardless of what you pick, it will only be as good as ground it is placed upon. A well prepared site, where clays and organic materials have been removed and proper fill has been placed and compacted every six inches, will greatly improve your chances of having a solid foundation. I would encourage you to consider a steel roof, as shingles have a very short life span (read more here: https://www.hansenpolebuildings.com/2018/10/ask-the-builder/.

Will I Have Issues With Post Frame Closed Cell Spray Foam Insulation?

Will I Have Issues With Post Frame Closed Cell Spray Foam Insulation?

Reader HEATH in NACOGDOCHES writes:

“I am building a pole barn that I do not plan to heat or cool initially, but would like to insulate due to condensation issues and our hot humid climate. Have there been issues with closed cell spf in post frame buildings. My main concern would be if there ever was a screw to back out and cause a leak. Probably overthinking it, but just trying to make a decision on what makes most sense. I am also open to soffit vents and installing a ceiling and blowing in insulation.”

Screws do not “back out”. Watch a screw being driven in – it pulls the wood fibers up. Wood has an inherent “memory” and as those disturbed fibers return to their natural state, they want to pull screws in (creating even a tighter seal).

Screw leaks are caused by either poor installation, wrong placement (on high ribs rather than flats), or entirely wrong parts. Poor installation will show up right away – either in a good rain storm, or by checking weather tightness by running a water hose on roof. I would recommend second of these prior to any interior finishes.

 

Most of our industry uses #9 or #10 diameter screws and often only an inch long. We found, under even a small load, one inch screws will pull out of lumber – so use 1-1/2″ screws. Next issue is one of time. Eventually slots will form around shanks of #9 or #10 screws, due to cyclic loading from wind. One these slots get long enough, they extend past screw’s washers and you have a leak. We use on larger diameter screw shank diaphragm screws to eliminate this as a challenge. Many are also using screws with neoprene rubber gaskets. These are not UV resistant and will break down due to sunlight. When this occurs, you again have leaks. There is an easy solution – EPDM gaskets. Yes, they cost a bit more, however damage from a single leak outweighs any up-front costs.

If you opt for closed cell spray foam, you want to have it applied directly to inside of steel panels, with no other barrier between insulation and siding or roofing. You will need to mechanically dehumidify, as your building envelope will be air tight. Given your climate, this would be my personal choice.

An alternative would be to blow in insulation over a ceiling. You should then order raised heel trusses to attain full insulation depth from wall-to-wall. Vent eaves and ridge in correct proportions and order roof steel with an Integral Condensation Control factory applied, to avoid having drips in your dead attic space.

Florida Approved Wall Panels, Drip Stop Metal Roofing, and Widest Builds

This week the Pole Barn Guru discusses reader concerns about Florida approved board and batten panels for walls, the use of drip stop or condenstop in residential applications, and what the widest build without support poles could be.

Close up image of Florida on a map with a pin over Tampa.DEAR POLE BARN GURU: I need a 4×8 siding material that has a Florida Product Approval Code. I was hoping to use Georgia-Pacific Plytanium T1-11, but it does not seem to be approved. What would you suggest for a board-and-batten siding that is approved? The barn is 30×48, 14′ side walls. CHRIS in ORLANDO

DEAR CHRIS: Plytanium is not a structural panel, however it could be applied as siding over an approved OSB or plywood sheathing.

JamesHardie Cempanel siding (as an example) has a Florida approval (FL13223). You can stop at your local The Home Depot ProDesk and inquire as to what other readily available options would have Florida approvals.

 

DEAR POLE BARN GURU: Hello, my name is Martin and I am a local building inspector here in Ohio. I do residential and commercial building inspections. I recently inspected a newly built home that had Drip Stop metal installed on the roof. It was installed on 2×4 trusses 2’ on center with pine 2×4 purlins. This new build home has NO plywood or moisture barrier other than the metal drip stop roof. This is a fairly new product. I am a little confused on the proper application procedures for a residential home. Your product is wonderful and it is really catching on here in Ohio, I have it installed on my 1976 residential home, but it was installed right over the existing fiberglass shingles with wood purlins. So with that said can you send me any drawings or application procedures your company recommends for new residential home construction and also anything you recommend for installing the drip stop over an existing fiberglass shingle. Feel free to call my business cell to help explain and walk me through the process. I appreciate your time and any installation procedures your team would recommend. MARTIN in OHIO

DEAR MARTIN: Thank you for reaching out to us. Integral Condensation Controls (Dripstop, Condenstop, etc.) are wonderful products. In order to properly function, they do require proper airflow (vented eave soffits and vented ridge, in correct proportions). Installing over a roof deck (either new construction or a reroof) does defeat purpose of preventing condensation (any warm moist air from attic is prevented from contacting underside of cooler roof steel already), however it would still have benefits of reduced sound transmission and decrease in solar heat gain.

 

DEAR POLE BARN GURU: Is it cheaper to build wider rather than longer? How wide can be built without support beams? KRIS in VEEDERSBURG

DEAR KRIS: Ultimately, your most effective interior layout should override saving or spending a few extra cents per square foot. While perfectly square, is typically going to be more cost effective (due to having less wall surface), as long as your length to width ratio is under 3:1 it normally is not going to significantly impact your costs (provided you are not in an extreme wind area, or excessively tall). While I have built clearspan post frame to 100 feet in width (and had engineered designs of 140 feet), price per square foot generally starts to ramp up beyond 80 foot wide. This will, of course, depend upon applicable roof loads.

Challenges to Insulating an Existing Pole Building

Challenges to Insulating an Existing Pole Building

Reader TODD in STACY writes:

“Hello, I am looking to insulate and heat an existing 30x40x12 pole building that was built in the mid 2000’s. It does not have soffits or ridge vents. The way it is now it gets condensation on the inside quite often just with daily weather, I assume because of the lack of ventilation. I am planning on steel liner panel ceiling, poly vaper barrier and blown in fiberglass. But the problem is how do I achieve adequate ventilation without soffits? I am worried that once i get all the insulation in and still have condensation problems and end up with wet insulation. Also, last spring, as ALL the snow from last winter was melting the water was making it up and under the roof overlaps and was freezing and spreading them open and dripping inside! Would having it insulated have kept this from happening? I couldn’t help but think it was a good thing I didn’t have it insulated then or my insulation would of been soaked! But I thought maybe it wouldn’t of happened if it had been insulated, what are your thoughts on that? When it comes the wall insulation some say to wrap everything with a house wrap from the inside, insulate with fiberglass and then poly vaper barrier and then the steel liner panel. Others say the house wrap isn’t necessary just the inside poly. What do you recommend? Thank you for your help!”

It sounds like your building has several things going on, some of them easily fixable.

If your building does not have an under-slab vapor barrier – seal it. This is your top source of moisture inside of buildings. Think of concrete as a sponge rather than a solid (concrete being actually relatively porous). Pores in concrete (smaller than human hairs. so invisible to a naked eye) constitute 12 to 18% or more of a concrete slab!

Water coming through roof steel laps…this will normally only occur if steel has been overlapped incorrectly. Smaller, or partial, rib should go over top of larger full rib. This occurs all too often, even when supposedly professional builders are hired. If this is your case, it can be remedied – remove ridge caps (number them, so they get put back in same order they came off), then remove screws closest to laps. Pull up on edge of panel currently on top. While it is being held up, pull up on other panel edge, then put full lap edge down, overlapping it with partial lap. Use screws one size large diameter and 1/2″ greater in length to refasten steel panels.

vented-closure-stripWhile ridge cap is off, replace solid foam closure strips with vented ones. Use 1-1/4″ long #12 stitch (metal-to-metal) screws to reattach ridge caps.

Add gable vents for air intake, bottom edge of vents should be just above thickness of ceiling insulation you will be adding. You will need to add 144 square inches of NFVA (Net Free Ventilating Area) at each end.

I am guessing your roof steel has no means of controlling condensation currently. Your easiest solve, at this point, is to have two inches of closed cell spray foam applied directly to underside of roof steel. Otherwise, you could remove entire roof and install a thermal break. Some possibilities would be reflective radiant barrier (with seams taped), metal building insulation (with seams overlapped and stapled together), or solid sheathing (such as plywood or OSB) with 30# felt applied over top.

If you can obtain it, consider blowing in granulated rockwool, rather than fiberglass, as it is not affected by moisture.

Walls – while housewrap would have been nice, rather than pulling off all wall steel, I would use rockwool batts to entirely fill cavity, well-sealed interior vapor barrier, then your steel liner panels.

Attic Ventilation, Shearwall Stitch Screws, and Adding Sheathing

This week the Pole Barn Guru addresses reader questions about ventilation needed for a new attic with metal ceiling and blown-in insulation, a confirmation for endwall needing stitch screws for shear, and if adding sheathing to an existing pole building would add value.

DEAR POLE BARN GURU: I bought a house with a pole barn that is unfinished inside. The metal walls were not wrapped and the only insulation in the barn whatsoever is double bubble on the underside of the barn roof. I am going to have a metal ceiling put in and then blown fiberglass insulation for an R30 value in what will then be the attic. There is currently no ridge vent nor gable vents either so I am concerned about air flow in the attic once the metal ceiling and blown insulation are complete. The eaves have perforated soffit so I’m hoping even after the blown insulation is done that will provide an air flow into the attic. So am I correct to think that I need to have gable vents put at each end or a ridge vent so that there is positive air flow through the attic? Thanks! BILL in STEVENSVILLE

DEAR BILL: Your thinking is absolutely correct – you need an adequate ventilation exhaust point. Ideally, this would be at your ridge. Gable vents, while meeting code requirements, actually only provide good ventilation immediately closest to vent locations.

This article covers requirements for attic ventilation: https://www.hansenpolebuildings.com/2023/06/274512/

In Queen Anne’s County – you are in Climate Zone 4A. 2021’s IECC (International Energy Conservation Code) specifies R-60 for ceilings in your climate zone. As so much of your cost of blown insulation is having installers show up, you may want to consider going with a greater R value than originally planned. Energy costs are not ever going to go down (nor cost of insulating).

 

DEAR POLE BARN GURU: I have a rear end wall that is labeled shear wall that says I need an inch and a quarter number 12. Stitch screw 9 and 3/8 on center. Is that every 9 and 3/8 on center vertically on each overlap? DAMINA in TONOPAH

DEAR DAMIAN: You are correct. Panels stitched together have roughly twice as much shear capacity as do unstitched panels.

 

DEAR POLE BARN GURU: Question for you Guru! I bought a property with a small pole building/shed. Is there any value in adding sheathing? If so, how do you retroactively figure out if the roof will handle the additional load? JESSE

DEAR JESSE: If the roof steel is properly fastened (1-1/2″ screws in flats along one side of each high rib in field, #12 or #14 x 1-1/2″ screws both sides of each high rib at eave and ridge) chances are it will perform admirably without any sheathing. Think of steel roofing and siding as acting like very strong, very thin OSB or plywood.

 

What to do About Possible Roof Condensation?

What to do About Possible Roof Condensation?

Reader JEFF in ADEL writes:

“Hello, I am going to order Post Frame building materials and am working on details. The question about condensation is driving me nuts as this is a big project for me and I don’t want a wet building. It will be a 30x48x11 high side walls. 8′ on center truss/posts. No overhangs on any side Concrete floor. Not heated, not insulated and not finished inside. Location in central Iowa, I plan to wrap the walls with house wrap during build, to block wind and rain. What do I do for the roof? My worry is condensation. I have 2 neighbors that have somewhat similar builds that did nothing and say they don’t have condensation problems. My vendor offers house wrap, or a radiant barrier. What I have read says don’t use house wrap on roof because it is not a vapor barrier. I agree with that assessment. My vendor does not offer a dripstop backed steel. This condensation problem seems baffling as there is so much conflicting information and everyone you ask has a bias to sell something that may or may not work and might deteriorate and might make it worse. Am I over thinking it and should I just put up the building and fix the problem later only if I have it? Or is there a simple solution? Thank you.”

Thank you for reaching out to me. All I can say is, your neighbors have been lucky.

To begin with, I would recommend you build a fully engineered building utilizing double trusses every 12 feet rather than single trusses every eight feet.

Why?

Worst part of any building is digging holes, fewer holes means less probability of hitting a Volkswagon sized rock.

Every 12 feet, means fewer columns to set (posts are not your building’s weak link), fewer connections to be made and less pieces to handle, making for a quicker installation.

Double trusses reduce needed truss bracing, as well as creating actual physical load sharing between these two members. In event of a catastrophic snow even, likelihood of both trusses having an exact same weak point and failing is about as close to zero as one can get.

Moving forward – consider adding enclosed vented overhangs on your sidewalls (if not enclosed overhangs on all four sides). You only get a single opportunity to have overhangs. Personally, I would do without doors before I would do without overhangs. You can always add doors later, but not overhangs. Overhangs will keep your building walls cleaner, as they push rain runoff and snow slide off away from your building walls. Your building will look less industrial (better for resale) and it affords an air intake for ventilation.

Combined with a vented ridge, Hansen Pole Buildings can also provide roof steel with a factory applied Integral Condensation Control. This should eliminate all possible future roof

condensation concerns.

Extended reading on Integral Condensation Controls here: https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/

As you have deduced housewrap is wrong product under roof steel for condensation control. It does not create a thermal break – so now condensation appears on bottom of wrap, or moisture passes through and is trapped between roof steel and barrier. Radiant barriers can work – provided all seams are completely sealed. There have been issues with some brands delaminating or facing flaking off over time. This, and difficulty installing in general, are why we stopped offering them several years ago. If you build now, ignoring possible challenges, and they occur – your only practical fix is two inches of closed cell spray foam insulation applied directly to underside of roof steel. We are also finding, other than pure animal confinement structures, most post frame buildings are being insulated at some future date. It is only prudent to take steps to have appropriate ventilation, should someone later decide insulation to be a good idea.

Help! Help! PEMB Insulation/Ventilation

Help! Help! PEMB Insulation/Ventilation

Reader JD in ANDERSON writes:

“Dear Guru, I am finally ready to build my dream shop, rec space. Slab is poured. Will be 30x50x16 with (2) insulated panel 12×14 overhead doors in one of the 30ft ends. My question is about ventilation / insulation. To meet my budget, I chose a cold formed steel framed building with vertical 24 gauge steel roof & siding. I want the building to be “livable” & plan to install (2) mini split heat pumps for heating & cooling. I’m in southern SC so no real extreme temps. The building co wants to insulate with Prodex sandwiched between the siding & frame. There is no finished ceiling or attic space & there is a ridge vent from end to end. When asked about how to keep heat in during the winter due to the ridge vent, they tell me “that’s not something we worry about”. Not sure what that means but I assume heat rises & will vent out the ridge making it impossible to heat. Down the rabbit hole I went. First thing I found was everyone bashing Prodex. Ok, I figure the majority of steel buildings have been insulated with faced fiberglass batt since the beginning of time, I’ll do that. Then I read about moisture & mold caused by the batt. Ok, spray foam then, perfect! Then I’m told it voids the building warranty. My head hurts! I have just about decided to spray foam anyway with 2in of close cell on the walls & the roof. But what about ventilation? The spray foam folks say that with their product there is no need to ventilation in the building at all. They say no need for the ridge vent & the closed cell will be sprayed right over it to seal it off. If I don’t use the Prodex, the building co says there will be no heat transfer break between the siding & framing. Siding will be screwed straight to metal frames. There will also be no radiant reflective barrier or vapor barrier. The spray foam place says I don’t need either. They say the miraculous closed cell foam will handle it all. Basically they are telling me that the inside of my building will be a huge styrofoam beer cooler & will need no ventilation to control moisture & there will be no heat transfer at all. This is a HUGE investment & I can only do it once. It has to be right the first time. Please help!!!! Thanks so very much!!!”

There is sadly so much bad information available.

Prodex (or any other reflective radiant barrier) is not insulation. If properly sealed, it can be an effective vapor barrier. If you use it and vent ridge, then you are correct – out ridge goes your heat.

Fiberglass is not a cause of mold and mildew, it is a symptom of a building without adequate methods of removing excess moisture.

Closed cell spray foam – ask to see a written warranty copy showing building or even steel cladding with closed cell spray foam applied will void it. Chances are very small one exists.

What would I do?

Closed cell spray foam at least two inches thick sprayed directly on inside of steel roofing and siding. No ridge vent. Have a qualified HVAC provider design a system to mechanically remove excess humidity. You will need to fire protect inside face of closed cell spray foam. This might be an option https://www.hansenpolebuildings.com/2019/08/fire-rated-spray-foam-insulation/. Intumescent paint may also be a possibility. If you want higher than R-14, you could go with thicker closed cell, add open cell to inside face of closed cell, or add unfaced batts (my preference would be rockwool)

Attic Ventilation With Trusscore Wall and Ceiling Panels

Attic Ventilation With Trusscore Wall and Ceiling Panels

Reader STACY in NEW BERG wrties:

“Hi, I have a pole building 28’x48′ 16′ high eave height. It’s used as a shop and RV storage. I’m insulating it and planning on heating it with a pellet stove. I’ve read your posts in many instances about (NOT) using a vapor barrier in the ceiling. Ok, that’s great, less work. However, I’m planning on using a fairly new product by Trusscore, wall and ceiling panels. These are a PVC material and can possibly be viewed as a vapor barrier itself, they lock-in tight to each other. The shop roof is 1/2″ Plywood and Tiger paw vapor barrier under 26 gauge Standing seam metal roof. I have a Gable vent powered with an Attic fan programmable by temp and/or humidity. I guess my question is, since I should not be putting up a vapor barrier, and given this material I’m using for the ceiling, should I be adding any venting through the ceiling to allow warm moist air from the shop to pass through the attic space? Seems like that would be wasting heat but, the moisture needs to go somewhere, right? Thanks much.”

Trusscore came about in 2020, as an alternative to painted drywall. It is a ½” thick panel with an unique internal truss design combined with high-strength polymer formulation.

Polyvinyl chloride (PVC) is an exceptionally durable material. It has a service life of up to 100 years and can stand up to wear and tear coming with interior wall and ceiling panels in residential, commercial, and agricultural applications.

Scratch, dent, and damage resistance properties make Trusscore Wall and Ceiling Board a great drywall alternative.

Combining PVC material and an internal truss design, you have durable, impact-resistant wall and ceiling panels able to stand up to contact without showing dents, cracks, or damage.

Trusscore products can handle nearly anything being thrown at them. From high-traffic residential spaces, commercial kitchens, to barns and workshops. I will guess you are also insulating at ceiling level, directly above your PVC Panels. You are creating a building “drying to inside” meaning it will be necessary to mechanically dehumidify (reach out to a qualified HVAC provider), otherwise you will have serious condensation problems. I am also concerned about your attic ventilation – as unconditioned dead attic spaces require both air intake and exhausts, in correct proportion. Not following these requirements will likely result in premature degradation of your roof system, or at least mold issues. You can read more on ventilation requirements here: https://www.hansenpolebuildings.com/2023/06/274512/

*For those of you who are wondering, Trusscore is not necessarily for those who are faint of pocketbook. Expect to pay somewhere around four dollars per square foot for panels only – roughly 10 times cost of gypsum wallboard (sheetrock).

2018 IRC Attic Ventilation Requirements

2018 IRC Attic Ventilation Requirements

Reader SCOTT in MINNESOTA writes:

“I read a couple of articles on your website and was hoping you could answer a question or give me some insight on venting my shop building,

It is pole barn construction with 24” vented soffits and a ridge vent.   The original foam/screen closures on the ridge vent were along the entire length of the ridge but over the years have pretty much deteriorated and come down in pieces.  This last Minnesota winter was hard on them.  I think replacing them with an “LP2 like” option available from Midwest Manufacturing will be a good idea and probably last longer than the simple 1” wide foam style.   My building is 40’ x 40’ with a 42’ ridge and it is finished inside with a level ceiling.

Questions:

Should I do the entire length of the ridge with vented closures or do I just need a percentage? 

If I don’t do the entire length should the sections of venting match on both sides of the ridge?  

Any thoughts on this matter would be appreciated.

Thanks for your time.”

Mike the Pole Barn Guru says:

Historically, IRC (International Residential Code) ventilation requirements are applicable to one and two family homes and have been based on a ratio of “net free ventilating area” (NFVA) being area of ventilation openings in attic to area of attic space. NFVA is the total unobstructed area air can pass through and it is calculated at the most restricted location through a vent’s cross section.


Ventilation requirements listed in Section R806 in IRC’s 2018 edition are listed in excerpts below:

  • R806.1 Ventilation Required. Enclosed attic and enclosed rafter spaces formed where ceilings are applied directly to the underside of the roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow. Ventilation openings shall have a least dimension of 1/16 inch minimum and ¼ inch maximum. Ventilation openings having a least dimension larger than ¼ inch shall be provided with corrosion-resistant wire cloth screening, hardware cloth, perforated vinyl or similar material with openings having a least dimension of 1/16 inch minimum and ¼ inch maximum. Openings in roof framing members shall conform to the requirements of Section R802.7. Required ventilation openings shall open directly to the outside air and shall be protected to prevent the entry of birds, rodents, snakes and other similar creatures.

  • R806.2 Minimum Vent Area. The minimum net free ventilating area shall be 1/150 of the area of the vented space.  Exception: The minimum net free ventilating area shall be 1/300 of the vented space provided both of the following conditions are met:

  1. In climate zones 6, 7 and 8, a Class I or II vapor retarder is installed on the warm-in-winter side of the ceiling.

  2. At least 40 percent and not more than 50 percent of the required ventilating area is provided by the ventilators located in the upper portion of the attic or rafter space. Upper ventilators shall be located no more than 3 feet below the ridge or highest point of the space, measured vertically. The balance of the required ventilation provided shall be located in the bottom one-third of the attic space. Where the location of wall or roof framing members conflicts with the installation of upper ventilators, installation more than 3 feet below the ridge or highest point of the space shall be permitted.

  • R806.3 Vent and Insulation Clearance. Where eave or cornice vents are installed, blocking, bridging and insulation shall not block the free flow of air. Not less than a 1-inch space shall be provided between the insulation and the roof sheathing and at the location of the vent.

  • R806.4 Installation and Weather Protection. Ventilators shall be installed in accordance with manufacturer’s installation instructions. Installation of ventilators in roof systems shall be in accordance with the requirements of Section R903.

In summary,  ventilation requirements in IRC’s 2018 edition are:


  • Provision of 1 square foot of NFVA for each 150 square feet of attic floor. One important note – attic floor area is just as it reads – area – not volume. This is a minimum requirement and does not stipulate  required ventilation openings provide intake (low), exhaust (high), or both.
    • Provision of 1 square foot of NFVA for each 300 square feet of attic floor if both following conditions are applicable:
    • A Class 1 (≤ 0.1 Perm) or 2 (> 0.1 to ≤ 1.0 Perm) vapor retarder is installed on warm-in-winter side of ceiling when the structure is located in climate zone 6, 7, or 8.
    • At least 40%, but not more than 50% of NFVA is provided by vents located not more than 3 feet below roof’s highest point.
    • Provision for a minimum 1 inch air space between roof sheathing and insulation in attic at vent location.

Hopefully this Code lingo didn’t dull your senses too badly!

A Marco LP-2™ ridge vent (read more here: https://www.hansenpolebuildings.com/2014/12/ridge-vent/ provides 18.4 square inches of net free ventilation per lineal foot of ridge when placed on each side of ridge, provided roof steel’s upper edges from each side are at least 1-9/16” apart.

As a maximum of 50% of required ventilation can be at ridge, 18.4 X 2 X 300 / 144 = 76’8” as maximum building width these vents can handle on a gabled roof.

You will need to determine NFVA of your vented soffits in order to calculate the correct ratio of intake to exhaust. If the entire ridge does not have to be vented, it would be prudent to have equal footage of vented closures on each side of the ridge.

Dead Air as an Insulator

Dead Air as an Insulator

Are you considering building a climate controlled post-frame building? If so, then proper insulation is (or should be) at the top of your list.

Reflective InsulationIf you have not seen ridiculous claims of double digit R-values from reflective radiant barriers yet (aka ‘bubble wrap insulation”) you will. Read more about these claims here: https://www.hansenpolebuildings.com/2014/04/reflective-insulation-wars/

Reflective radiant barrier manufacturers base their R-value claims upon an assembly including a 100% sealed dead air space on one or both sides of their products. In all reality, it is impossible to achieve this in real world construction.

For many years buildings have been built with an air space between building cladding and batt insulation in wall cavities. This air space did, in fact, help circulate air inside the wall and ventilate humidity through the wall. Now, as we increase wall air tightness quality and increase insulation levels, this air space no longer serves a ventilating function. Being on modern heavy insulation outside, it is too cold to help much with ventilation, and convection currents in this air space can actually make condensation problems worse. In addition, this air space is not a very good insulator. It is now recommended that all space between inside wall finishes (such as gypsum wall board) and outside cladding be filled with insulation, leaving no air space. Again – when insulating an exterior wall, don’t leave any air space.

Improper installation techniques with batt insulation can cost you 20% of an exterior wall’s insulating value from air spaces in hidden corners. This radically increases thermal bridging through framing members.  If, on these same walls, you have an accidental space between insulation and vapor barrier, an air current can loop around insulation taking heat directly from warm interior finishes to cold cladding.

For an air space between wall insulation and interior finishes, vapor barrier location is critical.  If an air space is between insulation and vapor barrier, air will rise because of building warmth.  This air movement will find its way through or around insulation to cold side, where it will fall due to cladding’s colder surface.  When insulation completely fills space between wall girts this looping is minimal.  When insulation is installed less than perfectly, this looping force will accelerate.  If there are open triangular corner spaces as mentioned above, this becomes a pump moving heat from interior finish to cladding as if there was no insulation there at all. 

When there is an air space between vapor barrier and interior finish, nothing happens.  Temperature goes from cool on bottom to warm on top but air in this space has no access to cold exterior cladding.  It may circulate but it has no more effect than room air circulation. 

Years ago walls were constructed to leave an air space between exterior wall framing and interior finishes.  This was enough thermal break to stop condensation from forming on interior finishes in line with wall girts.  With modern construction and heavier insulation, there is no longer a condensation problem on interior finishes caused by girts being cold.  (There still is heat loss and in some climate zones building codes now actually require sheet insulation over all wall girts, either inside, or outside.)  An air space’s insulating value is very small compared to the same thickness of any insulation. 

Trapped air is an excellent insulator. Air moving freely carries heat. Circulating air, such as in a wall cavity, is effective at pumping heat from warm side to cold side. Not an insulator, in other words.

To be effective at isolating heat, air must be confined, trapped in tiny spaces, like in fibers of fiberglass, rock wool, or cellulose. Foam is particularly good at trapping air. So you take a not a very good heat conductor product and arrange for it to have many tiny cells able to capture air.

Financing, Ventilation for Metal Trussed Shed, and Concrete Costs

This week the Pole Barn Guru answers reader questions about what financing is available for a post frame building, a question about ventilation for a metal trusses pole barn, and a comparison of concrete costs for post frame vs red iron buildings.

MoneyDEAR POLE BARN GURU: I’m looking to build a 25′ x 50′ pole barn 16 ft with an open lean-to on each side. I’d like the lean-to’s to be 20′ wide and the same depth (50′).so the total width would be 65′ by 50′ deep. My question is about financing. I’m not sure how financing would work. Do you have a financing co. or if that something I would get on my side? Thanks SHANE in BRIDGETON

DEAR SHANE: Financing is actually quite simple. Here is link to apply: https://www.hansenpolebuildings.com/financing/

 

DEAR POLE BARN GURU: I am looking at building a 30×50 pole barn with metal trusses.  There is no soffit. I will be adding central hvac unit. Will stud up the walls between posts and add faced fiberglass Batts. Ceiling will be kept vaulted with metal on underside. Question is what insulation should I go with in the ceiling and will I have issues with not having a soffit or any roof venting? CHRIS in COLUMBIA

DEAR CHRIS: If you are insulating directly above bottom of trusses, then you need to ventilate this dead attic space. You could use rectangular gable vents spaced along each sidewall and have a vented ridge.

https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/
I would recommend blowing in granulated Rockwool, as it has a high R-value to thickness and is unaffected by moisture. You are in Climate Zone 3, so you should have at least a R-49 in your ceiling.

 

DEAR POLE BARN GURU:  I am looking into your building system and I wanted to compare the general concrete amount and cost.  Would you say that a pole barn uses less concrete than a red iron/tube steel building?  If so, how much generally speaking and what details can you provide. BRONSON

Screeding ConcreteDEAR BRONSON: Thank you for your interest in a new Hansen Pole Building.

Tube steel buildings are generally not considered to be permanent structures, so generally use very little concrete (and usually cannot be permitted, as they are not permanent).

Red Iron (Pre-engineered Metal Buildings) usually require you to hire an independent foundation engineer. As PEMBs have a significant outward force at base of frame verticals, they most often have a significantly large pier at each column (and require precision placed anchor bolts). Actual dimensions will vary greatly due to dimensions of building, roof slope, soil conditions and if there is a concrete slab on grade or not. It is not uncommon for single piers to take a yard or more of concrete.

Obviously many aspects come into play in determination of post frame building column concrete. Other than miscellaneous door columns, it would not be unusual for a 40′ x 60′ post frame building (as an example) to need under three yards of concrete for all column footings. Post frame slabs on grade do not require thickened edges – so a nominal four inch slab 40′ x 60′ would take 30 yards of premix.

 

 

 

Knee Bracing, Flying Gable Trim, and Ventilation Needs

This week the Pole Barn Guru answers reader questions about the removal of knee bracing to install interior ceiling and wall steel, a question about a special rake trim for a flying gable, and the possibility of adding ceiling liner panels to a structure and the need for a vapor barrier and proper ventilation.

Pole Barn Knee BracesDEAR POLE BARN GURU: Can I remove my knee bracing from the pole barn and put up interior ceiling and wall steel. I have a 60×104 pole barn on an 8″ wide 4′ high concrete wall with wet set braces (6×6 laminated beams. 8′ on center) ceiling is 16′ from floor my knee bracing takes up too much wall storage space. They brought them too far down the wall. About 6′. SEAN in MONTPELIER

DEAR SEAN: While knee braces generally cause far more structural harm, than good, they should never be removed without written authorization from whomever your building’s engineer is. If your building was not engineered (hopefully it was), then you should at least request written authorization from your provider including verification their removal will not affect any structural warranty.

In this article, another person dealt with similar issues: https://www.hansenpolebuildings.com/2015/11/can-i-take-out-knee-braces/

 

DEAR POLE BARN GURU: How do I trim out a metal ribbed roof panel on a barn with a widows peak? How do I make it match up with the rake trim? While maintaining proper drainage. KEVIN in LINCOLN

DEAR KEVIN: Your building kit provider should have had delivered to you one or more ‘special’ rake trims (one long side like a standard rake/corner trim, other flat with a hem) and some Emseal expanding closures. Here are your installation instructions: https://www.hansenpolebuildings.com/2016/05/9-steps-constructing-widows-peak/

 

DEAR POLE BARN GURU: I have a pole barn with a scissor truss (interior sloped ceiling) at 8′ on center. The builder placed insulation between the trusses and are kept from sagging by perpendicular metal straps approximately 2′ apart. When the breeze blows into the shop, the insulation batts float up and down like waves. I was thinking of installing a metal ceiling. I am concerned about the 8′ span between trusses and the possible need for a vapor barrier. What do you recommend? GREG in HUDSON

vented-closure-stripDEAR GREG: Hopefully you have vented eave soffits and ridge cap in correct ratios as lack of ventilation or too much or too little in wrong places can cause challenges (please read more here: https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/).

In your Climate Zone a ceiling vapor barrier should prove unnecessary. While I would not span eight feet with ceiling liner panels, I do see it being done successfully by many builders and specifiers.

 

Condensation Control, Ventilation or Insulation

Most Builders Do Not Understand Condensation Control, Ventilation or Insulation

Crucial to proper performance of climate controlled buildings of any sort is condensation control, adequate ventilation and insulation. Sadly, most builders do not understand how to come up with a proper design solution.

Reader AARON in WISCONSIN DELLS writes:

“Hello, I was wondering if you had a minute for a quick question ? I have read posts for countless hours regarding vapor barrier between trusses and roof steel and I can’t find the answer I’m looking for. I’m building a 44×96 that will have in floor heat in South central Wisconsin (by Madison) so we have cold winters and humid summers. Walls will be spray foamed. I will be applying a vapor barrier (poly) to the bottom of roof trusses and then putting a metal ceiling on and spraying fiberglass insulation above the ceiling. Fully vented ridge cap and 2’ overhangs with vented soffits around the entire building. The builder did not put any vapor barrier down between the roof steel and the trusses so the steel is directly on the trusses. Could this end up creating a moisture issue or will I have enough air flow in the attic space that I do not need the vapor barrier between the roof metal and trusses ? Thank you very much for your time.”

Thank you for reaching out to me Aaron, I am always available to answer questions.

Your builder sadly did you no favors in not having a means to prevent condensation on your roof steel underside. It also requires having an actual thermal break, not just a vapor barrier. Your best solution now is to have two inches of closed cell spray foam applied directly to the underside of your roof steel, making certain they do not block ridge vents. Without this thermal break, expect to end up with damp insulation.

If your builder installed vented soffits on your building’s end overhangs, you need to find a method to block them off – otherwise your attic will not vent properly.

In regards to ceiling vapor barriers, Joe Lstiburek (building scientist and founding principal of Building Science Corporation) says plastic vapor barriers should only be installed in vented attics in climates with more than 8,000 heating degree days. Even in South central Wisconsin, you are not to this point.

You’ll want to verify a correct ratio of air intake from soffits to air exhaust at ridge (chances are good your builder did not). At least 40% and no more than 50% of your attic’s net free ventilating area (NFVA) should be at the ridge. You may need to block off some of your sidewall eave vents to get the ratio correct.

I would also recommend you blow in rockwool insulation in your attic rather than fiberglass. Fiberglass insulation loses R value when outside (attic) air temperatures are low and is also affected by even small amounts of moisture.

Lack of Adequate Attic Ventilation

Lack of Adequate Attic Ventilation is Sadly Becoming a Recurrent Theme

If only providers of poorly designed pole barns could be keel hauled…..

Reader AARON in CASPER writes:

“Hi there, I have a 40×104 pole barn. It has 16 foot sidewalls with rafters every 4 foot on center for snow load. The entire interior of the building is spray foamed to about 1 inch thickness. I want to install a ceiling under the rafters and put in r 38 insulation on top. I know that there were ridge vents when the building was put together, however the guy who spray foamed sprayed over the vents. I plan to clean that out. My question is are just those ridge vents enough for ventilation or do I need additional intake vents. The building does not have an overhang or soffits so they would not be easy to install. Do you have any suggestions?”

Mike the Pole Barn Guru says:

You certainly have a challenge at hand.

Here are requirements for adequate ventilation: https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/

You could add 1000 square inches of NFVA (Net Free Ventilating Area) vents in each gable end and it would meet Code (along with cleaning out your ridge vents for an exhaust), however this would prove to be a very poor design solution as your attic air flow will be highly constricted once you get past first truss in from each end.

Short of a major rework to add enclosed ventilated soffits, your best design solution if going to be to have a conditioned attic – besides, one inch of closed cell spray foam is not adequate to control condensation (it usually takes no less than two inches).

To get to R-38, you could increase closed cell spray foam to a total of 5-1/2″ or add another inch of closed cell plus 6-1/2″ of open cell.

Before considering adding a ceiling, confirm your roof trusses are adequate to carry extra weight. They need to have a minimum BCDL (Bottom Chord Dead Load) of 5 psf to support ceiling joists 24 inches on center and 5/8” sheetrock.

Things My Pole Builder Didn’t Discuss With Me

Things My Pole Barn Builder Didn’t Discuss With Me

Somehow I feel as if this should be a Jeopardy question for $400…..

Reader MATT in BUFFALO writes:

“Hi there, my pole barn has recently been constructed and I’m now looking forward to insulating and finishing the inside. My hope is to drywall all interior surfaces including the ceiling. I realized as we were finishing the build that this was never really a discussion with our builder, specifically for the ceiling. I would like to add 2×4 or 2×6 ceiling joists 24″ on center and hang 5/8″ drywall for my ceiling finish and insulate somewhere in the r38 range with fiberglass. I do not intend on having any storage above the bottom chord, but will leave access to the space. My truss plans show a bottom chord dead load of 5.0 psf and states in the notes that the truss has been designed for a 10 psf bottom chord live load, although under loading it shows a bcll of 0.0. It also mentions for bottom chord bracing that a ‘rigid ceiling directly applied or 5-8-15 oc bracing’ is allowed. I think 5.0 psf leaves me just barely enough to finish this how I’d like, but I’d like to run it past someone with experience. I’ve unfortunately had the hardest time getting a hold of the truss designer/manufacturer. Thanks!!”

Mike the Pole Barn Guru writes:

Oh – things somehow never being discussed before a build gets started…..

Don’t get me wrong, I am not blaming you.

Any responsible builder or building provider should thoroughly know their client’s eventual end use for their building and offer some reasonable options to achieve those goals. Sadly – so many “professionals” know only how to sell on a cheap price rather than value added benefits to potential building owners.

Let’s run through possible challenges –

Condensation control. Unless some provision was made to keep warm moist air from rising and touching underside of roof steel, it will “rain” in your attic. Solutions at time of construction (in order of preference) would be: a factory applied integral condensation control (https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/), a well-sealed reflective radiant barrier (it really isn’t insulation https://www.hansenpolebuildings.com/2014/04/reflective-insulation-wars/), installing over solid sheathing (OSB or plywood) with 30# felt or a synthetic underlayment, or Metal Building Insulation (https://www.hansenpolebuildings.com/2011/11/metal-building-insulation/).

If no provision has been made, your option now would be two inches of closed cell spray foam applied directly to the underside of roof steel.

Ventilation. When creating a non-conditioned attic space, it must be adequately vented. Gable vents can be Building Code conforming, however from a practicality standpoint, they only ventilate well closest to their location (building ends). Best design solution is intakes at eaves, exhaust through ridge. Here are your requirements: https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/.

Most pole barn trusses are designed for a one psf (pounds per square foot) bottom chord dead load (BDCL) – inadequate for any type of ceiling. On truss spans of up to and including 40 feet, we include a five psf BCDL as a matter of practice (too many clients decide later on they want a ceiling) and if we know in advance a ceiling is to be installed, we use 10 psf BCDL. You have been fortunate to have at least a five psf BCDL. Your 10 psf bottom chord live load is a non-concurrent (assumes no other live loads are being applied such as snow) one and basically is there to provide a minimum degree of structural integrity allowing for occasional access to an attic space for maintenance purposes.

Depending upon span between trusses, size and grade of ceiling joists can be looked up at www.codes.iccsafe.org/content/IRC2021P2/chapter-8-roof-ceiling-construction#IRC2021P2_Pt03_Ch08_SecR802 scroll down to Table R802.5.1(1). In order to support 5/8″ sheetrock, ceiling joists should be spaced no greater than 24 inches on center.

Your actual dead loads will be roughly 1 psf for truss bottom chord itself (includes minimal wiring, lighting and truss bracing), 2×6 ceiling joists 24″ o.c. (I use one psf although actual load is slightly lower https://www.hansenpolebuildings.com/2013/02/2×6-lumber/) and your blown fiberglass (about a pound per cubic foot), so you should be okay. Cellulose or rock wool insulation are about three times as heavy as fiberglass, pushing to BCDL capacity, although my recommendation would be rock wool over other products as it is unaffected by moisture (fiberglass with even 1.5% moisture content can lose roughly half of its R value).

Ceiling Insulation, Truss Spacing, and Custom Multi-use Barn

This Wednesday the Pole Barn Guru answers reader questions about best way to insulate a vaulted ceiling, truss spacing, and the possibility of adding a small living quarter to a horse barn.

DEAR POLE BARN GURU: With a vaulted ceiling, how do you insulate it if you plan to spray the tin roof with closed cell foam. Was planning on bat insulation on the lower cords of the trusses if needed. what about venting if you spray foam the tin roof? CHRIS in DORCHESTER

DEAR CHRIS: Saline County is located in Climate Zone 5A. As such conditioned buildings require R 60 attic insulation.

You can either:

Have a conditioned attic space – using closed cell spray foam at least two inches thick against underside of roof deck, then adding open cell spray foam or unfaced rock wool batts to get to required R value. This assembly will not be ventilated.

Or

An unconditioned attic. If you have no other method of condensation control, then again place two inches of closed cell spray foam directly to roof steel interior. Vent eaves and ridge, then blow in R 60 of fiberglass across attic. Insulation baffles will need to be placed at eaves to allow for at least an inch of unobstructed air flow above blown in insulation.

 

DEAR POLE BARN GURU: Hello Mike, I have a question regarding a post frame building I would like to build. the size is 40′ x 32′ x 16′ with 6/12 roof pitch. I am planning to use trusses at 2′ foot centers. my question is regarding using 3 tab composition shingles for my roof covering (I have a HOA that will not allow metal roofs), what special considerations might I need to take with respect to where the trusses attach to the top of the post frame wall? the posts will be at 8′ centers and standard girts installed. I was thinking that perhaps increasing the dimensions of the top girt would be necessary. I would appreciate your thoughts on my intentions. I have enjoyed your YouTube videos as well. Sincerely MARK in CODY

Ask The Pole Barn GuruDEAR MARK: Thank you for your kind words about our YouTube videos. https://www.youtube.com/user/HansenBuildings
Personally, I would place double trusses to bear directly upon columns spaced every 10 to 12 feet with purlins on edge, joist hung between truss top chords. This design results in fewest number of holes needing to be dug, as well as fewest pieces of materials to have to install. It also allows for wider door openings.

Doing as you propose, truss carriers (headers between columns to support trusses) would need to be adequately sized by your building’s engineer in order to carry imposed loads without failure or undue deflection.

 

About Hansen BuildingsDEAR POLE BARN GURU: Do you all have barns with living quarters? Not looking for a barndominium, per se, but a restroom with a shower and a living room in addition to 4 stalls and a tack room. we plan on staying there at first while we build the main house on the property, then use for guests or storage. SARAH in SARASOTA

DEAR SARAH: We have provided a plethora of barns with living quarters and every building we provide is custom designed to best meet our client’s wants and needs.

Typically, you should expect to have to two-hour fire separate barn from living area, meaning you cannot go directly from one occupancy to another without going outside in order to do so. For this reason, many of our clients have opted to have a roof only breezeway area between these dissimilar occupancies.

Advice on Retro Insulating a Minnesota Pole Barn

Advice on Retro Insulating a Minnesota Pole Barn

Reader RYAN in ELK RIVER writes:

“Happy Thanksgiving! I am working on insulating a pole barn that is on a property I bought. I framed between trusses with 2×6 and plywood on top. I plan to have 3″ of foam blown in. Is there anything I need to be aware of if that is the route I take? Also, in the walls I installed R6 foam board between the purlins, and R 19 fiberglass Batts in the wall cavity. Should I install vapor barrier? I plan on a 42″ steel wainscot around the bottom, with drywall on the rest of the wall and ceiling. 

Thanks for your input! There seems to be lots of different answers out there from the research I’ve done.”

Mike the Pole Barn Guru responds:

In Minnesota, closed cell spray foam has to be so thick to meet R value requirements, it normally makes it impractical as a design solution. If you do opt for spray foam, use closed cell (rather than open) and spray directly to the inside of steel roofing and/or siding, for best results. If you are creating a dead attic space above an OSB ceiling, closed cell spray foam can be applied to underside of OSB, however space above must be adequately ventilated (ideally with eave intake and ridge exhaust points). You also need a provision for condensation prevention on the bottom of roof steel (if one is not already present).

In walls, you want only a single vapor barrier. If your foam boards were properly sealed, then they are your vapor barrier and you should use unfaced batts to fill balance of wall insulation cavity. My preference would be rockwool, rather than fiberglass, as it is not affected by moisture.

Be aware, your building is now going to dry to inside, so be prepared to invest in mechanical dehumidification.

Corner Trim, Metal Roof Install Issue, and Insulation Solutions

This Wednesday the Pole Barn Guru answers reader questions about what trim to use on building corners, an issue of installing metal to roof that is extremely out of square, and best options to insulate a building.

DEAR POLE BARN GURU: Good afternoon! Looking to see what trim to use on the corners? https://www.hansenpolebuildings.com/2015/10/horizon-steel-siding/  Sincerely, KYLEIGH

DEAR KYLEIGH: Order standard Corner Trims and place pre-formed foam Outside Closure strips between horizontal steel siding and trims.

 

DEAR POLE BARN GURU: How much more difficult would it be to put the metal roof on if you can’t square the roof trusses. Because the posts were not cemented in properly. We are 8′ out of square on a 24’x50′. Would it be possible to square being that far out? TOM in BLOOMSBURG

DEAR TOM: I want my roof planes to be square within 1/8th inch before attempting to run steel. At 8′ out of square, I would have pulled out all offending posts and started over again. What you have will be impossible to properly roof and would require cutting every sheet of steel at eaves to even get a straight overhang line.

 

DEAR POLE BARN GURU: Just finished 40x60x16 pole barn and am looking to insulate. Building wrap was installed on exterior walls and roof has double bubble. Wondering how to manage moisture inside the building. Slab is insulated under as well as a vapor barrier. Interior walls and ceiling will be finished with steel liner panel. I’d like to spray foam entire building with open cell spray foam walls and roof deck. Would I need to install a vapor barrier between foam and steel liner panels? Building has attic trusses and the room will also be conditioned separately from garage space. Thanks KYLE in COXSACKIE

DEAR KYLE: I would not spray foam to building wrap, as it causes more problems than it solves. https://www.hansenpolebuildings.com/2020/04/spray-foam-insulation-3/
For walls, I would use unfaced rock wool batts, with a well-sealed interior vapor barrier. You do not need a vapor barrier between ceiling liner panels and attic spray foam. Personally, I would blow in fiberglass above ceiling liner panels and ventilate the dead attic space.

It might be necessary to mechanically dehumidify your building.

Insulation and Ventilation, Straw Bales, and Double Bubble

This week the Pole Barn Guru answers reader questions about using cardboard and heavy plastic to vent and insulate a pole building, use of straw bales an insulator, and best way to ventilate and reduce roof noise.

DEAR POLE BARN GURU: On my 42×63 2 story pole building (heated first floor) I have trusses 9’ o.c. standard roof purloins 2’ o.c. I was wondering if I could use cardboard up against steel roofing for venting air flow of the humps in the steel roof panels (standard steel w/ 1” humps not standing seam ) then install heavy plastic on bottom of purlins and fill cavity w/ cellulose blown insulation. Would this work correctly for ventilation of steel and insulate correctly. Combination of being cheap/frugal and I have free heavy cardboard from washers/dryers/refrigerators to fit between purlins. Greatly appreciate your opinions. Thank you. BEN in EDEN

DEAR BEN: Code requires a one inch minimum of airflow across your entire roof surface above batt insulation. Air flowing only at steel ribs would be inadequate to meet requirements. Assuming you have 2×6 roof purlins, 5-1/2 inches of blown cellulose would give you roughly R-19.25. You would be better served by using 2-1/2 to 3 inches (R-17.5 to R-21) of closed cell spray foam applied directly to underside of your roof steel, as it does not have to be vented above.

 

DEAR POLE BARN GURU: Hi, I read your post on bale infill with a pole building (https://www.hansenpolebuildings.com/2013/04/straw-bale-homes/). When I called to get more info, the rep told me that Hansen strongly advises against it, but he also said he hadn’t heard about that idea. Is there someone there that has worked with a client who has used straw bale walls to infill between the posts? KEVIN in RENO

About Hansen BuildingsDEAR KEVIN: Your call happened to be routed to one of our newer Building Designers. Post frame construction is highly complex, with a literal unlimited number of possibilities, this being one your designer was unfamiliar with.

In general straw bale homes seem to have been a passing fad, however if you strongly feel this is your best option, please call again and ask to speak with Rachel – our most senior Building Designer, and she can assist you better.

 

DEAR POLE BARN GURU: I am looking for a underlayment for my pole barn. I have metal roofing with horse stables below. There are no side walls to my pole barn. It’s all about ventilation for the animals here in NC. It’s supposed to add a few degrees in R value. It also helps deaden the sound of rain. Everyone talks about double bubble but this is supposed to be different. Thank you, FRANCES in TRYON

DEAR FRANCES: Without having to pull off your building’s roof steel, install some fashion of condensation control then reinstall it – there is only one practical solution – two inches of closed cell spray foam applied directly to underside of your steel roofing. This would provide an R-14 insulation value. It is unlikely to have an effect on reduction of noise from rain, as it is not good at blocking sound waves. “Double bubble” offers little to no R-value and would require being installed between framing and roof steel.

 

Skylight Width, Gable Fans, and Post Spacing

This Wednesday the Pole Barn Guru answers reader questions about the standard width of a skylight, gable fans for ventilation, and post spacing for a roof only building.

DEAR POLE BARN GURU: What is the standard width of a skylight on a pole building?

ROBERTA in DAKOTA

DEAR ROBERTA: In most instances pole building skylights are fiberglass or polycarbonate panels with same configuration as 3′ width net coverage steel roofing. For some extended reading on skylights please visit: https://www.hansenpolebuildings.com/2012/01/skylights/

 

DEAR POLE BARN GURU: Just completed a 36×84 x 14′ high pole building. Self designed. I sheeted the roof, both gable walls, and the front wall for shear and strength using 1/2″ cdx. I used ice and water shield under the roof and house wrap on the walls. Concrete slab with 6mil vapor barrier underneath. No insulation. Also, no ventilation. Noticing I need ventilation, before things get moldy etc. I’m considering putting a 24″x24″ 5000cfm powered gable fan on the east side, and a 24″x24″ intake vent on the west side. Would this be adequate to keep condensation and moisture at bay? TODD in PORT ORCHARD

DEAR TODD: Lack of ventilation is a harbinger of future condensation problems with well-sealed buildings. Your building has roughly 51,000 cubic feet of interior air volume, meaning a 5000 cfm powered fan will turn your air roughly every six minutes (or 10 times per hour). This should be adequate, however a greater capacity might be worth considering. You will also want to look at actual NFVA (net free ventilation area) of your intake, as lack of intake area can restrict performance of your exhaust fan.

 

DEAR POLE BARN GURU: Hi, My name is Joe. I’m trying to build a pole barn with in an area of Washington that has a snow load of 15 PSF.  The building is 24′ wide by 38′ deep with 14 feet clear height. no side walls. Seems like spacing varies quite a bit from 8 ft to 12ft. Thought I would see what u would suggest for this?  I was thinking about doing 12 ft or maybe even 10 ft.  Any thoughts would be much appreciated? JOE in WASHINGTON

DEAR JOE: I would look at doing bays of 12′ – 14′ – 12′ first, however you should discuss options with whoever is going to engineer your building plans. Depending upon what you will be using this building for, it may be less expensive to cover one or both 24′ endwalls from roof to ground, than to have a roof only. A Hansen Pole Buildings’ Designer will be reaching out to you to discuss your needs, as we have provided roughly 1000 fully engineered post frame buildings to our clients in Washington State.

Insulating an Apartment in a Steel Truss Pole Barn

Insulating an Apartment in a Steel Truss Pole Barn

Reader JONATHAN in AUGUSTA writes:

First of all, thank you for having a wonderful resource put together in one place for fellow DIYers such as myself. I am currently in the process of constructing a 30x60x11 pole barn. So far I have the roof put up; metal trusses with 2×6 wood purlins, synthetic underlayment and metal R panel. I will be building a 30×24 “apartment” inside, think box inside of a building with the remainder being used as a shop. 3 sides of the apartment will be the exterior walls of the pole barn with the 4th side splitting the barn almost in half. I will have mechanical ventilation in the form of an exhaust fan cut into the side of the building sized to the 30×36 portion with an appropriately sized louver that I intend on using when necessary when working in the shop. The apartment will have HVAC.  I am looking for the best method to insulate the roof. Vented/unvented? Spray foam? Radiant barrier nailed to the bottom of the purlins? I plan to house wrap the walls and install Rockwool to insulate them but was unsure about the roof. There are so many conflicting methods out there I just want to get it right the first time. I am in a hot humid part of the south. I look forward to your thoughts on this and thank you in advance for any advice.”

Mike the Pole Barn Guru advises:

Thank you for your kind words. Obviously we are somewhat self-serving as many of our blog readers understand Hansen Pole Buildings caters to those who want to DIY and realize there is a good chance we can assist them in reaching their ultimate goals, without undue road bumps and pot holes.

You have some challenges happening here (aka pot holes), in part due to your choice of roof systems. Those trusses are not designed for a ceiling and 2×6 roof purlins at this span will deflect too far to allow for sheetrock to be applied to them, or to give an adequate depth insulation cavity.

If I was in your position, I would frame in 8 or 9 foot tall walls for apartment area, with ceiling joists above. I would then use unfaced rock wool batts between ceiling joists to R-30 (Climate Zones 0 and 1) or R-49 (Zones 2 and 3). Use 5/8″ Type X sheetrock for apartment ceiling and wall between apartment and shop (personally I like 5/8″ everywhere).

Ventilate balance of building otherwise you will most probably experience condensation challenges.

Moisture Control, Insulating Existing Structure, and a Post Rot Fix

Today the Pole Barn Guru answers reader questions about moisture control, insulating a building with a ridge vent, and a solution for replacing posts that have rotted out.

DEAR POLE BARN GURU: Thanks for the abundance of technical information you provide your readers. Like many of them, I inherited a pole barn with the same ceiling sweating, heat, cold issues and need a post construction solution. The slab sweats only in some places. I have a typical wood post with 2×4 horizontal purlins, wood truss and purlin roof, and metal skin walls and roof. My goals are, #1 stop the moisture inside, #2 insulate for moderate comfort (no codes to comply with and I can heat with a wood stove and abundance of wood) , and #3 if I can afford it, skin the walls with T-111 or other wood for an attractive look inside. I did not see any suggestions about double-faced radiant barriers in your other articles. Do you think expanded polystyrene cut to fit in the 1.5 inch cavities to flush with purlins, and then add the radiant barrier (bubble type) stapled over that directly to purlins would be appropriate and not trap moisture? If so, should I allow and air space between the polystyrene and radiant barrier? Many thanks, Mr. Retired…finally! JOHN in CHEROKEE VILLAGE

DEAR JOHN: Thank you for your kind words. If your slab sweats at all, it is likely there is no vapor barrier under it and it would behoove you to apply a sealant. 1.5″ expanded polystyrene (EPS) boards cut to fit tightly and with all seams tightly sealed would give you some degree of insulation (roughly R-7.5 other than at girt and purlin locations). You could add unfaced rock wool batts to increase insulation. Radiant barriers provide next to no insulation value and only function if seams can be perfectly sealed, we’ve actually opted to no longer offer them to our clients.

Unless you want to heat area in triangle of trusses, you may want to consider insulating at ceiling level, then vent dead attic space above.

 

DEAR POLE BARN GURU: Hello Mike. I came across your website while trying to learn more about what to do with the ridge vents in a pole barn when you plan on insulating it with closed cell foam. My wife and I purchased a property that has a 36w x 48L unconditioned pole barn with 8 skylights, a couple of ridge vents and (2) sets of huge doors on each end. While we know this will never be a tight building, we need to insulate it for our pets (10) dogs and (11) cats, and for a hangout area for us to spend time with them rather than inside our home.

We have a high-end American Standard heat pump split system that will condition the entire space.

Would you be able to give me any advice on what you recommend I do regarding the existing ridge vents? I’m not sure if I should insulate around them and leave them as they are…open. Or, should I temporarily trim out around them and seal them for the time being?

Any information you could provide me on this topic would be greatly appreciated. ROGER in HOUSTON

DEAR ROGER: With those large sliding doors, your investing in closed cell spray foam may be for naught. If your expectation is to be able to control any sort of heat loss/gain you should consider replacing them with insulated steel sectional overhead doors.

On to your question – seal off ridge vents and spray foam across skylights (or, even better) replace them with steel roofing before insulating.

 

DEAR POLE BARN GURU: What are my options on repairing 32×40 all 6×6 posts are rotted off ground level. Floating slab, perma colum, helical peir, or strongway sleeve. CHAD in GREAT BEND

DEAR CHAD: I would repair one column at a time. Temporarily support roof system being supported by a column. Cut column off above point of decay. Excavate embedded portion of column and remove – hole being dug to be at least below frost line. Insure bottom of hole is firmly compacted. Place a sonotube in hole, attach an ICC approved wet set bracket to bottom of column and backfill with premix concrete. Compact granulated fill around sonotube in six inch lifts. Repeat at each column.

 

 

Footings, Mechanical Plans, and Hay Ventilation

This week the Pole Barn Guru answers reader questions about concrete footings for a lean-to addition, how to incorporate plumbing, electrical, and HVAC plans into to process, and proper ventilation for a hay barn.

DEAR POLE BARN GURU: We are putting a 10′ Lean-to on a Steel Framed Building. We will be using 4×6 posts spaced 10′ with 18″ holes. My question is about footings. I was hoping to tamp the bottom of the hole, add a bit of gravel, place post, add quickrete, and back fill. I am hoping to avoid filling the entire hole with concrete to save some money. If there are better ways I am open to them just looking for cost effectiveness, if possible. Thank you! PETE in UNIONVILLE

DEAR PETE: Any building is only as strong as its foundation, so this is not a place to be penny wise and pound foolish. Code requires minimum six inch thick concrete footing, or a Code approved alternative (here is an example https://www.hansenpolebuildings.com/2014/05/footingpad/).

Subject to approval from your building’s engineer, I would recommend supporting your building columns up eight inches from bottom of hole, then monopouring with concrete to give at least an 18 inch total depth of concrete. Done in this fashion, you could pour roughly 10 holes with a yard of premix. Balance of hole above this bottom collar can then be backfilled with compactible material.

 

DEAR POLE BARN GURU: When I order plans and the pole barn kit from Hansen and work as my own general contractor, how do people generally build HVAC, plumbing, electrical, etc. into the plans to take to the county to acquire permits? Do I have to get plans from those contractors and then take it to a drafter to get drawn up for approval for permits? JOHN in LAPINE

DEAR JOHN: Our floor plan team can add plumbing and electrical for a nominal fee – challenge is, your subcontractors will ignore this entirely. I have always had best results having these subcontract trades submit their own drawings when they apply for their permits (these permits are outside of your structural permit).

 

DEAR POLE BARN GURU: Have a 24ft x48ft pole barn that we store hay in. The hay is always getting moldy, hay sits on OSB wood which sits on a steel grate platform, 1ft above concrete floor. Barn roof is OSB wood with felt and shingles with a ridge vent. Sides of barn are steel with OSB wood on inside. Am thinking of building a new barn with a hay loft, but was given a suggestion to contact you first for a possible solution. Barn is in northeastern Ohio, very humid in summer. We check the hay before we store it and the moisture level is fine. I even thought of enclosing hay area and putting in a dehumidifier. Any ideas would be appreciated. Thank you, STEVE in NORTH RIDGEVILLE

DEAR STEVE: A hay barn needs proper ventilation to expel moisture from hay respiration. Hay barns are typically dependent on natural ventilation to get air exchange, so proper orientation can be critical. Typically, a hay barn should be oriented so open eave sidewalls are perpendicular to predominant wind direction.

For barns with enclosed sidewalls, enclosed vented sidewall eaves and a vented ridge are critical design elements to allow for passive ventilation. Air enters through eaves and exits through ridge vent with excess moisture.

Choose a location away from swampy areas or at bottom of a hill, as it will require more costly drainage. Gutters or rocked ditches close to sidewalls should be included in planning costs. Hay barn floor should be at least six to eight inches higher than surrounding ground level.

With a concrete slab-on-grade floor, it is crucial to have a well-sealed under slab vapor barrier.

When the Problem is Not the Problem

When The Problem, Is Not The Problem

Captain Jack Sparrow’s quote is close in this instance. Please read on…..

RYAN in MISSOURI writes:

Hi Mike – I spoke with Brenda at your office and she said you may be willing to help me out. I don’t expect you to just give me free advice though, so if you were willing to provide me with some feedback on my “project”, I would like to pay you via Venmo or maybe your office could work up an invoice and I can pay you guys with a credit card. 

I built a 36×48 pole barn 5 years ago and didn’t account for adequate ventilation and now I want to fix the problem (I’m sure you’ve heard that line countless times before). I read one of your blog posts to get a head start on working up a plan of attack to keep it dry in there. I’m hoping you could check my work and either take a phone call from me or provide guidance via email (again, I can shoot you some money for this, please just let me know what sounds acceptable to you). 

Specs on the barn (I’ve included some older pics from before I installed the gutters and the electric below):

  • Location: central Missouri
  • Dimensions: 36′ wide (gable and door end) x 48′ long
  • No overhangs or soffit 
  • Two 8 ft ridge vents
  • Gutters down the eave/length sides to push water away from the “foundation” 
  • Currently no vents on the eave/length or gable sides or anywhere really… just some gaps around the trim and the base of the building where you can see daylight. 
  • The barn has electricity and the floor is just gravel. I have a junction box run to the gable on the south side (over the door ready to accommodate a vent fan). No animals inside. Just old tractors, some tools, and four wheelers. I don’t plan on putting in concrete or any HVAC. Things out there can get hot or cold, I just don’t want it raining from the ceiling anymore. 

Using your blog post, I tried to calculate what I would need as far as the CFM rating of the fan and the square inches of vent space (table of numbers below)

Questions: 

  • Before installing a fan, I should ask: is a fan even necessary? Seeing as I don’t care about HVAC, temperature or even critters getting in there, could I get by with just strategically placed vents and wind? 
  • If I do need a fan to generate enough circulation, does my math below look ok? 
  • Would the Airlift T16 with a 3060 CFM adjustable fan speed and a humidity detector or something like it work ok? 
  • Where would you recommend I place the vents (and I’m happy to go overkill on them if needed) in order to achieve the best results? 

Thank you so much for your time!”

Mike the Pole Barn Guru writes:
Thank you for your generous offer of payment Ryan, however I answer all sorts of similar questions for free.

Now, the good news and bad news….

Good news is you do not have a ventilation problem, no reason to invest in any possibly expensive power ventilator fans.

Bad news – as you have found out, it rains from your ceiling. What you have is a condensation problem. Warm, moist air inside of your building is rising. It contacts with cooler roof steel, condenses and rains. This is much easier solved at time of construction than now (as well as less expensive). Roof steel ordered with an Integral Condensation Control factory applied would have been highly affordable, as well as easy to install.

Short of removing and reinstalling your roof steel to add a thermal break between purlins and steel (both costly and labor intensive), I would recommend having two inches of closed cell spray foam professionally applied to the underside of your roof steel.

When you do pour a concrete slab inside, be sure to add a well-sealed 6mil or thicker vapor barrier underneath.

When Friends Buy Buildings From Others

When Friends Buy Buildings From Others

Long ago, in a galaxy far away……well actually it is in our galaxy.

Jeff and I met roughly 40 years ago, when his mother and my father dated. About 15 years later, I was Jeff’s sponsor when he became a member of Spokane Valley Rotary. In recent years, Jeff invested in a pole building and I was unaware of it until now – when he reached out to me with a challenge.

Jeff writes:

“Hey Mike! I have read the blog a lot and tried my best to understand the insulation issue that seems to get asked of you the most, but I’m just a little slow on understanding. Attached are three pictures of my pole building ceiling that I want to begin insulating. It is 36′ x 40′ with 14′ eaves on a 5×12 pitch. As you can see there is OSB under the steel roofing. The sides are steel from the top down to 4′ where there is OSB and hardiplank siding. Concrete floor. You can see some mold stains from the first year that I did not have a floor poured yet. For the walls I figure I can just use faced fiberglass batt rolled insulation without a vapor barrier then finish with drywall. Not sure about the ceiling. Can I just use rolled insulation? Then drywall or OSB over that? Vapor barrier? Do I need to have the 1″ = 2″ ventilation space between the OSB and the fiberglass? Only one side has the vent opening to the eave, the other side has an open lean-to. Thanks.”

Mike the Pole Barn Guru writes:

If your intent is to insulate between roof purlins with batts, Code requires a minimum one inch air space between insulation and roof deck (in your case OSB) continuous from eave to ridge. There is no way for you to accomplish this, as your building’s purlins block any possible airflow route. Your choice for insulating with a roof plane really comes down to closed cell spray foam. Other issues could be what sort of a dead load your roof system is engineered for. Typically post frame roof trusses are designed for only a five pounds per square foot (psf) top chord dead load with OSB. This would not be adequate to attach OSB, plywood or sheetrock directly to the underside of purlins. Even if trusses have adequate load capacity, your roof purlins appear to be 2×6 and would overly deflect with sheetrock applied – resulting in popped screws and failed taped joints.


In an ideal world, your roof trusses would have been designed for a 10 psf bottom chord dead load. This would be adequate to support a sheetrock ceiling and fiberglass insulation could be blown in on top of it. If this route is taken, you would need to provide adequate ventilation.


A solution could be to reach out to whomever manufactured your building’s roof trusses and inquire about an engineered repair to increase loading. These repair drawings are usually relatively affordable, however repairs often entail a fair amount of time, effort and materials.


As you have no Weather Resistant Barrier (Tyvek or similar) between wall framing and siding, I would recommend using unfaced rock wool or mineral wool batts as they are unaffected by moisture (unlike fiberglass) with a well-sealed 6mil clear visqueen vapor barrier on inside, then your drywall.

Screw Penetration, Truss Carrier Requirements, and Roof Insulation

Today’s Pole Barn Guru answers reader questions about screw penetration into decking/substrate, header aka truss carrier requirements, and a proper roof insulation solution.

DEAR POLE BARN GURU: Should the screws for exposed fastener metal panel roofing COMPLETELY penetrate the 1/2″ plywood decking/substrate? STEVE in WARREN

DEAR STEVE: For through screws, they should not only completely penetrate any substrate, but also at least an inch into underlying purlins. Relying upon screws into decking only could prove to be a failure looking for a place to happen in a severe wind situation.

 

DEAR POLE BARN GURU: On a 14’ x20’ building with 4×6 post 8’ tall what are the requirements for the header beam or beams? Can I use two 2x10s one out and one inside? TIM in STATE ROAD

Ask The Pole Barn GuruDEAR TIM: Header beam (aka truss carrier) requirements can be determined by a Registered Professional Engineer and are based upon this formula:

(Roof live and dead loads) x (1/2 span of truss + any eave overhang in feet) x (column spacing in feet squared)

Divided by

8 x Sm (Section modulus of proposed beam) x Fb (Fiberstress in bending of proposed beam) x Cd (Duration of Load)

If resultant is less than 1, then beam is okay.

Here is an example, based upon assumption your building is in a minimal snow area, steel roofing over purlins, no or light weight ceiling) columns are every 10 feet, one foot overhangs and available lumber is 2×10 SYP #2

(20 psf + 10 psf) x (14’/2 + 1’) x 10’^2 / 8 x 21.3906 (Sm of a 2×10) x 800 x 1.15 = 0.15 <= 1

For sake of this example, a single 2×10 #2 SYP would be adequate in bending. It may not be adequate for meeting required bearing area (can be confirmed with truss manufacturer).

Beams and connections should also be verified for adequacy against uplift forces, as well as deflection.

 

DEAR POLE BARN GURU: I’m about to build my ‘Miracle Truss’ building which uses steel trusses with lumber purlins/girts. I have a concrete slab with 2″ Styrofoam and radiant heat to provide some warmth in the winter. I’m thinking of using foil/single bubble vapor barrier in between the roof sheeting and wood purlins. In the future I’d like to add bat insulation to the inside of the roof. For the walls I’m not sure if I should use a foil radiant film – non-permeable…or if I should instead use house wrap like ‘Tyvek’. Again, as time and $$ allows I’d like to add bat insulation and maybe OSB half way up the walls. I’d appreciate your professional opinion on how best to ‘wrap’ my building and also ‘future proof’ it in case I happen to win the lottery and can afford to fully insulate it someday. Thank you. RICK in HILLSBORO

DEAR RICK: Code will not allow you to place batt insulation between your purlins unless you have at least an inch of continuous airflow above from eave to ridge. Impossible to do given orientation of roof purlins.

I would use two inches of closed cell spray foam directly to underside of your roof steel. Later, you could fill balance of cavity between purlins with unfaced rock wool, or open cell spray foam. For your walls, use a Weather Resistant Barrier (aka house wrap) and you can add either Kraft faced batts or unfaced batts with a 6mil vapor barrier on the interior at a later date.

 

Roof Insulation, a Riding Arena, and Closure Strips

Today’s Pole Barn Guru answers reader questions about insulating a roof to keep exposed trusses, the size limits for and equestrian riding arena, and whether or not to use closure strips between the gable (rake) trim and siding.

DEAR POLE BARN GURU: I have a 30×40 post frame building with cathedral style trusses. I really like the open look and don’t want to cover them with a ceiling. I want to insulate against the metal roof with vinyl faced blanket insulation to give a nice finished look. The roof currently has bubble wrap which I’m told I should remove so I don’t have two vapor barriers. Question is, if I remove the bubble wrap, is it ok to lay just blanket insulation between trusses or should I try to fill the 1.5″ space between purlins with foam board then blanket insulation over top of foam board. Or would filling the 1.5″ space with spray foam, then blanket over that? Thanks for any advice. BRIAN in LANDISVILLE

DEAR BRIAN: Only way to properly do as you propose is to remove bubble wrap, then have 2″ or more of closed cell spray foam insulation applied directly to underside of your steel roofing. Balance of insulation cavity can be filled with either more closed cell (best R value) or rock wool insulation (as it is impervious to moisture).

 

DEAR POLE BARN GURU: Need an open cover 150 L x 75 W x 13 H to function as a cover for an equestrian arena. Can a pole barn get this big? And if not what is the largest size we can go. JEFF in PINELLAS PARK

DEAR JEFF: While we have provided post frame riding arenas with up to 100 foot clearspans, in most geographical areas, wood truss fabricators are limited to building and shipping lengths up to 80 feet and overall truss heights of 12’.

Interior Clearspan Arena

For extended reading on riding arenas, please visit: https://www.hansenpolebuildings.com/2012/07/the-perfect-indoor-riding-arena/

 

DEAR POLE BARN GURU: Should I use closure strips between the gable trim (rake trim) and siding? The siding is tuff rib. STEVE in WARREN

DEAR STEVE: Standard form fitted closure strips are sized to only fit perfectly when applied at 90 degrees to length of steel panels. When going up rake trim, these closure no longer fit, however we have a perfect solution Emseal! https://www.hansenpolebuildings.com/2016/03/emseal-self-expanding-sealant-tape-closures/
To acquire, please reach out to Materials@HansenPoleBuildings.com along with lineal footage required and ship to zip code.

 

How Do I Ventilate My Barn’s Attic?

How Do I Ventilate My Barn’s Attic?

Right up there with curing condensation issues is how to properly ventilate a pole barn’s dead attic space.

Reader CURTIS in TRENTON writes:

“I have a 40’x60’ outbuilding that doesn’t have soffit vents for fresh air intake and the ridge cap has solid foam closures along the length of both sides of it so I have no air exhaust either. Basically just whatever air leaks are within the building. My plan is to fully finish the inside of my building. (Insulated walls and OSB sheathing and a metal ceiling with a blown in r-38) I plan on making it as air tight as possible. This building will be heated some over the winter as well. My roof panels also have the “drip X” felt like material that is attached to the underside of the panels. I believe this acts as a vapor barrier to keep the roof from condensing. My question is since I don’t have soffit vents or a vented ridge cap do you recommend adding 2 gable vents? If so, what size? I know there’s a formula for sizing them. I believe it is the square footage of the building, (40×60=2400/300=8 sq ft) so would be adding a 4 sq ft gable vent on each end of the building be sufficient? 4 sq ft of intake and 4 sq ft of exhaust totaling 8 sq ft of ventilation? Or should I do a gable vent on the west side of my building for air intake and a shutter exhaust fan wired to a humidistat/thermostat on the east side (away from prevailing winds) to pull hot air from the attic. I believe there’s a formula for this too to determine the fan’s cfm rating and the gable vent size. (40×60=2400×0.7=1680CFM) 

Add an additional 15% (1680×1.15=1980CFM) for a darker colored roof. My roof is forest green. So an exhaust fan with a minimum rating of 1980CFM/300=6.44 sq ft, which would determine the gable vent size on the west end of the building. Examples: 30”x32”=6.65 sq ft or 26”x36”=6.48 sq ft) My question is are these formulas correct and which one do you recommend using? Two gable vents, a gable vent and a shutter exhaust fan, something different or nothing at all? I just want to do this right and make sure my attic has sufficient ventilation once it’s enclosed. I hope to hear back from you. Thanks! 

Last questions. I found a 36×36 square gable vent that has a NFVA of 585. I need 576 on both sides of my building so this vent should be sufficient, correct? Also, with me using the 1/300 ventilation rule the gable vent company who has this vent recommended using a vapor barrier in the attic too. I believe he said that it needs to be no more than 1 perm and to install it on the warm side of the attic. He said this is needed because I’m not using the 1/150 rule. He said if I have 16 sq ft on ventilation instead of 8 I wouldn’t need a vapor barrier. That’s not really an option though. That many gable vents wouldn’t look good. So what do you think? Do I really need a vapor barrier using the 1/300 rule? My roof panels have a felt-like material on the underside of them that I believe is called “drip x”. I was under the impression that this was a vapor barrier and when warm air rises and hits those cold roof panels the “drip x” keeps it from condensing. Do I really need a vapor barrier along the warm side of the attic too? That sounds like overkill to me but I want to do it right too. The plan is to fully finish the inside of my outbuilding eventually with a ceiling that will be white ribbed panels with a r-38 blown in fiberglass. I only plan on heating the building to about 55-60 degrees and that’s only if I’m out there working. The thermostat will be set to 45-50 if I’m not out there. Also, this outbuilding doesn’t currently have air conditioning but I may consider adding it down the road. You’ve been a big help so far. Thank you and I look forward to your response. “

Mike the Pole Barn Guru responds:

As long as your four square feet (576 square inches) of NFVA (Net Free Ventilation Area) is located in the upper half of each gable endwall, your formula is correct and should provide sufficient ventilation. Actual vent size is not the same as the NFVA – so look closely before investing in any particular vent.

A vapor barrier would only be needed if you have over 8000 heating degree days. One of those vents on each end should do the trick. 

You can look up your heating degree days here: https://www.huduser.gov/portal/resources/UtilityModel/hdd.html

How to Best Use Roof Steel Already Owned

How it is people end up owning steel roofing (or siding) when they do not have a structure to put it on has always been somewhat of a mystery to me.

Reader TIM in IRON RIVER writes:

“Hoping to build 40’x56′ post frame structure with 2′ overhang and 4/12 pitch using steel roofing I have on hand. That said it looks like I need roof lengths of 23′-1 1/4″ long to get that 2′ overhang. I have plenty of 20′-8″ and 2′ steel roofing and when combined with overlap I’ll be short (20′-8″ + 2′ minus 4″ overlap = 22′-4″) approximately a 9″ overhang. We do get plenty of rain here so the more overhang the better. For a 4/12 pitch how much overlap should I have for two adjoining roof pieces? Is there a vent gap at peak and if so how big of gap? Would 9″ overhang be sufficient for a rainy area to maintain building longevity? I guess I could go shorter on the 40′ width in order to use one single roof piece and to attain 2′ overhang. Your thoughts please.”

Mike the Pole Barn Guru responds:

If at all possible I try to avoid steel panels overlapping steel panels along their run.

Why?

Because all panels have been run through an identical set of dies, they are not designed with ‘outer’ panels having slightly larger ribs in order to accommodate a smooth lap transition. From experience, this overlap will attempt to “grow” on you as you go along your roof.

Most steel manufacturers recommend a minimum end lap of 12 inches. All overlaps should be made so as to center on a roof purlin.  A 3/32″ x 1/2″ butyl endlap sealant should be applied on the bottom panel just below the centerline of the purlin where lap will occur. Due to the probability of panels not lying smoothly, sidelap sealants may also be needed.

Roof panels from each side should be held down from the peak of the roof by several inches (generally no greater than four with standard ridge caps) to allow for ventilation.

With all of this said, if it fits on your property, you should consider going to say 36′ x 60′ (or 72′), with 18″ overhangs to best utilize material you have and eliminate any overlapping splices. With 18″ overhangs on ends also, three foot width panels will lay out nicely without having to rip a panel when getting to building ends. Either of these building lengths will work out well for framing material usage with double trusses aligned with columns every 12 feet.

Proper Ventilation, Condensation Control, and Post Treatment

This week the Pole Barn Guru answers reader questions about ventilation, how to control condensation on fifteen year old building, and best practices for treated posts in ground or on specialty brackets.

DEAR POLE BARN GURU: I have a barn that doesn’t have soffit vents but it does have a ridge vent. I installed reflective insulation which seems to have dropped the temperature quite a bit. I also have a gable powered fan that does 2000 CFM. However it is about 8 to 10 feet lower than the ridge vent. Are these two things fighting each other do you think or should I take a pipe and vent it up to my ridge vent and to my fan to take the hot air out from the top or should I turn my gable fan off completely.
I could always try to install some soffit vents as well. KEN in GREENVILLE

DEAR KEN: Your ridge vent is a natural air exhaust point, as warm air will rise and exit through it. Any vents lower in your building should be air intakes (whether gable or soffit vents) and ratio of net free ventilation area between the two should be roughly equal (intake can be up to 10% greater area than exhaust, but should not be greater).

 

DEAR POLE BARN GURU: I have a 30x56x10 Menards package with the inside finished off with drywall built 15 years ago. The roof was installed without any condensation control to the underside of the steel. The amount of condensation this past year created truss heave. All ceiling penetration’s are sealed and fiberglass blow in was installed to a r49 rating. what would be the most effective way to eliminate our condensation issue? Thank you for your time and knowledge. LOUIE in AMBOY

DEAR LOUIE: Drives me absolutely bonkers when providers or builders make no true efforts to advise customers on perils of condensation and how to prevent it. So easily, and inexpensively, done at time of construction.

Have two inches of closed cell spray foam applied to the underside of your roof steel. Make sure your dead attic space is adequately vented, ideally with soffit vents and ridge vent, or (if no sidewall overhangs) gable vents and ridge vent. If you do not have a vapor barrier under your concrete slab, apply a high quality sealer to it.

DEAR POLE BARN GURU: What are the pro’s and con’s for 6″x6″ posts to be set on a drilled whole with footer at the base then back filled VS drilled whole with footer poured to grade and using CBS/CBSQ column bases that are submerged into the footer while pouring so the 6″x6″ can be above grade.

Column bases are made by Simpson Strong-Tie on page 76 and 77 they also come in stainless steel. I attached the Simpson booklet for you to see the Column bases, I’m looking to build a 40’x40’x14′ pole barn with gable roof, one man door, 16′ wide x 13′ high insulated garage door, and a cement floor. I live in North East Ohio so I get a far amount of snow load.

Kind regards, DENNIS in CHESTERLAND

DEAR DENNIS: Properly pressure preservative treated columns, embedded in ground are unlikely to decay within lifetimes of anyone alive on our planet today https://www.hansenpolebuildings.com/2020/09/pressure-treated-post-frame-building-poles-rot/.

Simpson brackets you reference are not designed to withstand moment (bending) loads, just uplift and downward (gravity) loads. If your concern is properly pressure preservative treated columns will decay prematurely and do not want wood in ground, we can furnish your building kit package with Code compliant brackets and properly engineer concrete piers. Bracket mounting will increase your investment, somewhat, however if it results in your sleeping better at night, then they are well worth it.

 

Roof Insulation, Pole Barn Houses, and Adding Heat

Today the Pole Barn Guru tackles reader questions about the best method of insulating a building with no plans for a ceiling, planning a pole barn house, and adding heat to a completed post frame building.

DEAR POLE BARN GURU: I am insulating my 30×50 pole barn that is wrapped with Tyvek outside the purlins and I will use faced batt insulation on the 10ft walls. I will have it heated in the winter with the gable vents and cupola closed when working, but will not cool it in summer months. My question is what is the best method to insulate the roof as I don’t plan to add a ceiling? Currently, there is a radiant barrier on top of the roof purlins directly below the metal, and the only venting is the cupola and two gable vents. ERIK in FESTUS

DEAR ERIK: Without a ceiling I would have recommended two inches of closed cell spray foam applied directly to your roof steel – except you have a radiant reflective barrier in place (not a best thing to spray foam to). This method also means it would be nice and toasty between your trusses, but not so much in your working area.

Provided your roof trusses are capable of supporting weight of a steel liner panel ceiling, I would encourage you to consider it as an option, then blow fiberglass insulation in above liner panels. Alternatively, you could use lathe, wire mesh, or other means across bottom of trusses and place unfaced batt insulation on top.

 

DEAR POLE BARN GURU: I would like to know about building a pole barn house. 3 bed 1.5 to 2 bathroom. If I order from you do I build it of you? How much do they cost? DAVID in KALKASKA

DEAR DAVID: This article should get you started https://www.hansenpolebuildings.com/2021/02/a-shortlist-for-smooth-barndominium-sailing/

 

DEAR POLE BARN GURU: Heating an unvented barn? I have a 52×70 Hansen pole barn. I have decided I would like to heat the space. I have sealed the concrete and have spray foamed the walls with 2.5″ closed cell and blocked the soffit vents while doing this. I will be using a combo of a waste oil furnace and a wood stove to heat the space. My question is can I block off the gable vents instead of putting in a ceiling? Will I have moisture issues if I do this? I did use the foil insulation between the roof sheeting and the purlins that came with the package. Thanks. MARSHALL in CAMANO ISLAND

DEAR MARSHALL: Please keep in mind the Reflective Radiant Barrier under your roof steel is a thermal break designed to control condensation from occurring on underside of your roof steel, it is not insulation and has a R value of roughly one (R = 1). If you block off all vents, you may need to mechanically dehumidify your space in order to reduce moisture inside. Alternatively, should you install a ceiling and insulate above it, you would need to appropriately vent dead attic space to prevent roof system mold and mildew.

 

 

 

 

Insulation Option, Condensation Control, and Plans Only?

Today’s Pole Barn Guru answers reader questions about adding a styrofoam insulation board to help keep a pole barn warm, how to best prevent condensation, and if one can purchase plans only instead of the complete kit.

DEAR POLE BARN GURU: I recently built a pole barn, I’m in Ohio. I put in a 15000w electric heater, it does an ok job as long as it’s not 20 degrees out. My question is, can I use styrofoam insulation board that is 1″ think for insulation on the trusses? I have a condensation layer on the roof metal. I’d like to start somewhere and I thought this would be least expensive. Thanks. TERRY in CARROLL

DEAR TERRY: If “on the trusses” is in reference to across truss bottom chords, chances are good your trusses can support their weight if your insulation board is polyisocyanurate. Polyiso weighs in at roughly 0.25 pounds per square foot per inch of thickness. An inch of polyiso provides an in service R value of roughly 5.6. Polyiso insulation may need to be fire or flame spread protected, by Building Code – you will want to consult with your local Building Official, prior to moving forward. Adequate ventilation must be provided for your dead attic space (read more about ventilation requirements here: https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/)

DEAR POLE BARN GURU: I’m working on building a 30×40′ post frame building for storage/ garage and workshop and I live in Kansas so it’s cold in the winter and humid in the summer so I have concerns about condensation. I’ve looked into the single and double bubble foil insulation products and just the foil sheets for thermal/ condensation and the condensation blankets.

I plan to eventually insulate the walls and heat with a wood burning stove and just open the garage doors and turn on a fan in the summer. When I pour my slab I have 10mil vapor barrier that will go down on the ground.

What would be my best budget option to help control condensation and insulate some? JOEY in ANDOVER

DEAR JOEY: I will do my best to balance ‘best’ and ‘budget’.

Kudos for use of a under slab vapor barrier thicker than 6mil. My typical recommendation is 15mil, but 10 is certainly a step up. Make certain overlaps are well sealed and run it up inside and onto top of your pressure preservative treated splash planks (bottom girt).

Walls – use a well-sealed Weather Resistant Barrier (WRB) between framing and steel siding. Read more about WRBs here – https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/. Frame walls with commercial bookshelf girts (https://www.hansenpolebuildings.com/2011/09/commercial-girts-what-are-they/). Install unfaced fiberglass batt insulation between girts, with a well-sealed 6mil clear visqueen vapor barrier on inside.

Roof – order roof steel with an Integral Condensation Control factory applied (https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/). Roof trusses should be ordered with raised heels two inches greater in height than thickness of blown in fiberglass attic insulation (https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/) and attic adequately ventilated with vented soffit panels at eaves and a vented ridge.

DEAR POLE BARN GURU: Good Morning, Can I just order the plans for a pole barn instead of the full building kit? TANNER in BOWLING GREEN

DEAR TANNER: Thank you for your inquiry.

Engineer sealed pole barnHansen Pole Buildings are carefully designed and engineered to exacting and stringent standards. Included with these structural design solutions are some components an average individual cannot just go buy off a shelf at your local lumber dealer or big box store. Due to liability issues with materials specified on plans not being able to be readily acquired by general populace members, our third-party engineers are unable and unwilling to put their seals and signatures on plans where we are not providing components. Even if they were to do so (and you could find parts as specified) we have so much buying power, we are able to provide materials at a price level competitive to anything you would be able to acquire on your own.

 

Gable Fan, Clay Soils, and Condensation Issues

This week the Pole Barn Guru answers reader questions about use of a gable fan to prevent condensation, building with posts in clay soils, and addressing condensation issues in a three-stall garage.

DEAR POLE BARN GURU: I have been reading some post on your site about gable vents. I have a 40×80 building with spray foam on the bottom of the roof, which is sheeted with plywood. The walls have rigid foam and fiberglass. Question is, would an electric gable fan help or hurt condensation in the building, and is it even necessary. Much of the building will become heated and cooled living space. STEVE in SOMERSET

DEAR STEVE: It is very possible a humidity controlled electric fan would assist in reducing condensation, however before moving forward with it, I would recommend you consult with your HVAC provider, as a properly designed heating and cooling system can be set up to provide adequate air exchanges and control humidity.

 

DEAR POLE BARN GURU: I have heavy clay soil that does not drain. If I put posts in ground the bottom 2 feet will be soaked most of the year. Should I use concrete piers or will proper treated post be ok? MATT in MORRISTOWN

DEAR MATT: Having personally built a post frame combination garage/shop/mother-in-law apartment at our son Jake’s then home near Maryville, I feel your pain when it comes to Tennessee clay soil. Properly pressure preservative treated columns are not negatively affected by ground water, however you have other factors to consider before moving ahead with your build. You’ll want to read these articles discussing them: https://www.hansenpolebuildings.com/2019/06/post-frame-construction-on-clay-soils/ and https://www.hansenpolebuildings.com/2020/07/barndominium-on-expansive-soils/.

 

DEAR POLE BARN GURU: Hello, We are building a 3 garage pole barn and would like to know if you suggest the following:
A. Can you spray foam insulation to house wrap and do you leave the paper under mullions if removing the paper?
B. We have sweating on our house wrap and in our bay that will be mostly finished we put insulation boards which had paper on both sides and now will have to remove that side siding to remove it.
C. Our bay 3 floor is just stone, the others are concrete. We didn’t put a vapor barrier plastic under stone, so until spring when we remove stone and do this we were thinking of laying a tarp tight on stone to hold back any moisture into the rooms for humidity and condensation. What do you suggest? LAURIE in NEW YOUR

DEAR LAURIE: While there are some installers who will spray foam to a WRB (Weather Resistant Barrier aka house wrap), we do not recommend it https://www.hansenpolebuildings.com/2020/04/spray-foam-insulation-3/

vented-closure-stripIf you are getting condensation inside of your WRB it is due to excess moisture in your building. You need to eliminate or minimize sources of water vapor (seal any concrete slabs-on-grade if a well-sealed vapor barrier was not installed beneath). Proper ventilation from eave to ridge will also help to alleviate this challenge.

Provided you can well-seal a tarp, it is certainly a better option than just leaving raw stone exposed.

 

Our Builder Has a Few Questions

Our Builder Has a Few Questions

Not a surprising statement, as few stick frame (stud wall) builders are willing to learn a new structural system, and few post frame builders have actually erected barndominiums or shouses (shop/houses).

I was a first group member (although willing to learn) and frankly lost my posterior financially erecting my first ‘pole barn’ because I had such a difficult time wrapping my head around left-to-right rather than up-and-down. I got my head on straight for building my second one and actually made $100 an hour back in 1980 erecting it!

For this second group, post frame home building takes in an entire new toolbox of concepts. Energy efficiency and ventilation concerns must be addressed, as well as a different set of efficiencies of material use. It is no longer just a ‘pole barn’  and requires a far greater degree of precision – it isn’t necessarily more difficult, but does take more thought.

Reader BRIAN in PETOSKEY writes:

Hi Mindi and Mike!

We’re really excited that we’re closing in on a final exterior design and starting to focus on the ‘fun stuff’ inside.

We shared the renderings and quote with our builder to keep him in the loop and he had some questions I wanted to share with you.

I’ve read your blogs and understand the argument for the truss arrangement that Hansen prefers. Trust me, I see the logic. That being said, he’s definitely one of those ‘trusses on 2′ centers’ kind of guys.

I explained all of the blog-based talking points on why it’s ‘better’. He was concerned that the material cost may be less, but the labor time would be significantly more to fill in between those spans with 2x10s, etc.

Furthermore, he usually covers the roof in OSB sheathing before putting on the metal. Is that included in this quote? Or is that something extra? He’s concerned about the logistics of applying the OSB with such wide spans between trusses. And in a similar vein, with drywall going on the full underside of all scissor trusses, he’s concerned about the additional lumber and labor needs to provide adequate hangers for sheetrock, etc.

And on top of that, he’s concerned about the lack of ventilation in the roof. I was under the impression that spray foam right onto the underside of the OSB for the entire roof was a best practice. He’s thinking we need baffles or something to allow airflow so as not to compromise the OSB over time.

So basically, a lot of questions on the construction logistics as it pertains to trusses and roof. Why not just run 31 scissor trusses on 24″ centers the length of the building and call it good? And how best to handle ventilation.

One comment he offered several times was that he understands the logic behind this construction style for a garage or storage building, but for a home with heat and sheetrock, etc. he thought this would be creating some obstacles for us.

If this is best answered via email, I’m happy to run middleman or add him as a CC on the answers. He also asked if Mike or someone from Hansen would be willing to talk to him on the phone? He’s open to the process, but wants to make sure he understands exactly what the construction process looks like. He said he would love to see a sample cross section or blueprint, but we both understand those are kept secret until we pay. He wants to wrap his head around it all.

One other concern was about wall framing. Some of the videos show horizontal studs as opposed to vertical. He wasn’t sure if that was always the case or if that is specific instances. Again, he’s a vertical stud kind of guy, but wants to understand if he can change that orientation or if it’s non-negotiable.

When it comes to truss space/between truss framing/wall framing, he’s definitely concerned about drywall logistics, OSB logistics (or not), moisture, and labor. And I want to make sure he feels heard and informed before we dump these plans and materials on his plate. I see both sides, but at the end of the day, he’s our builder and I need him to be fully on board before pulling the trigger. Could you help? I’m sure I’m not the first person with this quandary but I’ve also used enough pole barn builders in our area to know that he’s our best option for this project.

Thank you so much.

I see this dialogue as a parallel conversation to the design process. We’re forging ahead with design and working on our window and door placements this weekend.

Thank you!
Brian


Please tune in tomorrow for answers to Brian’s builder’s questions.

11 Reasons Why Barndominium Crawl Space Encapsulation is Important

11 Reasons Why Barndominium Crawl Space Encapsulation is Important

Today’s Guest Contributor is Joseph Bryson. Joseph was born in Alberta, raised in NYC and is living in New Zealand. He has been working in 4 different industries and helped numerous businesses grow. Now, he is focused on writing as his next career from home and lives a peaceful life with his family and a whole pack of dogs.

No matter what kind of a barndominium you will have, if there is a crawl space present then it can potentially cause you a whole host of problems. People tend not to realize this because they don’t think too much about crawl spaces. 

Like it’s not a place people generally venture to in their own homes. It’s just down there beneath your elevated wood floor, out of sight and out of mind. And so various issues can arise in your house you don’t know how to fix because you don’t realize they’re originating in your crawl space. 

In a post-frame building, crawl spaces are set up a little bit different. Instead of having a perimeter of concrete and a concrete slab, it is instead a wooden framework on short pressure preservative treated timber or glu-laminated columns.

It’s a style of crawl space allowing for much better access to plumbing, ventilation ducts and electrical wiring, but without a concrete slab. It also makes it somewhat more susceptible to some of these problems. 

This leads us to crawl space encapsulation creating an unvented crawl space. A process involving installing a vapor barrier in your crawl space to cover ground, walls and seal up all vents and seams. Air is then conditioned using a humidifier or HVAC system.

International Residential Code (IRC) R408.3 addresses unvented crawl spaces. Exposed earth is covered with a continuous Class I vapor retarder. Vapor retarder joints shall overlap at least six inches and be sealed or taped. In post frame buildings, this vapor retarder must extend up perimeter walls to floor level and be attached and sealed to floor. One of four possible options outlined in IRC R408.3(2) must also be met.

Let’s have a look at what issues a crawl space encapsulation will help to prevent and why it’s so beneficial:

  1.   Controls Pests

One very important thing you’ll be doing by sealing up all openings is removing access to your crawl space for a wide variety of pests. You can get mice, rats, cockroaches, racoons and even birds have been known to find their way into crawl spaces.

Once pests find their way in, it can be a nightmare getting them out but an encapsulated crawl space removes a primary entry point for pests so you would be reducing possibilities significantly.

Roaches can be disastrous for a wooden framework and so you should be very serious about keeping them out of your crawl space and your home in general.

  1.   Improves Air Quality

Because air coming up through your crawl space will be going through HVAC or a humidifier, you can rest assured it will be much higher quality than if it was just blowing in unfiltered. A crawl space is a hot bed for low quality air, but not if it’s encapsulated.

  1.   Allows for Better Energy Efficiency

One thing you will probably notice after encapsulation is your energy bills will be lower. Your heating and air conditioning won’t have to struggle against crawl space damp air, meaning they’ll be doing less work.

And this will of course result in you having to spend less on utilities. While encapsulation might cost a bit, it is Code required and will be financially beneficial over time.

  1.   Keeps Floors Warm

As we just mentioned, the normal state for a crawl space is to be full of damp air. It’s exposed to elements and especially during winter months, this just means there’s consistent moisture and low temperatures blowing through.

All of this is prevented with encapsulation meaning the only thing rising from below will be heat. And while it won’t necessarily be equivalent to under floor heating as such, it will make floors more warm and comfortable to walk on, especially in a post-frame home where there isn’t concrete separating heat from floors.

  1.   Prevents Mold

Mold is very problematic. For some people it’s just an irritant causing things like coughing, sneezing and sore throats, but it can also be toxic if left to grow for too long. And for anyone with a compromised immune system or who suffers from asthma, it’s dangerous.

Mold and mildew are further consequences of dampness and moisture retention and most crawl spaces are full of it. It’s much more likely to build up on wood than it is on concrete meaning this is more common in wood frame structures.

  1.   Improves Storage

Not everyone opts for using their crawl space for storage, even after it’s been encapsulated, but  it can be done. If your encapsulation is neat, you should definitely have some room down there to store a few boxes.

If you did this with an unencapsulated crawl space, then anything you store could be potentially damaged by moisture or mold. So it’s basically a really safe storage space once encapsulated.

  1.   Prevents Flooding

I’ll start this point by saying crawl space encapsulation doesn’t necessarily prevent floods entirely, but it can help in a lot of cases. Excess rainwater and runoff can build up down below and can result in flooding, but not if everything is sealed and blocked up.

Flooding takes a much greater toll on wood than it does concrete and although your post-frame home will be sturdy by design, too much water over time could do some serious damage.

  1.   Protects Structural Integrity

If left for long periods of time without intervention, moisture and mold will slowly eat away at untreated wood under your home. This will eventually destroy structural integrity and you won’t have any idea it’s happening because it takes so long.

Just another reason why you should be slowing down, or entirely stopping mold growth and retention of moisture.

  1.   Keeps Allergens at Bay

Spread of allergens is primarily caused by moisture and dust. We’ve discussed to death how moisture is controlled by encapsulation, but because air coming through is unfiltered, dust shouldn’t be a problem either so if you’re prone to allergies you will benefit.

  1. Can be Done Without Professional Help

Key word here is ‘can’. Crawl space encapsulation can be done without professional help. Before hiring a professional it’s worth looking into how you would do it yourself.  

If you have an interest in DIY and are particularly adept at this type of handiwork, you could for sure give this a try. Again, not everyone will be up to this task, but if you are then it will save a lot of money.

  1. Enhances Longevity of Your Home

With all of these different things considered, it’s clear crawl space encapsulation will help make sure your barndominium is in livable condition for a long, long time. Every issue we’ve discussed here will gradually build up until it becomes potentially disastrous.

Crawl space encapsulation is a big job, but fairly easily accomplished DIY.

Vapor Barrier for a Ceiling

Reader GEORGE in LOUISVILLE writes:

“I am looking to install tin on the ceiling of my 54 X 75 pole shed. I was wondering if 6 mil plastic sheeting with all seams taped would work for a vapor barrier? My concern is not to have it rain in my building after the tin is up and the heat is on.”

Mike the Pole Barn Guru:

Well George, this answer is not going to be nearly as simple as your question.

Prevention of internal rain (condensation) is going to be a function of several aspects.

#1 Controlling source – if there is not a well-sealed vapor barrier under your concrete slab on grade, you should be planning on two coats of a good sealant for it. If you do not know if there is a vapor barrier under it or not, leave a wrench on it overnight. Next day, pick the wrench up and if there is a dark place on the floor surface where the wrench was, you have no under slab vapor barrier.

#2 Source of heat – some heat sources add significant amounts of water vapor into your internal air (propane being a prime offender). Know what you are getting into before it becomes a challenge you do not want.

#3 How are you currently controlling condensation? If your building has a thermal break between purlins and steel roof – excellent. If not, your best solution is going to be two inches of closed cell spray foam applied to the underside of roof steel. This is not an inexpensive solution, but it is more practical than removing roofing, adding a thermal break, and reapplying roofing (plus roofing never goes back on as well as it was originally installed). Plan on $4000 to $4500 for closed cell spray foam.

vented-closure-strip#4 Ventilation – you are going to create a dead attic space above an insulated ceiling. If it is not adequately vented you are going to have problems. Best combination is vented eaves and ridge. Your building will require at least 1944 square inches of net free ventilation area (NFVA), distributed equally between eave and ridge. If this is not possible (building has no sidewall overhangs), then your choice is limited to gable vents and it will take many of them to provide adequate NFVA.

#5 You are in Climate Zone 5. This means a Class I or II vapor retarder is required for the interior side of framed walls. This could be 6 mil polyethylene (Visqueen) or Kraft-faced fiberglass batt insulation. For your ceiling a plastic vapor barrier should only be installed in vented attics in climates with more than 8,000 heating degree days. In Nebraska, heating degree days for a normal year is 6322.

Gable Vents, Plasti-Sleeves for Posts, and Cost per Square Foot

This Monday’s questions are addressing the issues of ventilation with gable vents, the use of plasti-sleeves to protect posts, and the cost per square foot of a post frame home.

DEAR POLE BARN GURU: My dad has a 40 x 60 pole building. It has 18″ eaves but the soffits are non vented. The building also has no ridge vent. He has not had any moisture issues but is looking to add gable vents as a means to get rid of fumes from occasional painting and or welding. The building is open with no closed attic space. Is there any issues with adding gable vents for this purpose? BILL in COEUR d’ALENE

DEAR BILL: There should be no structural issues with adding gable vents, although they may not cure your dad’s fume issues. It may be prudent to add a powered exhaust fan.

 

DEAR POLE BARN GURU: How to protect the wooden poles when pouring cement floors—doesn’t this deteriorate the poles? Thanks. LINDA in BEAR CREEK

DEAR LINDA: Building Codes actually REQUIRE lumber in contact with concrete to be pressure preservative treated. There is no documented research to prove concrete (or one of its components – cement) deteriorates properly pressure preservative treated columns.

If you are overly concerned or unsure about this, we can provide Plasti-sleeves with your engineered post frame building package. https://www.hansenpolebuildings.com/2012/04/plasti-sleeves/

 

About Hansen BuildingsDEAR POLE BARN GURU: What is the cost per square foot on building a Barn Home? If this isn’t feasible, then what is the cost for finishing a purchased Barn Home Kit? JOEL in COLUMBUS

DEAR JOEL: Barn homes (aka barndominiums or post frame homes) can have finished costs ranging from $50 to hundreds of dollars per square foot depending upon your individual taste and how much work you are willing to do yourself. This article will assist you in formulating a budget: https://www.hansenpolebuildings.com/2019/07/how-much-will-my-barndominium-cost/

 

 

Two Story House, Car Storage, and a Post Frame Basement

Today’s Pole Barn Guru answers questions about building a two story pole barn house, condensation in a car storage building, and how to build a post frame house with a concrete basement.

DEAR POLE BARN GURU: We are wanting to build a 2 story pole barn house, it will have an upstairs loft. Would the standard pole footings support 2 stories, or would it need a concrete footing foundation, like what is used in a stick built home? NICK in FAIRBURY

DEAR NICK: As long as you construct your building from engineered plans, your engineer will have properly sized your building’s “standard pole footings” to be able to adequately distribute weight across your soil. We live in a multistory post frame (pole barn) shouse with a 44 foot overall height and it has typical embedded footings and has performed admirably.

 

DEAR POLE BARN GURU: I have a 20′ x 40′ closed in pole barn that I use for storing cars, it has a ridge vent & the soffits & eaves are open to the weather, how can I keep the cars from sweating? BILL in EATONTON

DEAR BILL: You will need to reduce humidity in your building.

Use a good sealant on top of your concrete slab.
Install 2x blocking snugly between purlins overhanging endwalls (directly above end trusses).
Spray 2″ of closed cell insulation on inside of all wall and roof metal (leave eaves and ridge open to provide attic intake and exhaust ventilation).
Install a tightly sealed ceiling (no air gaps to attic).

Add controlled mechanical ventilation.

DEAR POLE BARN GURU: We are potentially interested in building a pole barn home and have a few questions. Cost different from a traditional home build isn’t the major concern from us, we love the open rustic feel of a barn home. We would like to include a basement with the home. I read some previous blog posts and it seems like this is possible, however was wondering do the sidewalls of the basement need to be inset from the sides where the posts go into the ground?

If the walls are inset, is it possible to have a basement with egress windows below the pole barn home? RYAN in OSWEGO

DEAR RYAN: We can have your building engineered so columns will mount directly to top of your concrete basement walls. Makes everything far easier.

 

My Barndominium Windows Are Leaking

Common questions we hear from barndominium, shouse (shop/house) and post frame home owners are, “Why are my new windows leaking?” or “Why do I have condensation inside of my windows?” In fact, many new barndominium owners think their windows are defective and need to be replaced in an effort to cure this problem. To answer these questions, let’s review what causes window condensation.

Condensation is visible evidence of excess air moisture. It may appear as water, frost, or ice on window or door surfaces. This occurs more frequently during winter months because of extreme differences between inside and outside air temperatures. Warmer air holds more water meaning air in any given room center will hold more water than air adjacent to window or exterior door walls, since this area is always cooler. When warm, moisture laden air moves toward cooler window or door walls, it becomes cooler and cannot hold as much moisture as it held when it was warmer. This moisture is dropped and appears as water on glass and frames of windows and doors.
Windows do not cause condensation, they just happen to be where moisture is most visible. Condensation is a sign of excess moisture in barndominiums. This can be caused by temporary conditions such as:
Building materials contain a great deal of moisture. As soon as heat is turned on, this moisture will flow out into the air and settle on door and window glass. This will usually disappear following first heating season. During humid summers, houses absorb moisture. This will be apparent during the first few weeks of heating and then should dry out. Sharp, quick, and sudden drops in temperature especially during the heating season will create temporary condensation problems.

Condensation can also be caused by more permanent conditions:
Insufficient attic ventilation and/or soffit ventilation traps moisture in barndominiums. Having sufficient soffit vents to allow adequate air flow in and ridge vents for exhaust will allow moisture and humidity to escape. Excessive humidity may be a result of poor ventilation but can also be a result of an imbalanced heating and air system or a need to add additional ventilation. Inadequate (or missing) vapor barriers under concrete slabs on grade. While Building Codes require a vapor barrier under any concrete slabs in heated buildings, it is all too often overlooked.

Controlled ventilation and elimination of excessive indoor moisture can keep humidity within bounds. Here are some suggestions to help reduce indoor moisture:
Turn off or set back furnace humidifiers until sweating (condensation) stops. Remove pots of water on radiators or kerosene heaters. Use exhaust fans or open windows slightly in kitchen, bathroom and laundry room during periods of high moisture production such as cooking, taking showers, washing and drying clothes. Clothes dryers must be vented outside. Do not hang clothes to dry indoors. Waterproof concrete floors. Make sure attic vents are unobstructed. Place all house plants in one sunny room where the door can be kept shut and avoid over watering. Opening windows slightly for a brief period of time will allow humid air to escape and drier air to enter. Use a properly sized dehumidifier, to reduce humidity.
Excessive indoor humidity and moisture are not a result of your windows. You should view the amount and severity of window condensation as a clue moisture damage may be taking place inside walls or ceiling cavities of your barndominium. This can lead to rotting wood, deteriorating insulation, and blistering paint.

Post Frame Indoor Swimming Pool Considerations

In my past life I lived with my family in Oregon’s Willamette Valley. Hot summer days filled with sunshine were about as rare as access to nearby lakes – close to zero. Having grown up spending summers at my maternal grandparents’ lake cabin, swimming has always been part of my life. A frequently told fable was my younger brother and I could swim before we could walk!

Given relatively mild winter weather, I opted to have an in-ground outdoor swimming pool added to our backyard. Many an hour was spent in this pool, prior to selling and moving back to my native Spokane area.

Reader CLINT in COLUMBUS writes:
“Saw a post about pole barn over an in ground pool.
Curious about moisture management? My pool builder says a lot of cost but won’t expand on it.”

Mike the Pole Barn Guru responds:
Indoor pools demand special monitoring for constant challenge of humidity control. Service pros shouldn’t be expected to maintain dehumidifiers, which are HVAC/R machines requiring EPA-certified technicians. Indoor pools can malfunction quickly, so a typical six-month or annual dehumidifier check-up by an HVAC/R service contractor isn’t enough to detect potentially damaging problems before they blossom.

An indoor pool is a unique synergy of four factors, degradation of any could result in building deterioration, air quality health problems and uncomfortable environmental conditions for users.

1. Building envelope: Indoor pools can experience issues related to construction techniques or building materials. For example, missing or breached vapor barriers can allow damaging condensation to accumulate inside walls. For post frame pool covers, I would recommend use of all pressure preservative treated lumber. Walls must have a totally sealed interior vapor barrier. Depending upon climate, adding a layer of two inch closed cell rigid insulation board to inside of framing reduces thermal transmission between interior and exterior and can be air sealed.

2. Ventilation: Supply air ducts and vents must fully cover exterior windows with conditioned air to avoid condensation. System must move air down to breathing zone for good air quality.

3. Dehumidification: Most indoor pool spaces have a dehumidifier to maintain 50- to 60 percent relative humidity and cool or heat air to a set point temperature. Without it, the space probably depends on outdoor air and exhaust.

4. Water chemistry: Imbalanced chemistry results in buildup of respiratory-affecting chloramines and potentially causing surfaces to corrode.

Most modern dehumidifiers are complete HVAC machines heating or cooling space and use compressor heat recovery to heat pool water.

So space and water temperatures, and relative humidity are key checkpoints. These parameters are displayed on a microprocessor’s LED keypad readout and in many cases can be accessed remotely. A good rule of thumb is to keep a two-degree difference between space (higher) and water (lower) temperatures. A common indoor pool set point is 84°F space, 82°F water temperature and a 60 percent relative humidity. Lowering space temperature by even two degrees increases humidity load by 35 percent, which could surpass a dehumidifier’s capacity.

Many dehumidifier LED keypads have red warning lights to indicate an operation stoppage or problems, which only an HVAC/R technician can repair. This readout menu can be scrolled to find a cause.

No water should leak from inlets or outlets of dehumidifiers with a pool water heating feature. On the other hand, hundreds of pool water heating models have been errantly left unconnected to the pool’s circulation systems. Owners should know water heating connection to a dehumidifier could save hundreds of dollars on utility bills annually.

An overflowing condensate drain pan (or watermark evidence) could point to a potentially damaging drain line blockage.

Condensation on exterior walls and ceilings should not occur. Window and skylight condensation indicates the glass is not covered with warm dehumidified supply air and its temperature has dropped below the dew point.

Premature corrosion on door hardware or room surfaces could indicate a problem.
Indoor pools must operate with a negative building pressure: Approximately 10 percent more air volume should be exhausted than introduced. A malfunctioning exhaust fan or ventilation design can result in positive pressure and push pool air and odors into connected living quarters. Positive pressurization also can push moisture into poorly sealed voids inside walls and above ceilings where it can produce mold and deteriorate the building. Indoor pool building pressure can be easily checked by slightly opening a door and seeing if air is being pulled in (negative) or pushed out (positive).

Dehumidifier supply air blowers generally run 24/7 to offset pool evaporation, so monthly or bi-monthly air-filter replacements may be needed. If the blower isn’t running, there’s something amiss.

Dehumidifier compressors run at least 10 minutes at a time. Hearing compressor short-cycle off and on several times within a minute or two warrants an HVAC/R service contractor’s attention. Very noisy ductwork, such as drum head effects and extreme vibrations, could point to a poor ventilation design. Unusual sounds, such as fan belts squealing or worn out motor or blower bearings, also require an HVAC/R contractor.

A final note: Suggesting owners call their dehumidifier maker rather than an HVAC/R contractor usually won’t help because they rarely perform repairs. However, a factory tech’s review of data can help HVAC/R service pros troubleshoot issues.

General Material Storage for Barndominiums

General Material Storage

I have recently signed up to join several barndominium groups on Facebook. If you are unfamiliar with this term, here is a detailed explanation: https://www.hansenpolebuildings.com/2016/04/the-rise-of-the-barndominium/.

Overnight I have had an ‘ah-ha’ moment where a light bulb turned on and I decided to take a plunge. I am going to write at least one book on post frame barndominiums. I posted my mission in these groups – looking for advice on what chapters would prove to be most meaningful. And I have received feedback. Lots and lots of feedback.

One of my fellow group members has suggested a chapter on how to store post frame building materials once received. In looking at how chapters appear to be laying out so far, it appears this subject may not get covered until Volume Two of my series. Of course this gives me an ability to have commercials like – “Call in next 10 minutes and we will throw in Volume Two at no charge – you just pay for shipping and handling!”

This happens to be a subject covered at length in Hansen Pole Buildings’ Construction Manual, so rather than having to wait for book publication, here is how to safely store materials.

General Material Storage

Store off ground any materials not being used within construction’s first few days (or more than a week after delivery) and cover with a tarp.

  • Some materials will be delivered in cartons. Avoid storing cartons in stacks.
  • Store cartons protected from falling materials or tools as they could damage enclosed contents.
  • Keep cartons dry. Best place to store cartons is indoors.
  • If cartons are stored outside, cover with a loose-fitting, light colored tarp, arranged to allow ventilation. This is critical, because some materials (especially vinyl) can be damaged if heat builds up around cartons.
  • Take special care storing any screws.
  • Store bolts, nuts and washers in a location where they will stay dry to avoid rust.
  • Windows, entry and overhead doors will frequently be delivered in cartons or crates. Store upright leaning against a solid surface such as a wall or workbench.

Stay tuned in for subsequent articles on how to safely store materials for your new building!

A Post Frame Addition, California Muster, and Ventilation

Today the Pole Barn Guru answers questions regarding a post frame addition, passing the “muster” of California’s building codes, and ventilation of attic space with spray foam.

DEAR POLE BARN GURU: Hi. We are wanting to attach a monitor style barn to an existing stick build for additional residential use. Is this tie-in possible? Thank you! TOM in KIRTLAND

DEAR TOM: It is very possible and will quite probably provide some real advantages, besides just affordability. Post frame buildings can be any variety of sidings, so it should be able to be structurally designed to tie pretty much up to any type of exiting building – provided existing building is structurally sound.

In order to do this right you have only a couple of choices – you can spend a lot of money on an architect and/or engineer who physically comes to your site (could be as high as 20% of project’s finished costs). Or you can provide lots of information to us on what we are attaching to, as well as conveying your expectations. We will do anything reasonable to assist you in not making a mistake you will regret always. If I thought anyone else could not just actually do it but also do it better than us, with you being able to construct yourself, I would in all honesty let you know.

Please dial 1(866)200-9657 and speak with a Hansen Pole Buildings’ Designer who can assist you to success.

 

DEAR POLE BARN GURU: Hi, Do you have any residential structures that have recently passed muster in southern California?

FYI I have a lot in Malibu but little $. I am wondering if I – and usually one helper – could construct a fire resistant home in this picky building code state.

Thanks, DAN in LOS ANGELES

DEAR DAN: We’ve been providing post frame building kits in Southern California areas of Very High Fire Hazard Severity Zones as well as Wildland-Urban Interface Fire Areas for years. Is does take a certain amount of patience, as plans almost always get kicked back at least once (relax – it is just a part of this process). Using steel roofing and siding, unvented steel soffits and wrapping any wood normally exposed with steel trims expedites approvals. If your property is located in a HOA (https://www.hansenpolebuildings.com/2012/11/homeowners-association/) be certain to talk with them sooner, rather than later.

As far as you and a helper – as long as you can and will read instructions and look at our third-party engineer’s highly detailed plans you should experience no real challenges. And, if you get stuck, we provide unlimited Technical Support at no extra charge.

A Hansen Pole Buildings’ Designer will be reaching out to you for more in depth discussions.

 

DEAR POLE BARN GURU: We bought a house kit from you all and have been very pleased. We had the roof deck, exterior walls and exterior walls of the crawl space spray foam insulated. They have essentially sealed the house. Will the lack of attic ventilation be an issue? HOLLY in TAYLORSVILLE

DEAR HOLLY: Thank you for your kind words, we would enjoy seeing any digital photos or video of your building during construction as well as completed.

If you spray foamed roof deck and have a dead attic space due to a flat level ceiling (we provided ceiling loaded trusses as well as ceiling joists) then you could experience condensation issues and potentially mold and/or mildew in attic, especially if attic is not made part of conditioned space (heated and/or cooled) with living area. If flat ceiling has also been insulated look out for trouble (keep a close eye on situation by doing visual attic inspections), as attic space could become quite a bit cooler than area below ceiling. Your spray foam contractor should have been talking with you about this prior to doing his or her application.

 

R Panel Gable Vents

R Panel Gable Vents

“R” steel roofing and siding panels are typically used on all steel buildings where larger spans occur between wall girts and roof purlins. With a three foot width net coverage, these panels have a 1-1/4 inch tall high rib every 12 inches with two low stiffener ribs between. R panels do not have a full underlapping (or purlin bearing) underlap. This lack of a purlin bearing underlap makes this product both less expensive (as it can be roll formed out of a narrower steel coil) and more difficult to install. Without careful placement at laps, panels tend to “walk” with one or both panel ends covering more or less than the necessary three feet.

Very few all steel buildings make provisions for ventilation. Rarely do they include sidewall eave overhangs, leaving no place for an eave air intake through a vented soffit.

So, how to vent?

Reader STEVE in PHOENIX writes: “Mike,
Hello. I’ve been researching venting options for an existing clearspan type red steel metal building and was directed to your snap in style gable vents for ribbed metal panels.  My building is covered with R panel metal siding…..the high ribs are 12″ on center (pic attached). I’ve been working with Justine on selection and pricing of your gable vents.  Will your vent panels work with this siding and if not, do you have a venting solution for this building? Thanks.”

My reply:

R panels typically have 1-1/4″ high ribs. I do not believe the snap ring vents will work with ribs higher than 3/4″ (Justine can confirm). If not, then you could use a standard gable vent with a J Channel surround. Just like snap ring applications, cut the hole in siding for the vent (make it 1/4″ taller and wider than the vent you will push through the hole). Cut J Channels to fit the vent, with interlocking and overlapping corners (just like a non-integrated J Channel window). Insert individual pieces of J Channel into the hole, joining corners as you go. Slide vent into J Channel “picture frame” using lots of caulking between vent and J Channel and at each of the J Channel corners.


Snap ring vinyl gable vents (https://www.hansenpolebuildings.com/2018/07/vinyl-gable-vents-for-pole-barns/) make installation a breeze and can quickly be installed in post frame buildings with steel siding with ribs no higher than ¾” . When designing your new post frame building discuss ventilation with your Hansen Pole Buildings’ Designer at (866)200-9657.

Pole Barn Guru Blog Review

This is the third year the Pole Barn Guru blog has been in competition for the Best Construction Blog. Last year this blog was second in the world, tying for first in quality, however losing the popular vote. Part of this process is a review of each blog by Mark Buckshon of Construction Marketing Ideas (www.ConstructionMarketingIdeas.com).

Below is Mr. Buckshon’s review:

Hansen Buildings’ Pole Barn Guru: Practical information about post frame (pole barn) structures

By Mark Buckshon

 –March 23, 2019

The Pole Barn Guru is currently leading in the 2018 Best Construction Blog’s popular vote and unless there is a surprising surge from supporters of another blog by the popular vote’s conclusion on March 31, this blog will probably earn the popular vote win status.

There are reasons for this support — the blog combines depth and focus as a “go to” resource for post frame (pole barn) buildings; and it doesn’t avoid the challenges with these low-cost structures, often used for outdoor storage and as rural outbuildings.

I’ve been reading some posts, for example, dealing with issues relating to condensation and insulation, some initiated by questions from outsiders — that is folks who have a pole barn structure not provided by Hansen.

Rather than brushing off these external inquiries with a: “Hey, that’s not my problem” attitude, this blog provides some practical answers, even as it indicates the issues probably wouldn’t have been problems if they had been considered in the initial design and purchase.

That educational aspect makes this blog truly worthy.

Consider, for example, this question in a recent blog post:

Hello! 

I have a pre-existing pole building that I am having a ton of trouble with. It is partitioned into two rooms, the back room is heated to around 50F. The attic space/loft space has a lot of condensation and I cannot seem to get this fixed. I have tried a lot of solutions, none of which have worked. I know that you build these types of buildings so I am hoping that you can recommend someone who might be able to come in and look at this issue and help me with a solution that works. I have no idea what to do next and I am a local business owner – my business is at a standstill right now until I can get this issue fixed. If you can recommend any general contractor, or anyone who might have expertise in pole buildings who I can contact I would greatly appreciate it. 

Thank you so much!”

The question is posed after a brief introduction:

Long time readers should be thoroughly drenched with solutions to condensation issues by now. As post frame construction has moved off farms and into suburbia, climate control has brought with it a plethora of condensation challenges.

So, what are the answers?

To control your condensation challenge you need to either remove warm moist air from inside your building, prevent this air from becoming in contact with surfaces at or below dew point, heat and/or ventilate. Here’s a brief summary, followed by solutions specific to your case: https://www.hansenpolebuildings.com/2019/02/how-to-reduce-condensation-in-post-frame-buildings/.

If you do not have some sort of thermal break below your pole building’s roof steel – two inches of closed cell spray foam should be applied. This process will be best done by a professional installer. Make certain to not block ventilation intake and exhaust points.

Unless you know for certain a vapor barrier was placed under your building’s concrete slab, seal the floor.  https://www.hansenpolebuildings.com/2019/02/how-to-properly-apply-post-frame-concrete-sealant/ 

and https://www.hansenpolebuildings.com/2018/11/siloxa-tek-8505-concrete-sealant/.

Vent any dead attic spaces. https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/.

Heating your building to a temperature above dew point will also solve this issue. Avoid heating with propane, as it adds moisture to the air.

Now in my opinion, that sort of detailed, practical advice shows how an effective, consistent and useful blog can provide real value to clients and potential customers alike (and serve a general community purpose, even for people who will never purchase a thing from Hansen.)

This value translates to search engine effectiveness and of course a reputation for knowledge and service. If you are thinking about purchasing a post frame structure, for example, I’m confident after reading through the relevant blog postings you’ll have the confidence to ask the right questions and share the site/usage observations to ensure that the structure serves its purpose and problems such as condensation or poor insulation don’t occur in the first place.

Issues with Condensation, Ground Water, and Overhead Door Size

Today the Pole Barn Guru answers questions about, condensation, ground Water, and an overhead door size.

DEAR POLE BARN GURU: Good morning,

My name is Brett and about to complete my Hansen Pole building.

I have having issues with condensation from my metal roof given the recent freezing weather. I do have a vapor barrier, but is not stopping the condensation that is now dripping into insulation and drywall.

Can you help me with this? Need a resolution quick

Thank you

BRETT in ARLINGTON

vented-closure-strip

DEAR BRETT: Your building’s dead attic space lacks adequate ventilation. You need to replace closed cell foam closures currently under ridge cap with Vented ones. Cut out any radiant reflective barrier between ridge purlins. Make sure to have an inch or more of free flowing air above insulation closest to sidewalls, so as not to impede air intake from building’s vented soffits..

 

DEAR POLE BARN GURU: Does it make sense to build a pole barn on standard frost walls where ground water and subsequent frost heaves are a problem? JOHN in LANESBORO

DEAR JOHN: Ground water is going to be an issue no matter what you do. Frost walls are going to be very costly (https://www.hansenpolebuildings.com/2018/11/foundations-2/), and you’d have to find a way to keep water out of your excavations long enough to set up forms and pour.

I’d be wanting to build up grade at building site for any type of construction.

For further reading – https://www.hansenpolebuildings.com/2013/11/sonotube/ and https://www.hansenpolebuildings.com/2011/11/site-preparation/.

 

DEAR POLE BARN GURU: Can I install an 18 ft wide garage door in a 20 ft wide pole barn? WILLIAM in TOWNSEND

DEAR WILLIAM: With proper structural design, probably. There are some downsides of this application, however. You will be extremely limited in your ability to place anything along building sidewalls. Care will need to be given in opening vehicle doors so as not to smash them against each other, or sidewalls.

For an 18 foot wide sectional overhead door, I normally recommend a building width of no less than 24 feet.

 

Hoop Shed Wall, Ventilation, and Pole Barn Footings

Today the Pole Barn Guru answers questions about adding a garage door wall to a hoop shed, ventilation with no sidewall overhangs, and how post frame buildings are “anchored” to the ground.

DEAR POLE BARN GURU: I would like to close the open 1/2 of the basketball court hoop shed with a pole building face.  I would like a large garage door in the center, fiberglass windows, and a door. Would you consider doing this project? JOHN in GILBERTSVILLE

DEAR JOHN: With no building behind to tie an endwall into, it would be structurally unrealistic and economically unaffordable to build what would essentially be a billboard in front of your hoop building. We would recommend tearing down the hoop building and replace it with a new post frame building which would be structurally sound and a permanent structure.

 

DEAR POLE BARN GURU: I have a 56×40 pole barn that I am working on lining and insulating. My question has to do with ventilation. There is no soffit. Does Hansen make an eave vent similar to their vinyl gable vents with the snap rings? They would need to be approx. 6 inches wide by 1 or 2 feet long. I would like to place something like that in between each truss (8ft centers) on the sidewall under the roof overhang. Or should I just do gable vents? We are installing a vented ridge cap. Thank You. DARRIN in ARKANSAW

DEAR DARRIN: Unless your trusses have raised heels deeper than whatever insulation thickness you intend to use plus vent height, adding vents at sidewall tops will not solve your ventilation issue. Ridge vents do not function well with gable vents as intakes, so I will make one of two suggestions –

If insulating at ceiling level, use gable vents only following this:

2015 IBC (International Building Code) ventilation requirements may be accessed here: https://codes.iccsafe.org/public/document/IBC2015/chapter-12-interior-environment please see 1203.2.

In areas closest to sidewalls, use closed cell spray foam insulation until you reach an area where full depth blown in fiberglass insulation can be used (20″ will provide recommended R-60 for your area).

Or – use no vents and closed cell spray foam underside of roofing and triangles of gable ends.

 

DEAR POLE BARN GURU: How is the plumbing in pole barn construction affected in an earthquake? I have heard that since the pole barn construction is not anchored down, it shifts during an earthquake causing all kinds of damage to the plumbing? CARLOS in SPRINGDALE

DEAR CARLOS: Pole barn (post frame) buildings are indeed anchored down – or least most should be. In our case engineers we utilize will specify a bottom collar of a minimum 18 inches diameter and 16 inches deep, at base of a 40 inch or deeper hole. Columns will be attached to a slab on grade, or restrained by an elevated wood floor, if over a crawl space. There should be no more damage to plumbing, due to an earthquake, for post frame construction, than there would be for any other form of construction.

 

 

 

Electrical Planning, Moisture Issues, and Ceiling Barriers

Today the Pole Barn Guru fields questions on electrical planning, moisture issues, and ceiling barriers.

DEAR POLE BARN GURU: Good Morning/Evening:     I currently have a 36′ wide x 48′ long with 12′ tall ceiling pole barn that I would like wire for lights and outlets.   I intend to run main power from the street pole to a meter base and into a internal breaker box.  I know you have/sell electrical planning layouts for the internal pole barn light/outlets and I would like to purchase a set for use as a general guide.  Can you tell me how I might purchase your pole barn electrical layouts, etc.??    Thanks for your help in advance.   Very Respectfully. BILL in AMHERST

DEAR BILL: Thank you very much for your inquiry. We do not involve ourselves in any sort of electrical. No electrical materials, no layouts, no plans. Try visiting the ProDesk of your local The Home Depot for assistance.

 

DEAR POLE BARN GURU: Hi I’m emailing because I’m having issues with moisture in my building it happens when it freezes and then thaws and it only drips from the pillars and I have moisture barrier inside can you please explain why that’s happening. ROBERT in CHEHALIS

DEAR ROBERT: We receive a handful emails with challenges such as yours every winter, from clients who recently had their buildings completed. It all goes back to where is moisture source?

If no concrete slab in your building, it is because ground outside of your building freezes before ground inside. When this occurs it is like pulling a cork from a bottle – all ground moisture from area surrounding building tries to escape through your building.

Have a fairly new slab on grade in your building? Moisture will be coming from it. As long as you have a well-sealed vapor barrier under your slab, you should only experience this issue for one winter. You can speed this process along by keeping large door(s) open on days when dew point stays lower than outside air temperatures (lower humidity, faster water will exit your slab).

If a well-sealed vapor barrier was not installed under your building’s slab, then slab surface should be sealed (once it dries out).

 

DEAR POLE BARN GURU: Hello. I plan to use foil backed foam sheets for my ceiling in my 28 x 34 Pole Building / garage. Reading your article, you would NOT put up a plastic barrier to control heat loss before hanging the Foam board? 4 / 12 pitch. Recommendation for hardware to secure sheets to trusses?
Thank you DAN in BUTLER

DEAR DAN: A plastic barrier would not make any difference in controlling heat loss, as it has no insulating value. Your foam board, if installed properly with joints sealed, will act as a vapor barrier. I’d glue it to truss bottoms to eliminate transfer of heat through nails or screws. Make sure to adequately ventilate dead attic space you are creating and a provision for preventing warm moist air from contacting roof steel underside exists.

 

 

Reader Put Up a Competitor’s Shed

We Put Up a Competitor’s Shed

Sadly not everyone does adequate research to realize how outstanding of a value added a Hansen Pole Buildings’ post frame building kit package truly will be. Long time readers of these blog articles (nearly 1600) and questions answered in Monday’s “Ask the Pole Barn Guru™” column (around 1000) have come to understand most problems solved by me come from other people’s buildings.

How serious am I about our value:
I am offering to shop for you. Yes you heard me right. You give me up to three names of competitors to Hansen Buildings, where you can purchase a complete wood or steel framed pole building kit package, and I will shop them to get quotes for you.
Now I say three, because frankly, some people just are not very prompt or cooperative when it comes to getting back with price quotes.

Why would I do this? Comparing “apples to apples”, I know our price will beat theirs, every single time. I am doing this for your peace of mind. I guarantee other prices will be higher. And I will provide you with documentation to prove it!

There is a catch…..before I go shopping, you have to place your order for your new Hansen Pole Building kit….. subject to me “proving my point” by going shopping. Your payment to us will not be processed for ten calendar days. Within seven days of order, you’ll have competitive quotes in hand, or my documentation of having hounded them every week day for a week trying to get pricing for you (seriously, if you have to hound someone for a price, what kind of service will you get after they have your money?).

After I email you proof, if you seriously want to purchase from one of these competitors, just let me know before ten days from your investment and we tear everything up and go away friends.

Ask The Pole Barn GuruReader DAVE in ROBERTS apologizes for buying from a competitor and writes:
“Sir. Your blog has been most helpful. We put up a shed not one of yours but a competitor. (sorry). Shed size is 36×48. First mistake was we did not put a barrier under the concrete. Our plan now is R 19 in walls. One inch of foam plus R 39 in ceiling. I wired in two ceiling fans to move air with natural gas heat. Does this sound like a good formula, oh wise one?

Mike the Pole Barn Guru says:
Start by sealing your building’s concrete slab. This will be a possible solution: https://www.hansenpolebuildings.com/2018/11/siloxa-tek-8505-concrete-sealant/.

I am just not a fan of natural gas heat as it adds a tremendous volume of water vapor into your building. You’re going to have to find a way to exhaust all this water, else your building will have humidity issues.

Although now too late for you, there would have been alternatives: https://www.hansenpolebuildings.com/2016/12/modern-post-frame-buildings-geothermal/.

Let’s discuss your ceiling. I am hopeful you have trusses designed to support a ceiling load of five psf (pounds per square foot) or greater. Also hoping you have ventilation covered with enclosed vented eaves and a vented ridge. Unless you specifically asked for it, your building’s roof trusses probably do not have raised heels to allow for full insulation thickness above walls and in area closest to sidewalls.

Provided your trusses will support weight of gypsum wallboard, install any necessary framing to reduce drywall spans to two feet or less. Place 5/8” Type X sheetrock across bottom of ceiling framing. If you do not have a vapor barrier under your roof steel, spray two inches of closed cell foam insulation across the entire underside. Once you have paid for this, you will regret not having made other condensation prevention decisions.

While spraying foam – have it added to area closest to eave sidewalls (spraying onto top of ceiling drywall). Make certain to leave an inch of airspace minimum above foam, so air can flow in from eave vents. Foamed area should continue towards center of building until it reaches at least a six inch thickness. Balance of ceiling should have no less than R-45 and ideally R-60 of fiberglass insulation blown in.

For walls, I am hoping you have placed a Weather Resistant Barrier (WRB – like Tyvek) between framing and siding. If not, you have a couple of choices. You can remove wall steel from a wall, install a WRB and reinstall steel (repeat for each subsequent wall), or spray two inches of closed cell foam to inside of siding. Unless your building has full thickness bookshelf girts, install framing across inside of walls to eventually support wall finish (I recommend sheetrock). Fill entire insulation cavity with BIBs https://www.hansenpolebuildings.com/2011/11/bibs/.

Glue two inch thick closed cell rigid insulation panels to inside of wall framing, sealing all joints. Glue sheetrock to inside of insulation. Now you have a truly well insulated post frame building.

A Steel Ceiling, Wall Finishes, and Condensation

Today Mike addresses questions about steel ceilings, options for wall finishes, and condensation in added space.

DEAR POLE BARN GURU: I have a 40ft wide x 60ft long x 12ft high pole barn. The trusses are 4ft on center. I want to put a steel ceiling up and wanted to know the best size piece to use when putting it up. 8, 10, or 12. MICHAEL in TABERNACLE

DEAR MICHAEL: Before consider this move confirm your trusses are designed to support added ceiling weight across bottom chords. Also, make certain to adequately ventilate dead attic space you will be creating (read about adequate ventilation here: https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/).

Having satisfied above, if you intend to merely attach steel panels to truss undersides and run panels lengthwise, I’d go with 28’ and 32’ long pieces to minimize splices. If framing has been placed between trusses to support steel running across building, go with full length panels and have no splices.

DEAR POLE BARN GURU: Hello.

We have a new pole building and are looking at options for finishing the interior walls. The building has been well insulated and will have a heater and AC unit. Besides drywall, what other options are available? LISA in MIDDLETOWN

Finished Pole Building InteriorDEAR LISA: Gypsum wallboard (sheetrock) will certain be most common as well as most popular option. If you go with 5/8″ thick Type X, it will also be fire rated. You can use any material for covering walls one would find in any type of building – however most of them are still installed over sheetrock. If for a shop building, 7/16″ OSB proves to be quite popular. Some people like steel liner panels, however I find them difficult to attach things like shelves and cabinets to and they get dented.

 

DEAR POLE BARN GURU: Greetings.  I have a 20-year old 40×25 post and beam barn, 2 story, shiplap siding, with metal roof and concrete floor.  Last summer I walled off a 11.5×25 area for a workshop (10ft ceiling) and noticed a lot of condensation this past spring (after pouring the concrete floor last fall). The workshop is used sporadically from spring through fall. I would appreciate your advice on how to address condensation issue and any recommendations for insulation.  Thanks for your time. RALPH

DEAR RALPH: Your increase in condensation most likely comes from moisture leaving concrete as floor cures. If you placed a good vapor barrier properly under slab, it should eliminate this as a source of moisture for condensation. If you did not, then you will want to seal slab with a high quality sealant. If condensation issues continue, it may be necessary to add a powered exhaust vent. Click here for further reading about insulation for different post frame uses: http://www.hansenpolebuildings.com/2018/06/pole-barn-insulation-part-ii/

 

 

 

 

 

Will My Post Frame Building Support a Ceiling?

Will My Post Frame Building Support a Ceiling?

One of my frequently received questions – wanting to add a ceiling into a post frame building and wondering if the building will support the added weight. Other frequent questions include condensation issues and ventilation, so this reader has hit upon a trifecta.


Reader BRYAN in SWANTON writes:

“I am having some condensation issues. And I was curious about insulating the building. Also wanted to ask if my building is able to have a ceiling installed. Thanks for the fast reply.”

 

 


By any chance have you recently poured a concrete slab-on-grade inside of your building? If so, until concrete fully cures, it will expel a great deal of moisture inside of your building. Solution – open your doors to allow moisture to escape and keep them open until condensation issues no longer exist. Read more here: https://www.hansenpolebuildings.com/2018/01/condensation-roof-steel/.

 

If you poured a slab without a well-sealed vapor barrier underneath, it will contribute to excessive moisture challenges. If no vapor barrier, top of slab should be sealed: https://www.hansenpolebuildings.com/2018/11/siloxa-tek-8505-concrete-sealant/

 

Your new post frame building and its trusses were not ordered to be able to support the added weight of a ceiling. It may be possible to upgrade your trusses with an engineered repair to be able to carry a bottom chord dead load of five psf (pounds per square foot) or more. Plan upon an investment of $295 (plus sales tax if applicable), even if a truss repair cannot be designed. Contact Justine at justine@hansenpolebuildings.com if you are interested in going this route.

If you are able to get a repair to install a ceiling, this newly enclosed attic area will need to be adequately ventilated. This may be a possible solution: https://www.hansenpolebuildings.com/2018/07/my-pole-barn-needs-ventilation/

In order to insulate, best solution (although costly) may be to use closed cell spray foam insulation. If you purchase an insulation kit for your overhead door, you will need to change out door springs in order to handle the added weight.

 

 

Whiskey Tango Foxtrot! Is It Ventilation?

Whiskey Tango Foxtrot! Is it Ventilation?

I really enjoy good food. In order to continue doing so and avoid weighing significantly more than I should, I do a treadmill run nearly every morning. To keep from expiring from utter boredom of exercise, I have wall mounted my flat screen LED television within easy viewing distance. With subscriptions to Amazon Prime and Netflix, I have yet to run out of movies and series to view. Most movie selections are either fairly old, or were box office challenged. One of these movies was 2016’s Tina Fay starring in Whiskey Tango Foxtrot, with a budget of $35 million and a box office take of $18.3 million.

Well, this article isn’t about how Tina Fey carried this movie. To be precise, it’s a movie title conveying my expression upon doing some recent reading.

Back in 2016 I had penned an article (https://www.hansenpolebuildings.com/2015/06/overhang/) mentioning a specific pole building company by name. A representative of this company recently contacted Hansen Pole Buildings’ owner Eric to let him know they did not appreciate being named. I was even kind enough to have included a live link to their website in my article, providing them with free press.

While editing, I happened to peruse their website. When a Whiskey Tango Foxtrot moment hit me…..

Under ‘Building Features’ I found this gem, “(Our standard roof to eave or gable design creates a fully ventilated structure making boxed overhangs an option, not a necessity)”.

I had to read it several times to fully get my head around what I thought I had read.

In order for this statement to be true, roof steel high ribs would need to remain unobstructed – allowing a free flow of intake air. This could possibly pose a challenge if one desires to keep small flying critters from entering a dead attic space.

In my humble opinion, this attempted ventilation intake ranges from laughable to totally ridiculous. However, I have found, nearly anything can be spun to sound like a benefit. What should be happening between roof steel and eave strut – placement of an Inside Closure (https://www.hansenpolebuildings.com/2015/12/the-lowly-inside-closure/), to seal these openings.

IBC (International Building Code) 2015 Edition tends to agree with me.

“1203.2.1 Openings into attic.

Exterior openings into the attic space of any building intended for human occupancy shall be protected to prevent the entry of birds, squirrels, rodents, snakes and other similar creatures. Openings for ventilation having a least dimension of not less than 1/16 inch and not more than ¼ inch shall be permitted. Openings for ventilation having a least dimension larger than ¼ inch shall be provided with corrosion-resistant wire cloth screening, hardware cloth, perforated vinyl or similar material width openings having a least dimension of not less than 1/16 inch and not more than ¼ inch.”

Thinking about a post frame building other than from Hansen Pole Buildings? Before possibly throwing away your hard earned cash, give us a call – if we feel someone else’s building has a better value than ours, we will be first ones to tell you to invest in it.

 

Mold in a Post Frame Building Attic

Hansen Pole Buildings’ client BRENT in WASHOUGAL writes: “We have your 40×80 pole barn built sept. 2014, and it’s having problems with mold forming over the purlins. I’m wanting to know my options to prevent a future problem.

Thanks.”

Mike the Pole Barn Guru responds:

First – get rid of the mold. Mix in the ratio of one cup bleach per gallon of water and use a hand pump sprayer to saturate all moldy surfaces. You can also use a scrub brush to remove the existing mold.

The most common causes of attic mold are leaking roofs, inadequate ventilation and too much humidity in the building itself. If your concrete floor has a vapor barrier underneath it and/or is well sealed, you are probably not drawing in excess moisture from underneath the building – so we will look at the first two.

Mold showing along the tops of the roof purlins and not on the trusses, as well as the streaks down the sides of the purlins leads us to believe you may have screws which were inadequately placed. Screws which are not properly seated so as to compress the rubber washer, will leak. Screws which are driven in at an angle will also cause leaks. The roof should be investigated screw-by-screw to make sure all screws are properly driven. Water leaking around a screw shaft will eventually cause decay of the wood around the shank, so if screws cannot be tightened they should be replaced by a larger diameter and longer screw – in your case a #14 diameter by two inch long part.

Ventilation – in an ideal word your building would have had enclosed vented eave overhangs of 18 inches or greater on both sidewalls for an air intake, as well as a vented ridge to provide an exhaust point. This ventilation system provides for even airflow from eave to ridge throughout the entire attic area. Gable vents can be used to meet Code requirements for ventilation, however the reality is they are not very effective in providing ventilation other than near each end of the building’s attic. The Code requirement would be for 1/300th of the footprint area of the attic to be provided for as net free area of venting, as long as at least 50% of the venting is in the top half of the enclosed attic space. With a 40′ x 80′ building, you have 3200 square feet of footprint, which would require at least 10.67 square feet (or 1536 square inches) of net free ventilating area. To give an example a Mid America (www.midamericacomponents.com) Classic Rectangular vinyl vent 20 inch by 30 inch provides 297 square inches of net free ventilation area, so it would take three of these in each endwall just to meet the requirements of the Code!

There also is a difference between meeting Code requirements and what actually works in a real life situation.

Since you cannot increase the amount of venting in your soffits (as you have none), you’ll need help from power vent fans to exchange the moist air in your attic for dryer, outside air. Attic ventilation fans would help move the moist air out of the attic without giving it time to find a home on the purlins and trusses.

Attic vent fans can be hard-wired and equipped with a thermostat and/or humidity sensor so they automatically cut on at a preset moisture level or temperature. You could also install solar-powered attic vent fans, though it has been found most solar models aren’t powerful enough to be very effective.

To determine what size power vent fan(s) you need for your attic, you first need to know the size of your attic in square feet.

Attic Size

To determine the size of your attic, multiply the width by the length of the attic floor in feet. In your case 40′ wide x 80′ long = 3200 square feet of attic space.

Vent Fan Size

Next, multiply the square feet of attic space by 0.7 to get the minimum number of cubic feet of air per minute the fan should be rated to move. 3200 sft x 0.7 = 2240 CFM minimum fan rating.

Add an additional 20% (CFM x 1.20) if you have a steep roof, and 15% (CFM x 1.15) for a dark roof. Attic vent fans are commonly rated from 800 to 1,600 CFM, making one fan suitable for attics of up to around 1160 square feet, even with a steep, dark colored roof.

Vent Fan Location

Install gable mounted fans on the gable vent at end of the building facing away from the prevailing winds.

Intake Air Vents

It’s also important to have plenty of soffit or gable vents for the fan to draw air into the attic. To find out if you have enough vent space, divide the cubic feet of air per minute the fan(s) is rated for by 300 to come up with the minimum number of square feet of intake vent space needed for that size fan. 2240 CFM ÷ 300 = 7.47 sq. ft. intake vent area

If you prefer the answer in square inches rather than square feet, multiply the answer by 144 and round to the nearest inch (7.47 x 144 = 1075.2 sq. in. vent area).



 

 

How Not to do a Post Frame Sheer Wall

How Not to Do a Post Frame Shear Wall

Reader DAVID in MIDDLETON writes:

“Hi we are currently building a 40/72 pole barn. We are wrapping the bottom 4 feet in OSB for sheer strength along with sheeting the roof with osb. We want to insulate the walls and put a drop ceiling in the pole barn to fully insulate it later this year. What do we need to do now for ventilation while we are building it to make sure we don’t have condensation issues later.”

Whilst friend David is writing about one issue, he is throwing out a bone as to why self-engineered post frame buildings are not always the best route to go. David is well intentioned, however his design solution would result in added expense without added benefits.

Always (may I repeat Always) construct only post frame (pole) buildings which are designed by a RDP (Registered Design Professional – engineer or architect) specifically for your building upon your site. You will always get piece of mind and usually the RDP will save you more money than what you invested for their design work.  

Here is my response to David:

Before we get to discussing your question, a few words about your design.

Wrapping the bottom four feet in OSB is going to do little or nothing to improve wind sheer resistance. In order to be effective as a sheer wall, the OSB needs to run from the splash board up to either the eave girt on the sidewall or the bottom chord of the truss on the endwall. All panel edges need to be blocked with 2x material. The shear panels should be no less than a 1:4 ratio (one foot of shear panel width per four feet of height) and ideally 1:2. On the roof, make sure to use at least 30# felt between the OSB and steel roofing and locate the roof screws so as they go into the underlying purlins, not merely into OSB.

Back to the question at hand…..

Your building should have vented soffits, of at least 18 inches in width to provide an adequate air intake. Trusses should be fabricated with raised heels – ideally two inches higher than the thickness of the attic insulation. Take care not to block the airflow from the soffit with the attic insulation. Vent the ridge.

Pour the slab on grade only over a well sealed vapor barrier, otherwise excess moisture will enter the building from the ground beneath the building. Also, the slab will need to be sealed – not as good as the vapor barrier route, but it is better than doing nothing.

Completely fill the wall cavity with insulation. Unfaced batt insulation can be used, however BIBs will be a fair superior design solution. Read more about BIBs here: https://www.hansenpolebuildings.com/2011/11/bibs/.

Either choice of wall insulation requires a clear visqueen vapor barrier on the inside. Make certain to seal any seams, rips or tears. There should not be a vapor barrier between the ceiling framing and ceiling materials.

 

 

Considering a Pole Barn, Roof Loads, and Proper Ventilation

DEAR POLE BARN GURU: Good morning.

I am considering building a pole barn on our land in northwest Georgia and wanted to know the following:

1) On your website, you list links for residential, agricultural, and commercial buildings.  What is the difference between a those three types of buildings?  Are they different because of design or do they each involve different construction materials?  Do the commercial buildings use a lower gauge (thicker) sheet of metal for siding than a residential building?

2) Do you have any product comparison documentation between your kits and the other pole barn kits on the market (DIY, Menards, etc.)?  Interested specifically in design, material, and construction comparisons.

3) Would your pole barn kits be able to accommodate a chimney/stove pipe if I wanted to use a wood burning stove for heat?

Thanks! CHRIS in RISING FAWN

About Hansen BuildingsDEAR CHRIS: The differences for residential, agricultural and commercial buildings shown on our website are for the convenience of those who are looking for a particular end use, it keeps from having to browse through a plethora of photos of buildings which may not be what one is looking for. The construction materials and methods used are going to be individually tailored to the ultimate end needs of each client, as well as the climactic conditions of a particular site.

Our goal is to custom design for you a building which best meets your wants, needs and budget. We are so confident in our ability to provide the best possible value for your post frame building investment, once this is done, we would happily shop this building for you with any other provider or providers you so desire. How easy is this?

(BTW – Menards might be a bit geographically challenging as their nearest location to you is in Owensboro, KY)

Actually any post frame building (not just a Hansen Pole Building) can accommodate a chimney/stove pipe with the use of a Dektite® (read more here: https://www.hansenpolebuildings.com/2012/09/dektite/).

 

DEAR POLE BARN GURU: I have a 30 year old pole barn that is 30’ x 40’ x 9’ tall. It has a metal roof, trusses are 4’ on center. Can I tear off the metal on the roof and put down OSB and shingles? JIM in LAWTON

DEAR JIM: Chances are excellent your existing roof system is not designed to support the weight of OSB and shingles, as most pole barn (post frame) trusses are designed for a dead load of only 3 to 5 psf (pounds per square foot) which includes the weight of the trusses themselves plus the roof purlins. Steel roofing weighs in at under one pound per square foot. 7/16″ OSB comes in at roughly 1.5 psf, 15# felt and shingles 2.5 psf making the weight combination more than four times greater than the steel.

The big question is – why? Even “lifetime” shingles will usually last only about 15 years and you know the steel roofing you have had made it twice as long. Steel is far more impervious to weather (especially hail) and readily sheds snow, unlike shingles. For my money, if I had to re-roof I would invest in steel roofing with a high quality paint system like Kynar. Read more about Kynar here: https://www.hansenpolebuildings.com/2014/05/kynar/.

 

DEAR POLE BARN GURU: I have a pole building with all metal sheeting. The interior walls are framed and insulated R13 batt. The ceiling is insulated with 1/2 foam a 3/4″ air gap then R19 on top. The underside of the roof is not insulated. I have eave ridge vent. Building is heated in winter. Can I exhaust fumes (paint,lawnmower,etc.) into the attic space and let it vent out the ridge or will I be causing a condensation problem? I will use a standard box fan to blow exhaust into the attic space. I’m also hoping to do this to help melt snow off the roof.
Thanks. RICH in LEHIGHTON

crash-test-dummy-symbolDEAR RICH: I’ve seriously struggled with your question for several weeks now. It lead me to spend hours researching the International Mechanical Code (I am proficient in the IRC and IBC, but not the IMC), looking for backup as to your scenario. In the end it all comes down to this – WHY would you want to dump toxic fumes and their waste into your attic? At some point this has got to be just plain unhealthy.

Whether you do or do not blow exhausts into your attic, your building has the strong potential for a condensation problem because there is no thermal break below the roof steel. You should look at having closed cell spray foam installed on the underside of the roof steel.

As to the heat from the exhaust helping to melt snow off the roof – do not count on it, by the time it gets into your attic, the heat generated will be minimal at best.

Turf Sweating, A Post Frame Addition, and A Grow House

DEAR POLE BARN GURU: Hello, I am from Webster SD and I built a pole barn and insulated it.  I then put turf above gravel floor and use it for a indoor baseball practice facility.  It can be heated as we have heaters in there.  We have a huge problem and was wondering if you could help us solve it.  I went in there today and the humidity was 85%.  Under the turf is wet.  What is causing this and how do we solve it?  We have bats in there that are showing early signs of rust and it has been closed up for about a month.  Thanks, CHAD in WEBSTER

DEAR CHAD: The water is coming from the ground, and even makes its way up through concrete. You will need to remove the turf and then install a high quality sealed vapor barrier which is resistant to punctures or tears beneath it. In the research I have done, it appears the folks at Americover (www.americover.com) can probably make the best recommendations as to the product which will best fit your needs and budget.

Depending upon how you have insulated the building, it may also be necessary to add ventilation in order to remove excess humidity from the air.

DEAR POLE BARN GURU: Can a pole barn be mounted to a house that has a cinder block foundation? RAY in BROCKPORT

DEAR RAY: If the question is can a pole barn (post frame building) be mounted to a block foundation, as long as the foundation is adequate to carry the imposed loads, certainly. Brackets are made to either pour into a foundation, or be retrofitted to one.

If you want to attach a post frame building to a house with a cinder block foundation, the post frame building would not structurally rely upon the block. Instead, it would typically be a free standing structure abutted to the existing building and foundation.

 

 

DEAR POLE BARN GURU: Is a 28×24 pole barn with 8 foot ceiling height large enough to start a grow room? ELIZABETH in DUNDEE

DEAR ELIZABETH: It will depend upon how many plants you intend to grow. A mature plant requires four square feet of area and you need to have space to walk alongside. The eight foot high ceiling might be a bit tight as well, as some plants have the capability to grow to be as tall as a house. My best recommendation is to err on the side of caution and construct the largest footprint building which you can economically justify and which will fit within the available space.

 

 

Premature Roller Wear, Proper Insulation, & Venting!

DEAR POLE BARN GURU: My Plyco rollers are wearing prematurely since I added liner to my doors. Can I put a 3rd roller in the center of each leaf to spread out the additional load? BRAD in EL DORADO

DEAR BRAD: If these are round Plyco trolleys, your door must be very heavy. I say this because I have never heard of one failing and we have thousands of sliding door in use by our clients. With this said, placing another one in the middle will probably result in the door sliding unevenly due to the slightly larger (due to no wear) new trolley in the center. Plyco does have what is referred to as a “double truck” trolley. These will replace your existing trolleys and each has two sets of wheel pairs. If you have a heavy sliding door, these are probably going to be your solution.

 

 

DEAR POLE BARN GURU: Can I use post frame insulation on the ceiling of my home. It is an add-on used as a day room. OVERTON in NATCHEZ

DEAR OVERTON: Could or should? Not the same question. You should be blowing at least R-45 of cellulose or fiberglass into a properly vented insulation cavity. If you do not have adequate thickness at the top of the walls, Add high R insulation boards as baffles so at least 2” of clear airflow comes through from the eaves. Then have closed cell spray foam insulation added until the R-45 blown in can reach full depth. Generally this should be about four feet from the walls in standard residential stick frame construction.

 

 

DEAR POLE BARN GURU: My question involves venting of the attic space. If the eaves are closed off, will the ridges in the roof metal not work as air channels to allow outside air to enter the attic space in the same manner as soffit vents? The plan would be to install a ceiling, blow in insulation and install ridge vents in the roof. MIKE in INDIANAPOLIS

DEAR MIKE: The ridges of the steel will not provide adequate airflow. Plus, they should be sealed off with inside closure strips to prevent flying critters from entering your building. If you do not vent the ridge, you can meet the ventilation requirements with gable vents. Read more on attic insulation for post frame buildings here: https://www.hansenpolebuildings.com/2014/02/pole-building-ventilation/.

Post Frame Antiperspirant- Ventilation Frustration

This is a sad story I hear all too often from pole (post frame) building owners who have buildings which were not properly designed for future uses, especially when it comes to insulation and ventilation.

Reader JASON in TENINO writes:

Hi Pole Barn Guru,

I recently purchased a new house and it came with a 40×60 shop. This past year I’ve experienced terrible slab sweating every time there is a change in humidity. Now that it’s summer I would like to prevent the sweating from occurring again. What are my best options on a limited budget? I’ve looked into using a penetrating concrete sealer, but I don’t think that addresses the underlying condensation problem.

As far as I can tell the shop has no ventilation of any kind (ridge/gable/soffit). And I’m noticing black mold starting to develop in the insulation below the roof. And I’m not sure if any sort of vapor barrier was placed before the slab was poured.

In the future I would like to insulate and heat the shop, but for now, I’d be happy if I can stop my condensation problems.

Thank you for your help!!!

DEAR JASON:

Yep – you have a problem on your hands. I can pretty much guarantee there is no vapor barrier under your concrete floor, which is a shame someone cheaped out. Vapor barriers are so inexpensive.

Taking care of first things first, let’s get the floor sealed. Here is the information you will need: https://www.hansenpolebuildings.com/2012/07/concrete-sealer/.

Secondly – get rid of the mold. Mix in the ratio of one cup bleach per gallon of water and use a hand pump sprayer to saturate all moldy surfaces. You can also use a scrub brush to remove the existing mold.

Third – I am going to leap ahead to your future plans, as they will impact your solutions now. I am not a gambling man, but I would put money on your shop’s trusses not having been designed to support the weight of a ceiling. This means if you want to eventually insulate and heat the building, you will have to insulate above the bottom chord of the trusses and up the roof line. On the walls, you can frame in either with a stud wall or with bookshelf girts to create a method to support insulation, with either batts or BIBs (Blow in Blanket) insulation being the most cost efficient and effective for your investment dollars.

Insulating the roof, not so easy, as the only really practical solution will be to use closed cell spray foam between the roof purlins. You will want to consult with an installer to get their opinion as to whether the metal building insulation under the roof steel will have to be removed prior to spraying.

If you are going to spray foam, then you do not want to use a ridge vent, as the foam would cover it.

Here is my best advice (provided you have the space on your property) – use your existing building only for cold storage. Since you do not have vented sidewall overhangs to create an air intake, the only solution for ventilation is to use large vents in each endwall. At a bare minimum, you should have at least 576 square inches on net free flowing vent in each end – located in the top half of the gables. You may need to add power vents, in order to adequately move the moisture out of the building.

When your budget allows for some climate controlled space, construct a new building which is properly designed to be able to be energy efficient.

Here is a short list of features which you should include:

Underslab vapor barrier
Pex tubing in slab for in floor heat
Perimeter slab insulation (rigid foam)
Bookshelf wall girts to create an insulation cavity
Housewrap between wall girts and siding
Vented sidewall overhangs
Ceiling loaded trusses with ceiling joists
Raised heel trusses to allow full insulation depth from wall to wall
Blow in R-45 to 60 of ceiling insulation
Reflective radiant barrier between purlins and roof steel

Good luck and let me know how things turn out!

Mike the Pole Barn Guru

Turn a Horse Barn into a Home?

Re-purposing buildings is a popular American past time, as evidenced by the proliferation of big box lumber stores across the country. Here is a story about a new owner of an existing Hansen Pole Buildings’ horse barn, who is contemplating it becoming a home.

Tim writes:

“Hello, I just purchased a property that has a Hansen Pole barn that is new on it and I am wanting to convert to home any ideas and /or plans , I have attached a photo of barn  center section is 48×28 x14 and the 2 side sections are 48x12x10”.

Drum roll please:

You emailed me because you know and trust I am the expert and will not lead you astray. Or, this was the email address you happened to find, either one of which is totally fine.

In order to give you definitive answers I would need to know who the original purchaser of the building was, so we can pull up the plans and specifications for it, if they are available.

In the meantime, I will hope to give you my best guess answers. The existing building is most probably designed under Risk Category I of the International Building Code (being as it is used as a horse barn) which is for buildings of low risk to injure someone in the event of a catastrophic event. These would be non-residential structures. A residence is a Risk Category II structure – which has more stringent requirements for wind, snow and seismic events.

The real issues are most likely to come in designing to gypsum wallboard (sheetrock aka drywall) the walls and ceiling.

On the walls, the deflection criteria for walls which support drywall is much greater than a wall with only steel on the exterior. This can affect the size(s) of the columns and they may have to be added onto in order to provide adequate stiffness. It is likely you will use bookshelf girts on the walls to create an insulation cavity. If so, and they are properly sized, they should be stiff enough to support drywall.

The trusses, rafters and roof purlins are not designed to support the weight of a ceiling. This will require an engineered truss repair, as well as probably upgrades to the rafters on each side (addition of more members). If you are planning on attaching sheetrock to the underside of the roof purlins, more purlins will need to be added to reduce deflection – and the only real way to insulate between the purlins on the sheds is to use closed cell spray foam, which is not an inexpensive proposition.

Ventilation is going to pose an issue (which is why the closed cell insulation is the solve for the sheds). In the main portion of the building, if a dead attic space is created, it must be ventilated. I cannot determine from your photo if the building has enclosed overhangs or not. If they are enclosed and the ridge is vented, you are in luck. If not, then gable vents are the alternative and would need to be added.

My best recommendation – leave the barn and design a post frame home which truly fits your needs and lifestyle, rather than trying to fit what you want inside a preexisting box which requires a boatload of work to upgrade.

Shipped International, Post Protection, and EmSeal!

DEAR POLE BARN GURU: Can the kit be shipped international, like Philippines? ERIC in SUSANVILLE

DEAR ERIC: Post frame building kit packages can be shipped anywhere on the planet. In most cases, the components are delivered to the docks – in your case most likely the Port of Tacoma or Seattle, where it is reloaded into a container. As containers have a maximum exterior length of 40 feet, it will limit the length of any prefabricated wood roof trusses, unless they are designed to be built in halves and field connected.

Many countries will require the lumber to be treated with a fungicide in order to prevent possible contamination of their own forest resources.

 

The furthest I have personally shipped to has been Saipan.

 

DEAR POLE BARN GURU: I really like the idea of post frame construction for residential, not because it is cheaper but because I believe it is stronger. Maybe I should qualify that by saying it is stronger laterally (horizontally) but probably not vertically. What I envision as post frame is having posts made of pressure treated lumber like 6×6, 8×8 etc set deep in the ground in concrete, and these posts would extend to the top of the wall or where the roof begins.

My question is do you know of methods of treating the wood so that it does not rot so quickly? I was thinking that if one were to coat the wood in epoxy resin that would help greatly, but I don’t know. Or could you not encase it in some kind of liquid plastic that once dried you would stick the post in the ground. Thanks. JACK in COBB

DEAR JACK: Post frame buildings are actually incredibly strong in the vertical (compressive) direction as properly braced timbers can withstand a very large downward force. Post frame buildings will be more economical than any other permanent building system, as well as affording greater flexibility for architectural design.

Properly pressure preservative treated lumber will outlive you, me and probably our grandchildren. If I did not believe so, I would not have invested the money in owning three of them myself, including the 8000 square foot finished building we live in. If you are yet concerned about longevity, there are currently available commercial products which will isolate the columns from the surrounding encasement (https://www.hansenpolebuildings.com/2012/04/plasti-sleeves/).

 

DEAR POLE BARN GURU: Hi Mike, I recently found this blog and man is it helpful. I have been remodeling a 1977 24×40 pole building. Never had one before and I’m learning as I go… hoping I can build a new one later in my life I’m only 29. I completely replaced the roof/trusses etc. and installed bubble insulation under steel for condensation. No soffit only Ridge vent. I want to seal up my gables up to peak. How should I do this? Solid closure strips? Vented closure strips? Or Emseal AST? Thanks for your help and hopefully I can order a new building from you in the future. ZACH in BLACK CREEK

DEAR ZACH: Thank you very much for your kind words! I will guess your building has no endwall overhangs, if this is the case the best way to seal up those endwalls is to use Emseal AST (https://www.hansenpolebuildings.com/2016/03/emseal-self-expanding-sealant-tape-closures/) between the rake trims and the endwall steel.

 

If you have endwall overhangs, you should be able to use spray foam in a can (such as Great Stuff or Tite Foam) from inside of the building to spray up the high ribs of the endwall steel.

 

Blog Entries Lead to Post Depth Question!

DEAR POLE BARN GURU: Good morning.

I have been reading the various blog entries for several days, regarding pole barn construction.  I have been in contact with your design professional, but I a question that I thought might be a question that could possibly benefit others with a similar situation.

I am in the process of planning a 40X60 building for a shop for the business I have.  My planned (and only available) location has about 5′ of fall on the lot which would be on the 60′ side wall of the building.  I have built up a 50 X 70 pad.  This has been built up and compacted with red “clay” a term we use around here, referring to the material we call “fill” around here, generally used for the purpose of building up a building pad.  My original thoughts were to place a 6″ thick monolithic concrete pad with a footer, (I intend to run forklifts on it.) and erect a steel building kit.

Since the dirt pad was completed, I have since stumbled onto your site, and am looking at a pole building.  So, my question relates to setting poles.  How do you handle setting poles when half of the building will be over the top of built up soil base?  I know it can be done, and I am not concerned overly much with adequacy of the soil compaction, which at this point, it has been sitting for about 7 or 8 months since it was compacted, but it has not been tested for compaction.

But having never done this before, since I am not 100% sure, and have yet to dig holes, (but I do want to start later this spring) I wanted to know your thoughts before I proceed.

Thank you. WESSLEY in TRINITY

DEAR WESSLEY: And a fine good morning to you!

I believe you are going to find a post frame (pole) building to be a much more viable option for your new structure than all steel and this is why….

Although your fill has sat for 7-8 months, there is yet a chance of additional settling. Clay is also a very unstable soil to place footings upon – so if your consideration was to support a monolithic pad with a footing around the perimeter, unless the footing was at the depth of the undisturbed underlying soil there is a high degree of probability the building would settle or shift – leaving you an unhappy new building owner.

With your pole building – the columns which will be placed in the fill area should be ordered long enough so the base of the column (actually the concrete below the base of the column) will rest upon virgin soil. This will require some holes to be as deep as five feet, however most skid loader mounted augers will get this kind of depth. The columns placed in this manner should minimize the probability of issues from settling and give you a resulting structure which can be happily used for several generations.

DEAR POLE BARN GURU: I can build a 28×36 pole building with 12′ eaves on my lot. I would like double trusses spaced 12′ so I can have 3 bays. What would be the difference in truss design for one designed for roof load only compared to one that can also support a ceiling. Thank you. JIM in SALEM

DEAR JIM: At the bare basics – the trusses will have one or more of the following: higher grades of lumber used for top and or bottom chords; large lumber for top and or bottom chords; more internal truss webs; larger pressed steel connector plates.

Now some recommendations – when you have a ceiling, ventilation is required. The best way to do it is to have enclosed vented overhangs and a vented ridge. This gives both an air intake as well as an exhaust and gives smooth airflow throughout the entire enclosed attic space. If you are planning upon insulating the ceiling, raised heel trusses are the way to go (read more on the hows and whys of raised heel trusses here: https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/).

You get one opportunity to do your new building right or wrong, I’d sure like to see it done right!

DEAR POLE BARN GURU: I bought a house with an existing 38×26 pole barn. The barn has metal roof placed over 3/4″ rigid foam (ISO) screwed to the purlins (2X4 on edge). I can’t tell what the facing material is on the ISO, but its white and doesn’t seem like paper. There is noticeable water staining on the rigid foam which I believe is due to condensation. There is a vent ridge on the barn. The metal roof is a PBR profile. For the winter I would like to insulate the cathedral ceiling better (I don’t want to drop a ceiling as I have storage shelving that prevents this). What is the best option (besides spray foam). I was considering kraft faced batts stapled to the 24″ OC purlins. I could do an R13 since the purlins are 2X4s, but also considered an R19 and let the batts bulge out a bit as I’m not going to sheath it. I would have the ridge foam to butt up against which should allow ventilation on the opposite side still (adjacent to metal roof). What do you recommend? I have wood stove for heating in the winter time and use it to take the chill off when I work out there (ie not on all the time). PATRICK in INDIANAPOLIS

DEAR PATRICK: I am going to give you the answer you probably don’t want to hear…..the water staining is most probably due to roof leaks, rather than condensation. This happens when screws are placed through foam board, which causes the screw shanks to deform, slots to form beneath the screw heads and when the deformations or slots get large enough – it leaks. The best solution for the problem is to remove the roof panels, take out the insulation boards and throw them away, then reinstall the roof panels using 1-1/2 inch long screws with a larger diameter than what was previously used.

Placing any sort of batt insulation under the foam as it currently exists is just going to get you wet insulation. Trying to use R-19 insulation batts in a 3-1/2 inch cavity will net you R-13 as the insulation is only as effective as its fully expanded thickness.

Once you have removed the foam boards the solution seriously is to spray foam it. Code requires airflow from eave to ridge over the batt insulation, which is going to involve more work and cost than the foam – it would take two layers of 2×4 laid flat on top of the existing purlins, one set running up the roof and another set going the same direction as the purlins, to screw into. This will mess up any trims on the perimeter of the roof, resulting in purchasing larger coverage trims.

The original building owner’s lack of planning for future uses of the building have now become your expensive nightmare.

6 Cool Ways to Heat Your Pole Building & Barn

When winter arrives, pole building owners will need more than a tiny space heater and a quilt to keep themselves warm. Sitting on the couch reading a book in thermal pants, a heavy jacket, and snow boots isn’t the most comfortable way to spend the cold months, so we’d like to suggest a few heating options for your pole barn.

Electric Floor
Electric floors radiate heat from underneath tiles, laminate, carpet, or engineered flooring. You can install bare wiring or opt for pre-wired mats that simplify the process. Mats are likely to cost more to install, but both systems use only a minimal amount of electricity.

Radiant Ceiling
Radiant ceiling tiles are long tiles on the ceiling, usually placed in increments, that generate and radiate heat. They are useful for targeting heat only in certain areas, such as in a living area above the couch or a bathroom next to the shower.

Radiant ceiling tiles, unlike electric floors, sit outside of the ceiling, not the inside. Some models are designed for painting and most will accept add-ons such as exhaust fans and lights.

Cove Heater

Cove heaters are silent-operating radiant panels mounted near the ceiling. They are a great option for heating safely with kids or keeping your heating equipment out of sight. Pole barn owners opt for these when baseboard heaters are difficult to install because of safety hazards or obstructive furniture.

Duct Fan
If you have a central heating system, you can add a simple fan to your ducts to increase the flow of warm air throughout your pole barn. Since there is so much empty space inside pole buildings, duct booster fans can help spread your heat evenly and might even help you save on your electric bill.

Mount your fan near the outlet end of a heating duct. The pressure switch will sense air pressure from the forced air coming out of the furnace and switch the fan on when it needs to be on. Higher quality fans emit less noise, but prices can range quite a bit.

Room-to-Room Ventilation
If your pole building has quite a few separate rooms to heat, you can circumvent your insulation and install a room-to-room ventilation system. These systems, installed as ducts in the wall, take warm air from room A through a low vent in the wall and push it up through a high vent in room B. Ventilators help draw the air through space between studs and distribute the warm air evenly into the adjoining room.

Ceiling Fan Heater

Ceiling fan heaters distribute air in the same way an ordinary fan does, but a heating element also provides the spinning blades with additional warm air to push throughout the room. Pole barn owners can turn the heating element off during the spring and summer to allow the ceiling fan to function like a normal fan.

Final Words: Stay Safe
You may have to deal with some unusual problems when battling winter weather. Remember the following:

  • Condensation Build-Up – Burning propane, methane, or kerosene can produce moisture in the air that, when it drops below the dew point, will cause water to condense inside your pole barn. Rapid changes in temperature can also pull moisture from the air and turn it to liquid. Use desiccators and dehumidifiers to control moisture in your pole building before it causes damage.
  • Ventilation – It’s tempting to trap all the warm air inside your pole building, but you have to let the air flow freely from inside to out and vice-versa. Proper ventilation keeps air fresh, oxygen-rich, and helps prevent heating-related disasters.

All heating creates some kind of fire hazard in your home. Be sure to operate all equipment according to instructions and prepare your pole barn heating system to resist fire by keeping it clean and having it inspected regularly.

Dear Guru: Can I Add to My Pole Barn in the Future?

DEAR POLE BARN GURU: I’m very interested in doing business with you, I just have a few questions. I originally asked for a quote of a pole barn of 200×50 I believe it was, my question is, can your buildings be added on to? Would we be able to start with something much smaller and then add on to the barn as we go? NOW IN NEW JERSEY

DEAR NOW: Yes, our buildings can be added on to. I would recommend the initial design be done with the idea of what the ultimate finished goal will be for size. Oftentimes, original structures are not structurally set up for the eventual expansion, which keeps the initial price low, but results in headaches and costs later, which could have been avoided with proper planning. A gabled roof will be the easiest roof style to work with when it comes to future expansion.

We have several customers who have done just as you suggest, adding on to one or both ends as they expand. Get the width you ultimately want, then adding length is much easier You can remove endwall siding, add on additional bays, and put the endwall siding back on. You may have to purchase more trims, but if steel siding, is easily reused for the addition.

And I always recommend – build as much building as you have space for and can afford economically, as whatever size you pick, it will never be large enough.

DEAR POLE BARN GURU: I’ve read ALL of your blogs!  Back to 2010. And love them. I write similar stuff in my business.

The question is do you have, or can you get, closures similar to ridge vent, but as a bottom closure to be used at the eave of a building without overhangs? BREEZY

DEAR BREEZY: Thank you for your dedicated readership and …good question! There is not such a beast, and even if there was, the net ventilation would be tiny – not enough to yield any positive results, as the only area which could have a vent would be just at the high ribs. The correct way to vent would really be with enclosed vented overhangs.

DEAR POLE BARN GURU:I have an existing pole building with badly deteriorating insulation and vapor barrier for the roof.

I plan to pull all of the old insulation and vapor barrier out to replace it.  I’d like to use the reflective radiant barrier / vapor barrier you recommend for new construction.  I’m considering pulling the metal roofing off to do it right so I don’t have to do it again later.

Do you recommend installing the reflective radiant barrier / vapor barrier between the metal roofing and purlins or between the purlins and roof trusses? DETERIORATING IN DELAWARE

DEAR DETERIORATING:
Place the reflective radiant barrier over the purlins and directly under the roof steel. You will need to use larger diameter, longer screws to reattach the roof steel.

DEAR POLE BARN GURU:Where can I buy Owens Corning Foamular Fanfold foam 1/4″ thick? A lot of my fellow RC plane hobbyists are having a hard time finding this stuff. Thanks in advance. FLYING IN FREMONT                          DEAR FLYING: Visit the Contractor Desk of any The Home Depot®. If it is not in stock, it can be ordered in within a matter of just a few days.

Dear Pole Barn Guru: I Have a Roof Mold Problem

ADDED BLOG DAY!  Due to a large volume of questions to the Pole
Barn Guru, we are adding another day for answering questions – so look for more Pole Barn wisdom from The guru on Saturdays – starting – today! 

Welcome to Ask the Pole Barn Guru – where you can ask questions about building topics, with answers posted on Mondays & Saturdays.  With many questions to answer, please be patient to watch for yours to come up on a future Monday or Saturday segment.  If you would like a quick answer, please be sure to answer with a “reply-able” email address.

Email all questions to: PoleBarnGuru@HansenPoleBuildings.com

DEAR POLE BARN GURU: Have a 45′ wide x 120′ long by 20′ tall pole building.  All walls are insulated and covered with plywood sheathing.  Bottom cord of all trusses also sheathed with 1/2″ plywood.  Metal roofing is installed over felt paper that is installed over 1/2″ plywood roof sheathing.  Building has continuous ridge vent and multiple 10″x20″ soffit vents.  None the less we still have mold growing on the bottom side of the roof plywood. Here in Oregon we get ALOT of rain, so frequent moisture issues.  Should I add gable end fans?  Roof fans?  Thoughts. RAINING IN EUGENE

DEAR RAINING: Provided the underside of the ceiling plywood does not also have mold growth, then the moisture is an issue from the enclosed attic space. By Code, the requirement for attic ventilation is for 1/150th of the area of the attic to be in vents, provided at least 50% is in the upper ½ of the attic and at least three feet above the eave vents. This net free area is to be equally divided between the eave and the ridge.

In your case, the minimum requirement would be 18 square feet at both the eave and the ridge. My guess is your ridge is inadequately ventilated, thus the mold issue.

You should begin by replacing your current ridge with a product such as the Klauer Roofline Ridgolator 4 (www.https://klauer.com/metalcomponents.html). With 220 net square inches of free air per ten foot section – your 120 foot long ridge would provide just over the bare minimum required for proper exhaust.

Powered exhaust fans in each gable would certainly help, provided they are located towards the peaks of the gables, and have sufficient capacity to be able to pull air from 65 feet away.

DEAR POLE BARN GURU: What is the depth i should place my poles in the ground in concrete 24×48 10 feet tall not in city. SOMEWHERE IN SNOHOMISH

DEAR SOMEWHERE: As the county you are building in requires Building Permits for all structures the size of yours, and they do a structural plan check prior to issuing permits – you will need to go by whatever is on the approved plans.

 

Not knowing your design wind speed and exposure, dead loads on the building, roof slope and soil bearing properties, I can only say typically I would expect holes 40 inches deep, with the bottom 18” backfilled with premix. In the event you are constructing a “pavilion” style (all walls open), then it would be best to entirely backfill the holes with

Windows – A View To The World

I really, really like windows. They give a view to the world. They can be used for ventilation. Those are good things.

To bring those of you who are just joining my daily blog up to date, I’ve spent this week building a garage – in Happy Valley, Tennessee.  My thanks for the opportunity to get back into the building mode courtesy of my oldest step-son’s father-in-law.  Back to my saga of building in 100 degree heat and nearly 100% humidity….

Steve wanted to make certain there was plenty of natural light into his building. So it has six windows. Considering one wall has two 12 foot wide by 9 foot tall doors, it gives an idea of what was going to happen on the other walls.

From a building standpoint – windows are a pain. I will repeat, windows are a pain. Every window on this building took the cutting of two panels of wall steel to fit around it. The cutting was not so much of an issue. For me it was a case of measure about 100 times, before cutting. Every one of the window cutouts worked just perfect, no botched jobs.

The real challenge, is sliding the panels into place around the windows.

For this building, windows with built in J channels were ordered, which I always recommend. There is little more time consuming, or more prone to a future leak, than having to cut steel J channels to fit around windows.

The less than fun part is having to slide the panels into the J channel at the top of the walls, and above and below the windows.  And then getting the overlap of one panel to slide over the underlap of the previously installed panel.

In the past, I’ve used a putty knife placed between the panels to allow the new panel to slide up over the prior panel. In this case, we found a new trick….we had to cut small strips off a few of the soffit panels, so we took the cutoff vinyl strips and used them as sliding skids. Worked out neat and was less trouble than the putty knife method.

Come back tomorrow and I’ll finish up on my construction week for Steve’s new garage.  After a week of sweating in the hot mid-July sun of Tennesee, I’ll be looking forward to getting back to my air conditioned office!