Tag Archives: moisture barrier

A BONUS PBG for Friday May, 17th– Roof Insulation, Column Sizing, and a Moisture Issue. 

A BONUS PBG for Friday May, 17th– Roof Insulation, Column Sizing, and a Moisture Issue.

DEAR POLE BARN GURU: Hi Mike. I built a post and beam shop and am trying to figure out how to insulate the roof on the second floor. The bents are true sawn 6×6 on ten foot centers (building is 40 feet long and loft is 16 feet wide). I used true 4×4 purlins on top of the 6×6 bents. I put 5/8 OSB over that, underlayment, then metal on top. I put a ridge vent system in. Now I’m looking at insulating the roof from the inside. I really have no air passage ways as the purlins run horizontally. My thought was to use 3 inch owens corning foam leaving a one inch gap to the OSB. I read your piece on closed cell spray foam for unvented roofs but mine is already vented. Can you give me any advice please? Thank you. MATT in ATHOL

DEAR MATT: While your idea is noble, it is impossible to place foam boards to completely eliminate warm, moist air from getting through cracks and seams. Eventually moisture will be trapped against underside of your OSB and there the fun (not really) begins. You really need to block your ridge vent and use closed cell spray foam. This article is in regards to another person in a similar circumstance: https://www.hansenpolebuildings.com/2023/10/properly-insulating-between-roof-purlins/

 

DEAR POLE BARN GURU: I am planning to build a 48 x 48 Monitor style pole barn that I intend to use for RV storage in the middle and living space above the center section. Will 6″ x 6″ posts be adequate spaced 12 ft apart or should I use 8″ x 8″? TIMOTHY in MARION

DEAR TIMOTHY: Your building columns will be sized by our engineers based upon building heights and loads carried. I would suspect our 3 ply 2×6 glulaminated columns produced from 2400msr lumber (roughly 50% stronger in bending than any other readily available columns) will be likely to adequately carry imposed loads.

 

DEAR POLE BARN GURU: When vinyl backed fiberglass insulation is installed on a metal roof, and is enclosed with rib closures and the roof extends 2″ over the purlin, should water still be able to reach the fiberglass? If so, should the fiberglass be replaced? Would this be something the contractor would be responsible for? Thank you. MARY in GREENEVILLE

DEAR MARY: Properly installed water should not reach fiberglass. If you see any fiberglass at juncture of wall and roof steel, then it was not properly installed. During installation, last roughly four inches of fiberglass should be removed from vinyl, then vinyl folded back over fiberglass. Folded edge should be even with outside of beveled eave strut (eave girt/purlin). If improperly installed contractor should at the least remove roofing to allow fiberglass to dry, then reinstall correctly.

 

An I-Beam Size, Plans for Permit, and Moisture Control

This Wednesday the Pole Barn Guru answers reader questions about an I-Beam size for a lean too, plans for a county permit- included with purchase of a Hansen Building, and advice for use of insulation and barriers for new build.

DEAR POLE BARN GURU: Hey Mike I’ve got a question for you, I recently just bought new double wide in Alabama my wife wanted a lean too off the back and sent me a photo, we just got the slab completed it’s 28foot by 76 foot I want to add a top but puzzled will a 28foot I beam support a metal roof without sagging? Or will I have to have a support middle ways through? Being we are going to drive in on one side I really didn’t want a post in the middle, also if a 28 or 30 ft I beam will support it how far apart should I place them to hold metal roof. Attaching pictures for what she wants/ what we have now. Thank you. DAVID in ALABAMA

DEAR DAVID: You will need an engineer to actually size an I beam for you, however you can clearspan the 28 feet. As for spacing of beams, it (and beam size) will depend upon what you intend to place between I beams to attach steel roofing. Again, same engineer can make this determination. One thing you do not want to do is to plan upon your double wide to support high end of your beams – over time this will result in all sorts of problems (such as cracks in interior finishes and windows not wanting to open). Instead, support beams with columns.

 

DEAR POLE BARN GURU: 28W x 30L pole barn, single 10’w x 9’t garage door, single entry door…need plans for county permit. Where can I get? DOUG in HAVRE DE GRACE

DEAR DOUG: Your new Hansen Pole Building investment includes site-specific full multi-page 24″ x 36″ engineer sealed structural blueprints detailing location and attachment of every piece (as well as suitable for obtaining Building Permits), our industry’s best, fully illustrated step-by-step installation manual, and unlimited technical support from people who have actually built post frame buildings. Please call 1.866.200.9657 tomorrow for details.

 

DEAR POLE BARN GURU: Building a new pole barn in a Texas barn style framing. I want to insulate the roof and walls. I plan to use 1-1/2″ EPS foil faced foam but am not completely positive where to put the vapor barrier to prevent condensation as if I do spray foam between the EPS and girths I’m concerned the spray foam will migrate into the rib blocking some airflow. Building will be 2×4 trusses 3:12 pitch 28′ wide on 2′ centers allowing the possibility to put a ceiling in at a much later date. Enclosed side lean to’s will be 2×6 rafters on the same spacing. I’ve gone down a rabbit hole researching a lot of forums and website data and believe the best way would be to install the EPS between the 2×4 girths and then a reflective radiant barrier. To clarify the girths will be 2×4’s laid flat and with the 1-1/2″ EPS there would be no air gap as bubble style wraps need to work properly. JOE in AUSTIN

DEAR JOE: If you want to do it right, spray two inches of closed cell directly to wall and roof steel and be done with it. If you are absolutely not going to use closed cell spray foam, then reflective radiant barrier should only be used between roof purlins and steel roofing, with well-sealed seams, as a condensation control. For walls – from outside to inside….steel siding, housewrap over bookshelf girts, Rockwool batts, interior vapor barrier, interior finish. For your ceiling, vents eaves and ridge, blow in insulation above ceiling.

 

 

To Vapor Barrier a Ceiling, or Not to Vapor Barrier a Ceiling.

To Vapor Barrier a Ceiling, or Not to Vapor Barrier a Ceiling.

Reader RAY in LAPINE writes:

“Hello, I live in Central Oregon, in climate zone #5. We are located in the High Desert at 4400 ft. The climate is dry with low humidity, occasional snow and cold in the winter. The summer temps are around 80 degrees, with large day to night temperature swings. Our heating hours per year are listed at approximately 7500+ per year. I am wanting to install 2×6 stringers, along with blow in insulation, but so many things are conflicting in my opinion, regarding my building when it comes to vapor barrier, no vapor barrier, heating hours per year, ventilation, etc., so I need your professional opinion. I have a 24×48 Pole barn, with double trusses, rated for 7 pound on the bottom cord. The truss bottoms are at 16ft off the concrete floor and are spaced 12 feet on center. The metal roof panels have dripstop that was factory installed. The walls have house wrap, behind bookshelf girts and was installed when the building was erected. The building has a continuous vented ridge, no soffit vents and is heated using a new, large, catalytic wood stove. I want to heat the building approximately 5-10 days a month, 8 to 10 hours a day for approximately 4 months of the year. So my question is, because of the drip stop panel coating and local heating hours, do I need any form of vapor barrier at the ceiling level or on the face of the purlins to avoid condensation issues??? I was originally going to install 10 mil, fire retardant, mesh reinforced poly on the bottom of the 2×6 stringers/trusses, wall to wall and blow insulation on top of the poly, then install 1/2 plywood painted white. Then I read not to use poly or a vapor barrier under 8000 heating hrs. After reading that, I thought I would use a air permeable product like ADO Insulweb, attached it to the bottom of the 2×6 stringers/trusses and blow insulation on top of that to R38, then install the plywood as stated before. Based on what I’ve read, it sounds like I need to install gable vents to the recommended ventilation ratio. Please provide me with your input and advice. Thank you.”

Spent many a winter day on Mount Bachelor’s slopes back when I lived in Oregon (even 4th of July one year), so am familiar with your turf (my step-brothers also live in your immediate area).

Based upon your information, I would install ceiling plywood and then blow in insulation directly on top of it. Paint your plywood after it is installed and this should be a sufficient vapor retarder. You will need to add gable vents, in lower half of your attic space. For a 24′ x 48′ building, you will need at least 139 square inches of NFVA (net free ventilating area) in each endwall, in order to provide sufficient air intake. This may require more than a single vent in each end.

Vapor Barriers, Post Longevity, and Spray Foam

This Wednesday the Pole Barn Guru answers reader questions about the need for a vapor barrier, the longevity of properly treated posts, and the better spray foam between open and closed cell.

DEAR POLE BARN GURU: Hello Sir, hoping you can help answer a question I cannot get a straight answer on. Currently building a 30x40x14 building and have the walls and roof house wrapped with Kelly Clark Block It. Steel is going on the building now. I just ordered steel for interior ceiling and trying to figure out if I should add a vapor barrier to bottom of truss first. Thoughts? MATT in ILLINOIS

DEAR MATT: Block it is wrong product for under roof steel. It allows moisture to pass through and be trapped between it and roof steel. As long as you do not blow in cellulose, you should not need a ceiling vapor barrier.

 

DEAR POLE BARN GURU: I bought a pole barn that has been retrofitted to a house. The posts are in ground. I’m worried about future resell and longevity of the post. Also, I’m in a cold climate and wonder if a proper footing would help with heating. Is there any good way to retrofit from in ground post to stem wall or something similar. I’m sure it’s all possible if money was not an issue. I’m looking for an economical solution. Thanks!! NICK in WEST LIBERTY

DEAR NICK: Properly pressure preservative treated columns (UC-4B) should outlast anyone alive on our planet today, especially in climates (such as yours) not prone to termite infestations. As for improving ability to heat – dig a trench around outside of building at least two feet wide and two feet deep. Invest in 2′ x 8′ (or 4′ x 8′ to be cut in half lengthwise), R-10 EPS insulation boards. Attach vertically to exterior side of pressure treated splash plank with top of insulation even with top of interior concrete slab. Run another 2′ horizontally out away from building at bottom of vertical. Any portion of vertical insulation above backfill will need to be protected from UV rays. This should keep your slab from getting so cold, as well as help to avoid frost heave. If you are in an area prone to burrowing rodents, you should further protect insulation https://www.hansenpolebuildings.com/2021/03/rascally-rodents/

 

DEAR POLE BARN GURU: I am trying to decide whether to go with open cell or closed cell spray foam on my bare metal pole barn walls. I will be enclosing the walls with some material, most likely plywood. What are your opinions regarding the pros/cons (is one or the other worse for corrosion, condensation, other pertinent factors, etc.) of the two foam approaches? Thanks so much! TERRI in CHESTER

DEAR TERRI: Open cell spray foam allows moisture to pass through and condense against steel cladding. I would not recommend it being used unless a two-inch thick layer of closed cell was first applied, then add open cell for extra R value (and to deaden sound).

Open Cell Spray Foam to Roof Steel – When Insulation is Done Wrong

Open Cell Spray Foam to Roof Steel – When Insulation is Done Wrong

Reader JOSH in FARMINGTON writes:

“I recently had a pole barn built and after doing a lot of research, went with 5″ of open cell under the roof and on the gables. I did not have any kind of vapor barrier, as I was worried the weight of the foam would cause it to sag and create air gaps where moisture could accumulate. I checked with the metal supplier to confirm it would not cause warranty issues and they said it would not. I am somewhat 2nd guessing the open cell, but I did it because I want to make sure I see any leaks that might occur from the exposed fasteners. I have not insulated the walls yet as I wanted to get all the electrical done. My plan was I would spray low expansion foam at the top and bottom of the metal sheets because right now there are no foam seals so you can actually see daylight even with the metal rat guards. To seal these up I want to use Great Stuff Pond & Stone foam. It’s black to match the trim in case it pushes out, it’s waterproof, it’s low expansion, and it’s UV rated. Then I was going to put 1.5″ foam board between the purlins, sliding it behind the posts. Following up with covering both with another sheet of 2″ foam board and use tape at the seams and some more foam at the posts. My thought is this would create a good vapor barrier, but I’m second guessing that now. For one reason, I don’t know how I’d seal things up above the header. They used a double 2×10 on each side of the post to act as the header. I do not plan to put a ceiling up and I will have a split system with a gas furnace installed soon to keep the space tempered between 60-80. I’ll heat it up or cool it down as needed when I’m using it. Do you see any issues with this setup? I’m a little worried about not having a vapor barrier on the roof. In Arkansas, we have all seasons, but it stays pretty muggy.”

My first concern is your open cell spray foam against roof steel. You have an application here I would never recommend. Open cell spray foam allows moisture to pass through, so you are going to end up with moisture condensing on underside of roof steel. I do not have a solution at hand for this – perhaps whoever installed your spray foam has some ideas.

As you propose to insulate your walls, you are creating a vapor barrier – meaning your walls will ‘dry to inside’ – adding even more moisture to potentially cause a problem in your open cell roof insulation. I would remove steel siding from a wall at a time, then install a well-sealed housewrap. Fill insulation cavity with rockwool batts (as it is not affected by moisture), with an interior vapor barrier. Walls will now dry to outside.

Chances are you are going to need to mechanically dehumidify your building in order to minimize condensation from moisture hitting roof steel.

Spray Foam Insulation on Interior Surfaces of Metal Panels

Spray Foam Insulation on Interior Surfaces of Metal Panels

Information excerpted from MBCI.com

When it comes to insulating a building envelope, there are various methods that can be used depending on the building’s purpose and the required level of insulation. However, combining metal roof and wall panels with spray polyurethane foam insulation (SPF) is widely considered one of the most effective ways to achieve secure, strong, and long-lasting insulation. Utilizing this method of insulation offers numerous benefits including the sealing of panel joints, creating a vapor barrier, providing thermal insulation, and producing air barriers.

One of the most notable advantages of utilizing SPF insulation is that it can be used to fill spaces in the panel assemblies and function as a key component of an air barrier system, effectively reducing air leakage. However, there are a few design parameters to be mindful of when considering the use of SPF insulation for metal roof or wall panels. The Spray Polyurethane Foam Alliance (SPFA) has conducted research on the installation of SPF on steel panels and has suggested the following best practices for applying SPF to the interior surface of metal panels:

Closed-cell foam is recommended due to its water-resistant capabilities.

SPF is a recognized insulation material to be used below and in contact with through-fastened metal roof assemblies.

The surface of the metal panel being sprayed should be free from moisture, lubricants, dirt, or other contamination.

The technique used to apply the SPF can affect the performance and appearance of the foamed panels.

Using a release fabric membrane between foam and a metal panel in a wall assembly is not recommended due to the potential of creating voids between the SPF and the wall panel.

There is potential for stress-induced deformation (or “oil canning”) on 29 gauge or thinner material. (This can be minimized by following the foam manufacturers’ recommended application technique.)

Always follow national and local code requirements for fire protection. Exposed SPF may require an additional thermal barrier or other means for fire protection.

Consider using an SPF contractor accredited by SPFA’s Professional Certification Program (1) (compliant with ISO 17024) to provide high-quality and safe installation of SPF insulation.

It is important that a certified foam spray technician applies SPF to the required insulation thickness to achieve the optimum insulation density, adhesion, and thickness. The recommended application method when applying the foam is to use the controlled thickness spray technique, commonly known as the “picture frame” technique. SPFA describes this technique as if someone were following through the motion of picture framing, in which the applicator surrounds the interior perimeter of the wall framing stud and allows the foam to rise along the stud. This technique can also help to prevent SPF from getting between girts and architectural metal wall panels which could cause metal deformation.

The thickness of the initial pass fillet during picture framing should be at least 0.5 inch and should not exceed the maximum pass thickness recommended by the foam manufacturer. The minimum thickness of the initial pass is specified to provide enough material to activate the blowing agent and initiate the cure. After picture framing the perimeter of the area, the applicator fills in the center of the cavity using the maximum thickness recommended by the foam manufacturer. Maximum pass thickness varies by foam formulation and is listed in the technical data for each SPF product. Excessive pass thickness can result in inferior quality due to the increase in foam temperature during curing. For most closed-cell SPF, the maximum pass thickness is 1.5 to 2 inches. It is important for applicators of closed-cell SPF to follow manufacturers’ installation instructions on pass thickness limits and proper cooling times between subsequent passes made if they wish to develop the desired total thickness of the insulation.

Installers are trained to check the substrate surface for moisture, dirt, oils, rust, or other conditions that can interfere with proper foam adhesion. It is also important to clean the surface of these contaminants prior to spraying the insulation. If there is uncertainty surrounding the amount of adhesion needed for a metal surface, this can be determined onsite using a pull-tester in accordance with ASTM (American Society for Testing and Materials) D 4541 (Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers).

When the time comes to change an outdated or damaged panel, many SPF contractors use a release material such as building wrap or fabric to allow for a seamless and pain-free swap out. However, it is important to keep in mind that the use of a release material poses the potential of creating air gaps between the back of the SPF foam and the metal panel. These gaps could allow condensation to accumulate between the SPF and the panel and framing members.

Closed-cell Spray Polyurethane Foam is a viable insulation material for the interior surfaces of steel and aluminum metal wall panels. This foam application can be highly nuanced, and there is a possibility of deformation, distortion, or oil canning if the application of the SPF is done poorly

What Bubble Insulation Brand do you Recommend, if Any?

What Bubble Insulation Brand do you Recommend?

Reader ERICA in WEST COLUMBIA writes: “Is there a specific bubble insulation brand you recommend? We will be using this as our vapor barrier in the roof. I’ve seen posts about this type of insulation disintegrating, so I’m wondering if the claims are exaggerated or if in fact it could be a certain brand. Also we are wanting to have cathedral ceilings throughout our building. Our roof is made with metal trusses and wood purlins. We are using bubble insulation and some type of batt insulation. What is the best method to vent if we are not going to have an attic space?”

To use batt insulation between roof purlins requires a minimum of an inch of continuous air flow between roof deck (roof steel) and insulation. To achieve this, you would need to add framing (such as 2×4 placed flatwise) running from eaves to ridge, then another layer running opposite direction. You could then use a reflective radiant barrier (bubble wrap) between overlays and batt insulation between purlins, up to depth of purlins. This requires vented eaves and a ridge vent.

Instead, look at spraying two inches of closed cell spray foam directly to underside of roof steel (between purlins), then fill balance of purlin cavity with unfaced rockwool batts. This will get you a higher R value and save on material and labor for a lot of 2×4. You should not vent either eaves or ridge in this case.

As for bubble ‘insulation’ – it is not insulation, at best (when completely sealed) it is an effective vapor barrier. There have been real problems with white vinyl facing of reflective radiant barriers flaking off over time. We had this same problem with our first supplier (and, of course, they went bankrupt before problems showed up). After selling millions of square feet, we stopped offering any reflective radiant barriers to our clients.

Read more about reflective radiant barriers here: https://www.hansenpolebuildings.com/2014/04/reflective-insulation-wars/

Ice and Water Shield with Threw Screwed Steel Roofing

Ice and Water Shield with Threw Screwed Steel Roofing

Making sense of Building Codes can be a daunting task, even for Building Officials. Post-frame construction is vaguely mentioned, at best, within Building Codes, leading to at best head scratching and at worst total confusion.

Ice and water shield is a waterproof membrane used to protect roof from ice and water damage. Its main purpose is to protect roof decking (plywood, oriented strand board – OSB, etc.) if water gets underneath roofing materials. Also known as a roofing underlayment, this rubberized slip-resistant product is “peel and stick” and self-adheres to roof deck’s surface, preventing it from flying up during high wind events.

Most post-frame buildings are constructed with threw screwed steel roof panels directly over purlins. So how do Codes apply to this circumstance?

2021 IBC (International Building Code) addresses Metal Roof Panels in Section 1507.4
“The installation of metal roof panels shall comply with provisions of this section.” (2021 IRC (International Residential Code) Section R905.10).

1507.4.1 Deck Requirements (IRC R905.10.1)
Metal roof panel roof coverings shall be applied to a solid or closely fitting deck, except where roof covering is specifically designed to be applied to spaced supports.” Metal roof panels on most post-frame buildings are designed to be applied over spaced supports (purlins)

1507.4.5 Underlayment (IRC Section R905.10.5) and High Wind.
Underlayment shall comply with Section 1507.1.1″ (IRC Section R905.1.1)

1507.1.1 Exception 3. “Structural metal panels that do not require a substrate or underlayment” (Note: this exception is not listed in the IRC, implying an underlayment must be used when V => 140 mph) Interestingly enough, the 2020 Florida Building Code, Residential, has an underlayment exception, “Compliance with Section R905.1.1.1 is not required for structural metal panels that do not require a substrate or underlayment.”

No substrate is required (steel fastened directly to purlins).
Table 1507.1.1(1) Underlayment Types (Table R905.1.1(1) in 2021 IRC)
Metal roof panels where maximum basic design wind speed V <140 mph are to be have underlayment per “Manufacturer’s instructions”

Manufacturer does not specify an underlayment must be used.
Metal roof panels where maximum basic design wind speed V => 140 mph are to meet ASTM D226 Type II or ASTM D4869 Type IV (IRC allows ASTM D4869 Type III)

ASTM D226 Type II is authentic asphalt saturated organic felt (also known as 30# felt) underlayment used as a breathable secondary weather resistant barrier when applied over roof deck prior to installation of primary roofing product.

ASTM D4869 Type IV affords same features as ASTM D226 Type II plus has a tear strength of 0.9 lbs/ft for both machine direction and cross machine direction of sheet; a 6% (as compared to 4%) loss on heating/behavior on heating for 5 hours at 221 degrees F; has liquid water transmission able to pass four hour water test on a 14 degree (3/12 slope) inclined roof; has a maximum dimensional stability of 1.75% both machine and cross direction from low to high humidity; has a 150% minimum saturation % by weight; a 2% moisture minimum % by weight at time of manufacture and a 70% minimum saturation efficiency % by weight.

However, we must refer in IBC governed buildings, once again, back to Section 1507.1.1 Exception 3 (yes, the Codes seemingly go around in circles).
1507.1.2 Ice Barriers (IRC R905.1.2)
“In areas where there has been a history of ice forming along the eaves causing a backup of water, an ice barrier shall be installed for asphalt shingles, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles, and wood shakes.”

Note: Metal roof panels are specifically not included.

Radiant Barrier, In-Ground Use Poles, and Sliding Door Replacement

This week the Pole Barn Guru answers reader questions about potential moisture issue when adding insulation to walls with a radiant barrier, advice about in-ground use poles, and replacing old sliding doors.

DEAR POLE BARN GURU: I have a pole barn on a concrete slab with footers. My 6×6 are anchored down and have a 2×6 plate down the perimeter of my living area. Foam under all the wood. I have radiant barrier on the outside of the walls 2×4 are over it then metal, so I have a air gap between the metal and radiant barrier. I’m adding R19 insulation it will touch the radiant barrier. And then drywall over the insulation. So you think Moisture will form under my drywall. I will have some air flow in my attic on top of my wall insulation it can breathe some.

Thank you. SONNY in MARYVILLE

DEAR SONNY: Your radiant barrier acts as a vapor barrier. In order to prevent moisture from being trapped within your wall cavity you will want to use unfaced batts. I would recommend rock wool, rather than fiberglass or cellulose, as it is unaffected by moisture. Do not add an internal vapor barrier or retarder (such as clear poly).

Having the radiant barrier forces your walls to dry to inside. If you did not place a well-sealed vapor barrier underneath your slab, you should seal it to minimize moisture coming up through your concrete. Depending upon how you have insulated and vented your attic space, you may need to add mechanical dehumidification to prevent mold growth.

You also should not have air flow from your wall into your roof, consider adding fire blocking in order to meet Code requirements https://www.hansenpolebuildings.com/2022/08/fireblocking-and-firestops/

 

DEAR POLE BARN GURU: Morning guru sir. I have been neck deep trying to plan our building. We are relocating to eastern Tennessee. A lot of people are saying to never put wood poles in the ground. What are your thoughts on this and how should I plan the foundation part of my build? It is a 2600 square foot single level with an almost as large garage. Thanks STEPHEN in CARVER

DEAR STEPHEN: I would have absolutely no qualms about using properly pressure preservative treated (UC-4B rated) columns in ground. Personally, my lovely bride and I live in an 8000 square foot finished, million dollar post frame shouse (shop/house) with embedded columns. I have also built (yes, me) two post frame buildings in Eastern Tennessee – one for my eldest son in Maryville (read about it here: https://www.hansenpolebuildings.com/2012/05/building-design-2/), the other in Happy Valley (an entire series of articles on this particular build begins here: https://www.hansenpolebuildings.com/2012/07/construction-time-2/). Both of these buildings used embedded columns and I predict these buildings will be standing long after my eventual demise (and will probably outlive my grandchildren and their grandchildren).

 

Horse ShelterDEAR POLE BARN GURU: I have a pole barn and need the outside sliding doors replaced. There are two doors and they’re each 10′ high, 8′ wide, and 1-2/3″ thick. Do you do this kind of work? ANDY in MIAMISBURG

DEAR ANDY: Thank you for reaching out to us. We are not contractors in any state and only provide materials for sliding doors along with our complete building kits. We would suggest you post this on your nearly Craigslist, under “gigs”.

 

 

Condensation, Floor Plans, and Planning a House

This Wednesday the Pole Barn Guru discusses condensation issues in a metal pole barn a reader would like to convert to livable space, floor plans for a new post frame residence, and the steps to take to plan and build a new post frame house.

DEAR POLE BARN GURU: I just purchased a property with a metal pole barn on it. It has a concrete floor and is not insulated. I want to finish part of it off to make living space. Currently condensation will form on the bottom of the roof and I obviously can’t have that over my living space. Planning to frame out the portion I’ll use for living space, install kraft faced batt insulation and then drywall over that. Not planning on any additional vapor barrier on walls. Once I build the ceiling I plan on using blown insulation. How do I address the condensation/moisture issue from the roof in the most economical way possible and do I need anything additional on the walls? The cement floor seems dry enough but I don’t know if there is a vapor barrier underneath, how can I know if it’s dry enough and if it’s not what should I do? Thanks so much!! MARK in UNDERWOOD

DEAR MARK: You can easily check your concrete slab for a vapor barrier – place a wrench on floor overnight, next morning remove wrench and if a dark spot is seen where wrench was placed, you have no vapor barrier. If so, seal slab with a high quality sealant (here is an example https://www.hansenpolebuildings.com/2018/11/siloxa-tek-8505-concrete-sealant/).
For you roof, best solution is two inches of closed cell spray foam applied directly to underside of your roof steel. If you create any dead attic spaces, make certain they are well ventilated, ideally at eave and ridge.

On exterior walls, since you have no Weather Resistant Barrier (Tyvek or similar), I would recommend using rock or mineral wool insulation (https://www.hansenpolebuildings.com/2013/03/roxul-insulation/) as it is unaffected by moisture. Install a well-sealed clear poly vapor barrier between wall framing and drywall.

 

DEAR POLE BARN GURU: Do you do 6 bedroom Barndo’s? I’m looking for a 6 bed, 4 bath barndominum floor plan. I have an idea of what I like in my head but 6 bedrooms one story are difficult. HEATHER in CLEBURNE

DEAR HEATHER: We can provide any number or bedrooms and bathrooms, as every barndominium Hansen Pole Buildings provides is 100% custom designed to best meet the wants and needs of our clients and their loved ones. Please see #3 here to assist in determining needed spaces and approximate sizes, and to have professional floor plans and elevation drawings produced affordably.

 

DEAR POLE BARN GURU: I would like to build a 20 foot wide x 40 foot long pole barn house in Fredericktown, Ohio. Do you know if the local building department would give a permit for a residential pole barn house, & what are the steps to obtaining that permit, who to call, & etc.? I’m at the beginning of that building process & would like to begin this summer. Thanks. RENEE in MOUNT VERNON

DEAR RENEE: Here is some information you may find useful in getting started: https://www.hansenpolebuildings.com/2021/02/a-shortlist-for-smooth-barndominium-sailing/
You will need to contact your local Planning and Zoning office to begin with. You can look up appropriate office (depending upon your actual Township/Village/City) at www.KnoxRegionalPlanning.com. This should get you what you need to know from them: https://www.hansenpolebuildings.com/2020/01/your-barndominiums-planning-department/
Many jurisdictions do have minimum square footage requirements for dwelling, so you may be forced into more than your desired 800 square feet. You may also want to investigate building 24′ x 36′ as it is more efficient for materials usage.

If anyone tells you a fully engineered post frame home cannot be erected in their jurisdiction, get from them a copy of any approved ordinance to confirm (usually there is not one) and if it does exist, get it to me and I will go battle for you for free (I win 99% of these).

In many smaller communities, Planning, Zoning and Building Departments are a “one stop shop”. Here is what we will need from your Building Department: https://www.hansenpolebuildings.com/2020/08/building-department-checklist-part-i/ and https://www.hansenpolebuildings.com/2020/08/building-department-checklist-2020-part-ii/

 

 

 

Rock Solid, Living Quarters, and Better Get an RDP

Today the Pole Barn Guru responds to readers questions regarding assistance in designing that is “rock solid for generations to come” using the reader’s own sawn lumber, a questions about adding a living quarter to an insulated building, and advice in bracing a post frame building better suited for a registered design professional.

DEAR POLE BARN GURU: Greetings, been following you on Facebook for a while and thought I’d reach out. I’m looking to build a pole building in Oregon, roughly 60×120, pretty flexible on designing and I’m sawing my own wood for the project, except for the trusses. I don’t need stamped engineered plans, I will be building it myself as an ag building that doesn’t require permit. However, I do need help with the design to make sure that its rock solid for generations to come. Is this something that you could help me with? Thank you in advance and kind regards. OMER in EUGENE

DEAR OMER: Thank you for being a loyal follower. Although I certainly have the ability to do your structural design, I prefer not as it would place me in a position of liability as well as practicing engineering without a license. Even though you are building a permit exempt agricultural building, I would encourage you to build from engineered plans – as you say you want it to be “rock solid for generations to come”. Only having it fully engineered is going to give you this sort of assurance. Sawing your own wood is also problematic https://www.hansenpolebuildings.com/2020/01/free-home-milled-lumber/ unless you have an ability to dry it to under 19% moisture content, surface (plane) it and have it grade stamped by a certified lumber grader.

 

DEAR POLE BARN GURU: I have a insulated pole building (sides and roof). I am framing in a small living quarter within the building and want to know if there are issues if I insulate the living quarters and should I put a vapor barrier on the inside framing? There is a 2″ gap behind the 2×4 wall and the current insulation/vapor barrier. I could leave the 2″ gap all the way to the attic or I can seal that, but assume best if I let the air gap breath. Attached is a picture. Look forward to your advice and thank you in advance. JIM in DEER PARK

DEAR JIM: If you were to leave this two inch gap open on top, it does defeat any insulation value potentially gained from having wall Metal Building Insulation. If you can tightly seal this air space, it will actually help to increase your heating/cooling efficiency. Should you do so, you should use unfaced rock wool/mineral wool batts and not add an interior vapor barrier. This will cause your space to dry to the inside, so mechanical dehumidification may prove necessary. Should you choose to leave gap open, you can used faced batts.

 

DEAR POLE BARN GURU: I have a 40″ side wall pole barn with rough cut red oak 6″ x 6″ posts on 8″ centers. The posts are bolted to engineered U braces that are secured in the concrete. The top of the posts have 2″ x 8″ rough cut red oak inside and out secured with through bolts. The bottom of the posts where they are secured to the u braces seem to me as a pivot point. Would “Y” bracing from the top down to about 4 foot to the center of each post be sufficient, or do I need to come down to the bottom near the U braces and run a board all the way across the 40 foot span and then 1 in the middle and “W” brace the side walls. I was thinking of keeping it open with the oak sealed with linseed oil or equivalent for looks, but could close in the sides. Thanks RUSS in STUARTS DRAFT

DEAR RUSS: Thank you for reaching out to me. Your dilemma should ideally be solved by a Registered Professional Engineer, however your build is going to add a degree of complexity and liability most engineers do not want to take on – ungraded rough sawn lumber. I would recommend you contact a few local engineers, as anyone interested in taking this on should come to your building site and do a thorough analysis of what you have. From this, they may be able to design engineered repairs for anything they find to be structurally inadequate.

 

 

Moisture Management, Poor Steel Cutting, and Info Help

Today’s “Ask the Guru” tackles reader questions about moisture management, poorly done steel cutting around windows and doors, and help “Looking for info” for Jack.

DEAR POLE BARN GURU: Hi, I am framing out an animal barn (right now to be used for housing chickens and storing some feed and hay) inside of an existing metal, wood framed pole barn.

The structure is near identical to what was described in this previously posted question here:

Insulating a Room in an Unheated Pole Barn

The only difference is that the roof itself is not insulated.

In the new interior room we will be adding fiber insulation between the studs (with a large gap between the exterior metal and the insulation), and a vapor barrier on the interior side, then the sheathing (likely plywood) interior surface. Then insulation, vapor barrier, sheathing on the ceiling/ floor of the “attic” storage. We are adding a vent in one exterior wall and one interior wall for air flow.

Is this approach sound in terms of moisture management? I’m unsure if this becomes an issue at the top of pole barn wall where we have an open roof overhang. There are also plans to heat the remaining area of the barn down the road.

Appreciate any help! HANNAH

DEAR HANNAH: If you have no vapor barrier under your concrete floor (or are unsure if you do or not) seal it to prevent moisture from coming up through it. I would recommend using unfaced rock wool batt insulation, as it is impervious to moisture. Do not use a vapor barrier in your ceiling.

 

DEAR POLE BARN GURU: Hello! I am in the process of building a pole barn that has several windows and walk-thru doors. As such, when I look closely at the exterior around these windows and doors, they look a little sloppily done where the metal siding meets up with the finish around the window and door openings. Is there a product that will help seal the 2 pieces of metal together as well as look nicer? I can provide a picture if you’d like. I was wondering if caulk is the way to go – or is there some double-sided sticky sealant foam type product that would work? Thank you! TRICIA in SUGARCREEK TWP

DEAR TRICIA: Yes, what you have was done very sloppily. Whoever built this for you should be replacing some panels to provide a much tighter fit between wall steel and J Channel around windows. While they are at it, here is how to create a leak free window: https://www.hansenpolebuildings.com/2020/03/no-leak-barndominium-windows/

 

DEAR POLE BARN GURU: Looking for info. JACK in MIDDLESEX

DEAR JACK: A great place for info is the www.HansenPoleBuildings.com website. Navigate to the upper right corner of the page and click on SEARCH, type in whatever term you want information on (e.g. BARNDOMINIUMS) and ENTER. Up will come relevant articles for you (there are over 2000 of them).

You may also want to get our helpful Planning Guide https://www.hansenpolebuildings.com/pole-barn-planning-guide/

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.

 

Convert to Residence, Insulation, and Truss Spans

Today’s Pole Barn Guru addresses reader questions about building upgrades to convert to a residential use, how to best insulate a monitor style building, and the possibility of trusses spanning 40′ to eliminate interior posts in a shop/storage building.

DEAR POLE BARN GURU: We bought a pole barn with no insulation, just studs and metal siding. We added faced batting insulation. But now we are thinking of making it a residential building. Do we need to remove the siding and put OSB and a vapor barrier house wrap on it? How do we refit this for a residence? KIMBERLY in COLUMBUS

DEAR KIMBERLY: No you do not have to add OSB and a Weather Resistant Barrier to your exterior walls.
Most pole barns are not designed to support wind and snow loads to extents required for residential applications – you should invest in services of a Registered Professional Engineer who can do a physical examination of your pole barn to determine structural adequacy and provide solutions for upgrades to make it safe for you to live in.

 

DEAR POLE BARN GURU: This has been covered 1 million times but I wanted to reach out directly! I’m in North Carolina. I have a 30×50 pole barn with a 20×50 lean to off both sides. The lean tos are accessible from inside the main shop. So imagine one large open space. Lean to walls are 10’ rising to 14’. Main shop is 16’ rising to about 22’ at the peak. I have bubble wrap foil under the metal on the roof. Open 2×6 ceiling. 2×6 walls with nothing on them but metal. I will add interior wall coverings probably in the form of 7/16 osb. Concrete has vapor barrier.

Buildings with loftsNow, I’ve been told to do closed cell insulation on my walls 1” thick. I wanted an opinion on whether to go every inch of the walls top to bottom all the way to the roof? Would I benefit from the insulation at all by just going to the 10’ mark (my lowest wall height) because that’s as high as my interior osb is going anyway. I guess what I am asking is it any benefit to insulate closed cell up to 10’ mark from the floor and then just bubble foil the main shop above 10’ to give a finished look? THOMAS in PLEASANT HILL

DEAR THOMAS: Unless you are planning on some degree of climate control in your building, there would be no real reason to make an investment into closed cell spray foam. If controlling interior temperature is a goal, then spend your money on insulation in your roof/ceiling where over ¾ of your heat loss/gain is coming from, before spending money on wall insulation.

 

DEAR POLE BARN GURU: We are looking to build a 40×90 pole barn, with 1/3rd being used for storage and 2/3rds for a vehicle maintenance. Both will be heated and storage cooled. Concrete floor, shingled roof, insulated, vertical metal siding, no windows, 5 overhead doors on the same side. Can you span the trusses from wall to wall and provide the above with no center columns? Thank you, ROD in CLEVELAND

DEAR ROD: Prefabricated metal connector plated wood trusses allow for some tremendous clearspan opportunities. We provide fully engineered post frame buildings with clearspans up to (and in some instances beyond) 80 feet. Your 40 foot width can quite easily be accommodated without any interior columns. One of our Building Designers will be reaching out to you Monday to further discuss your building needs.

 

A Conventional Foundation, Weather Resistant Barrier, and Moisture Issues

Today the Pole Barn Guru answers reader questions about building a “conventional” foundation, drainage between steel and shiplap siding, and potential moisture issues of stick built vs post frame foundations.

slab edge insulationDEAR POLE BARN GURU: I am building a 24X48 pole barn, but instead of using a slab, I would like to have a conventional foundation. Is there any advice you can give me on layout and construction using this method? ROBERT in FRENCH CAMP

DEAR ROBERT: We can engineer your building to be attached to a concrete, block or ICF foundation wall using wet set brackets. As an alternative, we can also provide a pressure preservative treated Permanent Wood Foundation. Details of your choice of system will be included on your fully engineered building plans, included with your investment into one of our building kits.

 

DEAR POLE BARN GURU: I am installing pole barn metal on a shiplap sheathed chicken coop/shop. Windows framed with J-profile trim. 8-foot walls with 2-foot eaves. Panels resting on treated 2x2s. Should I worry about water drainage behind the panels? Drain holes at bottom of panels?

Thank you. HAROLD in WELCH

DEAR HAROLD: You should probably place a Weather Resistant Barrier between shiplap and steel siding. As long as you seal windows well, you should not have any issues or need drain holes at bottom of panels.

 

DEAR POLE BARN GURU: I was confused with pole verse stick built structures. I thought that I needed to pour a concrete footer to put the building on to help give me a vapor barrier. Im placing this building in a area where I get some water and I wanted to keep it 8 inch on the perimeter. If I was to use a pole built would moisture come underneath into the building. JOSHUA in EDGEWATER

DEAR JOSHUA: Having a continuous footing and foundation will not act as a vapor barrier (but will add to your expense). Building Codes require a minimum 6mil vapor barrier under any concrete slab poured in a conditioned building (and we recommend using one under any interior pour). We normally recommend using thicker material (ideally 15mil) to help prevent damage during pouring slabs on grade.

If your site is in a location where water might collect or pond, your site should be built up with good, compactable fill to a level higher than any possible water depth (and some excess wouldn’t hurt).

 

Home Addition, Combo Building, and Moisture Barriers

This week the PBG answers reader questions about a post frame addition to a house, a combo business/residential building, and use of a vapor barrier.

DEAR POLE BARN GURU: We bought an older ranch house with a poorly done addition in the back. Since this dream property came with a house that prevents me building my dream barndominium, what are your thoughts on replacing this addition with a post beam constructed addition? if we pour a slab for the floor there would be about 2 or 3 steps down to the new room. it would allow for ground level indoor/ outdoor living, higher ceilings than the rest of the ranch, and give me just a bit of the open living space with exposed trusses that I’ve dreamed of. Carolyn

DEAR CAROLYN: Fully engineered post frame additions work well with pretty much any existing structural system. You also are not obligated to use steel roofing and siding, so it can be designed to match with your home. Another advantage is – you can do this sort of work yourselves, without having to hire it done!

 

About Hansen BuildingsDEAR POLE BARN GURU: Combination business and residential? Square footage of 7000. Can it be done? KEVIN in FLORISSANT

DEAR KEVIN: Interesting timing, as I was just going through some old family photos this week and found one of my grandfather in their grocery store from the 1930’s. My mother and grandparents lived upstairs from this store.

As for modern day combination business and residential, it can certainly be done using a fully engineered post frame building. Depending upon use classification of your business, it is likely you will be required to have at least a one hour fire separation between these dissimilar uses (really not any major thing – just a consideration).

 

DEAR POLE BARN GURU: Hello, I have a 24x50x8 pole building, concrete floor, and all metal is screwed directly to the wood framing. The purlins are spaced 2′ OC between the trusses, and I have 3.5″ closed cell rigid foam board to install between the 2×4 purlins. For the walls I have 1.5″ closed cell rigid board to install between the girts.

On the underside of the purlins after the closed cell rigid insulation is installed, I intend to install metal panels from the ridge to the walls. So, outside to inside it will be the following: Roof metal, then 2×4 purlins with 3.5″ rigid closed cell foam board in between, then metal panels installed on the interior. I will not have anything on the bottom chord of the trusses.

On the walls I plan to cut-to-fit the 1.5″ closed cell rigid foam board and install between the girts. After foam board is installed I intend to line all interior walls with painted OSB.

Question: based on the above, can I use vapor barrier (or plastic) between the interior metal and the 3.5″ foam board, and extend the vapor barrier down the walls between the foam board and the OSB? Or do you have another recommendation? COREY IN COULTERVILLE

DEAR COREY: You are far more ambitious than me, to cut and fit all those insulation boards to fit between purlins and girts. As it will be impossible to perfectly seal all of those joints between insulation and framing, it would be a good idea to install a well-sealed vapor barrier between insulation boards and steel liner panels. Keep in mind, you may end up with some humidity issues inside of your building (especially if there is no vapor barrier under your concrete floor), so you may need to have some sort of mechanical dehumidification.

 

 

 

 

Insulation Addition, A Clear Span Monitor, and Post Frame Code

This week the Pole Barn Guru discusses adding insulation to an existing building, building a monitor style building with a large clear span main level, and a building official misinforming a potential client.

DEAR POLE BARN GURU: I currently have a 30×50 Wick building on some property which I purchased last May. The building is 15 years old. It had a white faced batt insulation rolled out over the roof and wall purlins. The building is heated with a 80000 btu forced air furnace and has a 3.5 ton 16 seer AC unit as well. The building is used as a mancave/shop for piddling on projects. The design has an open ceiling. I would like to add additional insulation at the roof deck level. I have a local insulation contractor who has good reviews come and look at it. He is suggesting adding a 4″ thick x 24″ wide WMP50 batt insulation between the roof purlins. The research I have done suggests to not lay a batt over a batt as you could create an area where moisture cannot pass through. If the new vapor barrier of the WMP50 is sealed correctly would there still be an issue? I’d like to keep the open ceiling design as I currently have a car lift between two of the rafters and need to be above raise the vehicle cab above the bottom of the lower rafter horizontal. This kills the idea of putting in an insulated ceiling thus creating an attic space. Any thoughts on what the contractor wants to do as well as other ideas how to better insulate the roof?

Thanks… DAVE in MARSHALL

DEAR DAVE: You want to avoid having two vapor barriers. Easiest solution would be to poke holes in your existing white facing often enough to not create any two vapor barrier zones, then add your new product, making certain all joints between rolls are sealed.

 

DEAR POLE BARN GURU: Is it possible to have a monitor style barn to use the open upper level as a living quarters and not need support legs under to keep the lower shop level open. JOE in PUEBLO

DEAR JOE: It can certainly be done, and there are a few ways to get there.

second floorHere is how we did it for my Sales Manager, Dan, in my past life when I was a post frame building contractor. Dan wanted a 30′ x 50′ monitor style building for a garage/shop and then an office above. We had engineered a clearspan roof/floor truss combination for support of wings and second floor. This system had a double truss every 10 feet. At eight feet from each outside wall, we mounted columns to these trusses to support roof of raised center. Joists we placed for ceilings and floor system. With an 8/12 roof slope, upper level used scissor trusses with a 5/12 interior pitch.

For monitor buildings without as much front to back depth, we can design with parallel chord flat trusses used as girders and bury them in knee walls of raised center portion. This often precludes ability to have windows along upper level sides.

With post frame construction, if you can dream it, chances are good we can design it.

DEAR POLE BARN GURU: Hello, I am looking at building in Chippewa County, Wisconsin. I absolutely love the idea of doing a Pole Barn House/Attached Garage. The problem is that I cannot get an answer if I can build one in the county. The building inspector has been continually telling me that they cannot be built if the garage is directly attached.

I have attached a pdf of the floor plan for said building
Can you help with this? JEFF in STANLEY

DEAR JEFF: While your pdf did not make it, there is no reason you should not be able to have an attached garage, just as you could with any other structural building system. Building Codes certainly allow for attached garages (drive through any subdivision in our country), with appropriate fire separation between it and living spaces.

If your inspector persists, please ask him or her for a written copy of whatever ordinance this advice is based upon. Chances are good there is not one, and it is based upon some personal opinion. Should documentation actually be produced, please forward to me so I can go do battle for you.

 

 

 

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.

 

Site Prep,

Thursday’s edition will tackle three more reader questions. First up is about how level a site must be before erecting a shop, second is about pole barn homes and the many options available, and third is a question about the best method to fix an issue left by a previous builder.

DEAR POLE BARN GURU: I am planning on building a 30’x 40’ post frame shop. The ground is dirt and has about an 8” drop from east to west. How level must the site be before erecting the shop? I will out in a concrete floor after it is built. JASON in JACKSON

DEAR JASON: Personally I would get my ground as close to level before building as possible, as it is far easier to place and properly compact fill without your building being erected. Of all things being neglected in building construction, proper site preparation and compaction probably ranks close to list tops. You will want to read my series of articles beginning here: https://www.hansenpolebuildings.com/2011/11/site-preparation/.

Photos: https://hansenpolebuildings.com/uploads/polebarnquestions/0aaae906a4e86643f513e2c2c5b99bf1.jpeg

DEAR POLE BARN GURU: I saw a few pole barn homes on your website and was wondering if that is all the plans you have?  We are interested in wood siding, not metal. TRACY

Get A Free Quote!

DEAR TRACY: Every post frame building Hansen Pole Buildings provides is 100% custom designed to best meet your wants and needs. We encourage our clients to design homes to best fit their lifestyle. By working from inside to out and not trying to fit what you need within a preordained box just because someone said using a “standard” site might be cheaper you can arrive at an ideal design solution. Differences in dimensions from “standard” are pennies per square foot, not dollars.

You can use the links in this article to assist with determining needed spaces, sizes and how to get expertly crafted plans and elevation drawings: https://www.hansenpolebuildings.com/2019/10/show-me-your-barndominium-plans-please/

If you find an existing plan somewhere you feel will meet your needs, we can adapt it to post frame construction and save you money. Hansen Pole Buildings can provide fully engineered post frame buildings with any type of siding or roofing materials.

 

DEAR POLE BARN GURU: I am working on finishing an apartment above a garage with framed walls/OSB and steel on the roof. The contractor who walked off the job did not put any type of vapor barrier between steel and purlins. I priced closed cell spray foam which is more than homeowner wants to pay. I was then thinking about using Visqueen on the ceiling (bottom cord of standard truss) with unfaced insulation for an airtight vapor barrier. But after more research it looks like that may not be a good option. There is ridge and soffit venting. What do you think? If not Visqueen or faced insulation do you think one inch of closed cell on the metal and batted down on the ceiling would work in Pennsylvania or would just an inch still allow sweating?

DEAR JOSHUA: Exasperating when contractors cheap out and leave clients (or client’s next builder) with a mess to have to fix.

You have only a couple of realistic options – first one is ugly, remove roof steel and place a thermal break between conditioned space and roof steel. This could be as simple as adding a Reflective Radiant Barrier. It never comes back together as well as it did originally, and when all is said and done, option number two will be less expensive.

Option two is closed cell spray foam. It really takes two inches to be an effective vapor barrier, and should run roughly two dollars per square foot of roof surface. While homeowner might not want to make this investment, he or she did not do their homework to initially be an informed buyer and if they do not solve this challenge it will be a problem forever.

 

Plans Only? Moisture Barriers? and Two Story Houses?

This week the Pole Barn Guru answers questions about “plans only” purchases, proper use of moisture barriers when adding insulation to an existing building, as well as the possibility or building a two story post frame house.

DEAR POLE BARN GURU: Do you offer just the plans? I own a sawmill and would like to mill my own lumber for my project. With the exception of the trusses. I can also source the metal roofing locally. THERON in WALDEN

Engineer sealed pole barnDEAR THERON: Thank you for your inquiry.

We are unable to provide just plans as it becomes a liability issue for our engineers – it takes away insuring materials specified actually end up being delivered to your building site.

 

There are also issues with attempting to use home milled lumber: https://www.hansenpolebuildings.com/2020/01/free-home-milled-lumber/

As an example, in sourcing your own metal roofing locally, even if steel quality was equivalent, they will not be able to provide powder coated diaphragm screws to attach it.

DEAR POLE BARN GURU: Purchased property with existing fairly new pole barn. Question is regarding wall insulation. Some installers say use double backed 6 inch glass rolls insulation under my drywall. Then I spoke with another & he says mandatory to spray closed cell foam or condition will ruin insulation…..there is no vapor barrier wrap on outside. Any help would be appreciated. Thanks, DAN in GRANBURY

DEAR DAN: You should have some sort of barrier between wall framing and wall steel to prevent condensation within the wall cavity. Wall cavity moisture can lead to a plethora of challenges – premature rusting of steel siding, rot, mold and mildew on wood framing and lack of performance of fiberglass insulation.

 

You could remove wall steel and add a Weather Resistant Barrier (highly labor intensive and things never go back together as well as they were originally assembled), or do a two inch coating of closed cell spray foam, then use fiberglass inside of it.

Here is my Ultimate Guide to Post Frame Building Insulation: https://www.hansenpolebuildings.com/2019/11/post-frame-building-insulation/

DEAR POLE BARN GURU: Hi there! I was wondering if y’all do two story residential pole houses? Second question, if I sent you guys a rough sketch of a blue print would you guys be able to give me an estimate off of that? (with included trim choices and such)

Thank you! MAX

Gambrel roof pole barnDEAR MAX: I happen to live in a two story post frame shouse (shop/house) with a partial third story. Back in the great state of Washington, I also have a three story post frame building with roof top deck! We can provide any low rise building with up to 40 foot tall walls and three floors (or 50 feet and four floors with sprinklers).

 

Send us what you have and chances are very good we can get you an estimate from it (we might want to ask you a few questions about what you intend to build).

 

Contact Information, Moisture Barrier, and Insulation

Today the Pole Barn Guru answers questions about contact information to build a structure, whether or not to use a moisture barrier in a non-conditioned attic, and guidance to insulate a post frame building.

DEAR POLE BARN GURU: Hello, I have a quick question, do you have any regional contact information for people to build these barns?  Thank you,

EARL in LOWER MICHIGAN

DEAR EARL: In many areas Hansen Pole Buildings can provide contact information of one or more possible contractors to erect buildings. We can let you know in advance if your area is one or not, however we will not provide names and numbers until after you have invested in a new post frame building kit package from us.

Why?

As much as we would like to believe otherwise, not every client or contractor is morally trustworthy. We have provided builder information to potential clients and had these same wonderful clients try to get builders to go around us and cut a better deal for their building materials. Conversely, we have had builders tell our clients to buy everything direct from them and they will get a better deal.

When either of these situations occur, clients are shortchanging themselves as they are not getting a genuine third-party engineered Hansen Pole Building. We hear about these when problems occur (they almost always do) during construction and clients call our office looking for help! My sympathy level for these people is very low, as they have gotten themselves into their own predicament – generally with disastrous results. Often times these same builders fail to see Building Permits are obtained, or neglect to call for required inspections. Or, builders will provide non-engineered and under design buildings – prone to failing under snow or wind loads far below minimum standards.

If it sounds shady, it probably is.

DEAR POLE BARN GURU: Mike, thank you for all the great info…

If I build a pole barn with attic storage and insulate only the walls and ceiling with blown in cellulose such that really only the interior ground floor space is insulated (and it will be heated in the winter), should I still worry about condensation on the roof sheet metal up in the attic, since the air up there should be at a similar temperature to outside? (There will be soffit vents and a ridge vent for attic air flow)
IE, do I need the bubble wrap material, or is it then unnecessary if the attic space is uninsulated?

Thanks! JESSE in CLEVELAND

DEAR JESSE: Thank you very much for your kind words!

Absolutely, you should be concerned about attic condensation. Warm moist air from inside your conditioned space will rise into attic and when it comes in contact with your building’s roof steel’s cooler surface it will condense (even with ventilation). For sake of ease of construction I would recommend an integrated Condensation Control Membrane (https://www.hansenpolebuildings.com/2014/07/condenstop/ ). It will be slightly more expensive for materials than a Reflective Radiant Barrier, however time saved should make it well worth your investment.

 

DEAR POLE BARN GURU: In central KY, would it be best to have outside metal, then house wrap on the girts, then plastic vapor barrier, then have blown or fiberglass insulation in the walls, then install metal interior? Is this the correct order or would this be wrong? Also on the ceiling and roof, would you put house wrap under the metal roof, then insulate directly against roof from inside, or just insulate directly on top of the ceiling, which would be metal, like the interior walls? Thank you!! BRAD in LEXINGTON

DEAR BRAD: Here is my definitive guide to post frame insulation: https://www.hansenpolebuildings.com/2018/06/pole-barn-insulation-oh-so-confusing/

In your case – you want moisture to be able to pass out of your wall cavity, so any vapor barrier needs to be on inside directly behind your finished wall surface material. House wrap (Weather Resistant Barrier or WRB) is not a vapor barrier. If installed directly under your roof steel it will allow warm moist air to pass through and you will have condensation between WRB and steel. Not good.

Directly between roof steel and purlins use one of these:

Properly sealed Radiant Reflective Barrier, Steel with Condenstop or Dripstop factory applied, 30# felt or Ice/Snow Shield over plywood or OSB, or (if none of those previously mentioned) two inches of closed cell spray foam. Me, I’d vote for Condenstop/Dripstop as it is a relatively low investment and easy to install. Blow in insulation on top of your ceiling.

And think hard about steel liner panels – they are more expensive than drywall, they reflect sound, there is a potential for condensation from your ceiling and it is difficult to attach things to walls (shelves, cabinets, work benches, etc.).

 

 

Addition to House, Stone Floor Moisture Barrier

Today the Pole Barn Guru discusses a post frame addition to a house, whether or not one should use a plastic barrier under the stone floor in a steel building, and the ability of a truss carrier to handle imposed loads.

About Hansen BuildingsDEAR POLE BARN GURU: Hi! We are considering a sizeable addition to our 600 sq ft bungalow style home, somewhere in the neighborhood of 30×40 ft addition. Wondering if it’s possible to do pole barn construction for this addition, and what kind of considerations would need to be made? The current home does have an existing basement with block foundation. I’ve read information regarding attaching a pole barn build to an existing house for use as a garage, but wondering how this scenario changes things? We would work with a licensed designer to draw up plans, and a licensed contractor for the build, but are just in the brainstorming phase at this point. KARI in WILLMAR

DEAR KARI: There are actually no real considerations for post frame not applicable to a stick frame building. You should work with a Hansen Pole Buildings designer for your building shell and we can provide engineer sealed plans for structural portions of the addition. You can work with an independent designer (FYI – there isn’t a category of licensing for designer) or create an interior layout of your own.

DEAR POLE BARN GURU: Should I put plastic down under the stone floor in a steel building? BOB in WYALUSING

DEAR BOB: It certainly would not harm anything and will help to minimize condensation issues. Look at a 15ml thickness. For more information on vapor barriers see: https://www.hansenpolebuildings.com/2017/11/vapor-barriers-slabs-grades/

 

DEAR POLE BARN GURU: Really wondering if a 2×12 SYP MSR 2400 will hold my 32ft trusses 2ft oc poles 6×6 8 oc. 1 2×12 on outside and 1 on inside. Is the 2×12 SYP MSR 2400 strong enough to hold the weight? CHRISTOPHER in CHESTERFIELD

CHRISTOPHER: In answer to your question – maybe. It will depend upon a myriad of factors including (but not limited to) Ps (roof snow load adjusted for slope), Dead loads from roofing, any roof sheathing, truss weight, any ceiling or insulation.

If you are so inclined, you can try this calculation yourself:

complex formulaLOAD (in psf – pounds per square foot) X (½ building width plus sidewall overhang in feet X 12”) X Distance spanned by beam squared (in feet)

Divide this by 8 X 2400 X 2 (for two members) X 31.6406 (Section Modulus of a 2×12) X 1.15 (Duration of Load for snow).

If your resulting answer is less than 1 then your beams will probably work.

Caveats – LOAD is Ps + all dead loads. For steel roofing over purlins 5 psf would be my recommendation. If a ceiling is to be installed a minimum of 5 psf should be added (10 psf being better).

Some important factors other than just strength include deflection (especially if trusses support a gypsum wallboard ceiling), minimum required bearing area and shear force at edge of bearing.

Frequently overlooked is connection of beams to columns. Notching in would be preferred to each face of columns.

Ultimately, RDP (Registered Design Professional – architect or engineer) who provided your sealed plans should be making a determination as to adequacy as well as providing appropriate connections.

 

Blowing Attic Insulation

Blowing Attic Insulation, Without Vapor Barrier, Below Roof Steel

A very common problem I see involves people not preparing their post frame (pole barn) buildings to adequately be insulated.

Reader NED in THURMOND writes:

“Thank you for your help. I’m in process of completing a pole barn project. It’s divided into three sections…living area, workshop, and garage. The size is 24 x 44. The outside perimeter wall is 2×6 frame with OSB and metal on the bottom and metal only in the top portion. The wall cavity is filled with unfaced insulation and poly on the inside. The roof is 8’ oc trusses with metal panels and no moisture barrier. 6 mil poly was applied to the ceiling joists. I wanted to insulate the ceiling, so I removed the poly and plan to install Sheetrock and blow in R-38 overhead. The building has a ridge vent and soffit vents in the eaves. Do I need a moisture barrier on the ceiling or will the blown in insulation suffice? What, if any problems do you anticipate? Thank you so much.”


Mike the Pole Barn Guru responds:

Here are some anticipated problems –

Without some method of condensation control beneath your building’s roof steel you are going to have moisture problems. Blown in fiberglass or cellulose insulation will lose their effective R value once they get wet. A practical solution will be to have closed cell foam insulation sprayed upon roof steel underside. Normal recommendation would be two inches thick however your local applicator(s) can give you their best input from experience. Make sure spray foam does not block either eave air intakes or ridge exhaust points. You can create a “dam” at eaves to keep blown in insulation from filling soffits, by use of ripping high R closed cell insulation boards. Again, make sure not to block incoming airflow (you need a minimum of least one inch of free area above insulation boards).

Planning a new post frame building? If so, I encourage you to take appropriate steps for your building to have future insulation installed. Yes, there will be some initial investment involved.However it will be so much less expensive to plan for it now than to wish you would have later.

 

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.

 

 

Spray Foam Insulation with Dupont Tyvek House Wrap

Hansen Pole Buildings Designer Rachel asked me about this today:

“I have more and more builders say they put Tyvek® on the walls and roof and then spray foam.  This is so they can replace the siding/roofing in the future.  Do you find any downfalls with this?  I thought this was a pretty good idea.”

Having just written an article about spray foam insulation (https://www.hansenpolebuildings.com/2016/07/advantages-spray-foam-over-batt-insulation/), this is a well timed question.

Tyvek and all house wraps are NOT (I repeat NOT) vapor barriers. They are weather barriers: https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/.

Spray-Foam-Insulation-150x150In doing my research on the whys and why-nots I found apparently there are some spray foam insulation contractors who will not spray foam against house wraps, apparently from not being able to guarantee their product would properly adhere to the house wrap.

In one particular case – the spray foam insulation contractor tried to persuade the client to use BIBS® insulation (read about BIBS® here: https://www.hansenpolebuildings.com/2011/11/bibs/) due to the potential adhesion issues.

There apparently is an adhesive additive for spray foam, which will assist in the foam being able to stick to house wraps or other slick surfaces.

As closed cell spray foam is a vapor barrier, and is resistant to moisture passing through it in either direction, adding a weather barrier to the outside becomes redundant.

If the idea is to use a product to allow for easy residing or reroofing, then a product such as clear visqueen (https://www.hansenpolebuildings.com/2013/07/moisture-barrier/) might prove to be as effective, as well as less costly than a weather barrier. This is, of course, providing the spray foam installer is willing to spray over it.

As a good, high quality steel roofing and siding should last the life of the building – installing any product between it and the siding, under the premise of making future replacement easier, it sounds much more like someone trying to make a feature into a benefit, than it does something which will add value to the client as a benefit!