Tag Archives: closed cell spray foam

Avoiding Condensation When Insulating an Existing Pole Barn

Avoiding Condensation When Insulating Existing Pole Barn

The last thing people want to have to deal with would be condensation dripping in their pole barn. When an originally unheated cold storage building becomes repurposed to be climate controlled, possible condensation poses some new challenges.

If you are reading this article and plans are to construct an unheated building, I implore you to consider taking steps so it could be repurposed to be heated and/or cooled later. Please browse through some of my previous articles regarding this subject, such as: https://www.hansenpolebuildings.com/2018/06/pole-barn-insulation-oh-so-confusing/.

Reader JOSEPH in ALPINE writes:

“We have a pre-existing pole barn that we want to turn into a insulated building. Knowing that condensation would be a problem, I’m looking for a professional to consult with so it is done correctly. Is this something you do and what are your rates?

 

The building is 15×15, on a pad. There is no attic- 1/4” plywood is nailed to the ceiling 2x4s. We’d like to keep this height since it affords space for a loft. There is a single central roof vent. I read your response to one customer about using unbatted insulation on the walls and punching holes in the plastic to allow venting. But how does one allow for venting when there is no attic space? Our main house (1937 farm home, remodeled to modern code in 2003) is a metal roof with the upstairs rooms opened up, no attic, no roof vents. How can one replicate what is done in the house with this pole barn?

Thanks.”

Mike the Pole Barn Guru writes:

I am deeply flattered to have someone offer to hire me for a consultation. Here is my response to Joseph:

I am a bit geographically inconvenient to be able to come and see your building. However, based upon experience and what I would do if it was my own building, I will give you some free advice. You are welcome to use it, or discard it as best you see fit.

As you do not know if a vapor barrier exists beneath your existing concrete slab, I would use a high quality surface sealant over it. Your major water source for potential condensation will be through this slab. I’d close off roof vent, and have inside surface of siding and roofing closed cell spray foamed. Your local installers can give you recommendations for thickness, however I would not go with less than two inches thickness. If possible or practical, unfaced fiberglass insulation may be added to the inside to increase R value. However, it might be most practical to just pay a little extra for thicker spray foam.

 

 

The Advantages of Spray Foam Insulation in Pole Barns

The Advantages of Spray Foam Insulation in Pole Barns

Spray foam insulation is an all-in-one solution that can effectively regulate temperature, reduce noise, and prevent moisture in your pole barn. Although all types of insulation minimize heat transfer, spray foam is the only material that can also seal against air leaks, potentially resulting in energy savings of up to 20%. Spray foam insulation is a liquid foam that hardens to form an air and vapor barrier made up of numerous tightly-packed air pockets or “cells” that are resistant to heat, sound, and moisture transfer. The foam also expands up to 30-60 times its original volume before it cures, so it can fill air gaps that traditional insulation materials can’t so easily reach. Spray foam insulation can therefore lower your heating and cooling bills and transform your pole barn into a comfortable and functional living space.

Temperature control

Spray foam insulation tends to regulate temperature better than other types of insulation. Closed-cell spray foam, in particular, has an impressive R-value of around 7 per inch (R-value is simply a measurement of how well a material reduces the flow of heat). And that’s a far higher R-value than most. Just take a look at other popular insulation materials in comparison — fiberglass batts provide around R-2.9 to 3.8 of insulation per inch, while stone wool batts provide R-3.3 to 4.2 per inch on average. The reason for closed-cell spray foam’s effectiveness is its unique structure: the interior cells within the foam remain fully closed and densely packed, which makes it harder for heat and air to flow through them. Alternatively, open-cell spray foam is still a fairly good insulator compared to other materials — providing roughly R-3.5 of insulation per inch — although it isn’t as powerful as closed-cell spray foam. As the cells in open-cell spray foam remain open and aren’t completely sealed, it’s a softer and less dense material. It therefore doesn’t regulate temperature quite as well as its closed-cell counterpart. In terms of price, spray foam insulation is a relatively expensive option, with closed-cell spray foam costing around $1-$1.50 per board foot (144 cubic inches) on average, whereas open-cell costs between $.045-$0.65 per board foot. However, the energy savings provided should offset that initial cost in the long-term.

Noise reduction

Spray foam insulation can also effectively reduce the amount of sound that gets in and out of your pole barn. The barrier created by the interior air pockets in both open- and closed-cell spray foam insulation successfully absorbs noise and minimizes sound transmission. Of course, without adequate insulation, the sound of wind, rain, and nearby traffic can sometimes be a problem inside pole barns due to their metal roofs. So, the noise reduction provided by spray foam insulation is an important benefit for most people, particularly if you need your pole barn to be a calm and peaceful living or working environment. Alternatively, if you use your pole barn for noisy activities (such as, music practice, woodwork, or metalwork) effective soundproofing with spray foam insulation is just as important to prevent noise pollution seeping through to the outside.

Moisture prevention

Closed-cell spray foam insulation also forms a strong vapor barrier that can keep moisture and mold out of your pole barn. Surprisingly, air leaks are actually the biggest reason moisture gets into buildings, accounting for “98% of all water vapor movement in building cavities”, the U.S. Department of Energy reveals. That said, it’s still important to prevent the problem of slow moisture diffusion, which is responsible for the remaining 2% of moisture problems. Closed-cell spray foam insulation can help here as it’s an effective standalone vapor retarder that simultaneously works to prevent the flow of moisture, air, and heat. Open-cell spray foam, on the other hand, is generally too light and airy to be able to form a strong vapor barrier. So, if you do opt for open-cell spray foam, you’ll also need to invest in additional vapor barrier coatings to adequately control moisture levels in your pole barn.

Spray foam insulation — and particularly closed-cell spray foam — is a great choice for your pole barn. It’s an all-in-one solution that effectively regulates temperature, reduces noise, and keeps out moisture to ensure your pole barn stays as comfortable, quiet, and energy-efficient as possible.

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)

Why Are You Stuck on Bookshelf Girts?

Why in World are you Stuck on Bookshelf Girts?

Reader JAMES writes:

“Why in world are you stuck on bookshelf girts. For instance with ‘normal’ pole barns one could SPF the walls and roof and have almost no heat loss through the lumber. One could argue your “bookshelf girts” and purlins between trusses makes the building VERY close to a “normal home”. Do you offer a traditional style built pole barn as there MUST be savings to be had.”

Mike the Pole Barn Guru writes:
There are as many ways to structurally design post-frame buildings as there are providers and builders. Our way of building happens to be very similar to what would be considered as traditional style in Western states such as Washington, Idaho, Oregon, California, etc.

We do happen to offer buildings with columns every eight feet, trusses every four feet – however very few clients ever pick this as an option.

We are always looking at ways to make our post-frame buildings more efficient and DIY friendly, without sacrificing performance.

Worst part of post-frame construction (and least easily to detect challenges in advance) is having to dig holes. By widely spacing columns (usually most cost effective is every 12 feet), number of holes having to be dug is reduced by roughly 1/3rd from eight foot spacings.

Let’s examine R-value, calculated using Type 1, conventional method.

For sake of discussion, we will use an 18 eave height (tall enough for two stories in most instances). I’ve chosen a flash and batt method, for sake of cost effectiveness of insulation.

R-value through cavity

Air film – inside 0.67

½” gypsum wallboard – 0.56

2” closed cell spray foam – 14

5-1/2” Rockwool – 23

Exterior cladding – 0.5

Total R = 38.73

R-value through girts

Air film – inside 0.67

½” gypsum wallboard – 0.56

2×8 girt – 9.06

Exterior cladding – 0.5

Total R = 10.79

On an 18’ wall, there will be 8 girts with an area of 1.5” x 12’ x 8 = 9.6 sft (Square Feet)

Total area of a bay = 18’ x 12’ = 216 sft

Hence girts makeup 9.6 / 216 = 0.044 (4.4%) of wall

10.79 x 0.044 + 38.73 x 0.956 = 37.5

37.5 / 38.73 = 0.968 (96.8% of a wall without girts)

How about pieces in say a 60’ long wall?

Your “traditional”

Splash planks:  1/12’ 3/16’

Girts: Exterior 2×6 8/12’ 24/16’ Interior 2×4 8/12’ 24/16’
NOTE: Exterior girts may fail in deflection, especially at wall corners where forces are greater

Columns (excluding corners): 7/22’

Truss carriers (will vary depending upon roof load): 2×12 2/12’ 6/16’

Me:

Splash planks: 5/12’

Bookshelf girts: 2×8 40/12’

Girt blocking: 2×4 10/16’

Columns(excluding corners): 4/22’

Your version has me handling 74 pieces of lumber, with 1582 bd.ft. (board feet) of lumber vs. 59 pieces with 984 bd.ft. of lumber

Your wall sets outside of external wall girts at Building Line and creates an 8-1/2” thick framed wall. On a 40’ wide building, net framed interior clear width is 38’7”.

My wall has outside of columns at Building Line, so only 5-3/4” is lost on each side. Net framed interior clear width is 39’0-1/2”

In summary, my being stuck on bookshelf wall girts loses only 3.2% to thermal bridging, reduces holes to be dug (per sidewall) by 43%, reduces pieces to be handled 20% and board footage of lumber used by 38%, while delivering a greater net usable interior space.

Best Practice for Closing and Insulating 2×10 Headers

Best Practice for Closing and Insulating 2×10 Headers
Reader DAVE in VIROQUA writes:

Best practice for closing and insulating 2×10 headers. My pole barn has building wrap then closed cell spray foamed walls. Ceiling not yet installed but want to use blown in fiberglass with vapor barrier. The spray foam on walls goes up to the bottom edge of the outer header. Before the ceiling is installed and insulated what is your suggestion to close and insulate the double 2×10 header to prevent moisture issues etc.? My walls will be finished off at a later date. Building has vented soffits and ridge vent. Roof panels have drip guard on underside as well. The post framing is laminated 2×6-3ply. Thank you.”

Mike the Pole Barn Guru pens:
One of my pet peeves of what I refer to as 4 & 8 buildings (trusses every 4′, columns every 8′) is when truss carriers (headers between columns) are applied to column faces, rather than being notched in. Rarely are fasteners sufficient to be able to resist loads imposed by those once every hundred years snow storms, resulting in roofs lowered to top of vehicle levels. 

Besides connection challenges, it further reduces actual amount of usable interior space. As an example, builders/providers will set outside of exterior (barn style) girts at Building Lines, and to finish interior requires adding yet another set of face mounted wall girts. This ends up with wall framing 8-1/2″ thick. On a 24′ wide building, if 1/2″ gypsum wallboard is used, interior finished dimension ends up being only 22’6″!

In answer to your question, you’ll want to enclose above double 2×10. This can be done by cutting strips of whatever low cost sheet good you can find (OSB, plywood, etc.) and installing them between trusses on top of truss carriers. Fill cavity between 2x10s with closed cell spray foam.

Hopefully you will not have issues with your current closed cell spray foam applied to a weather resistant barrier. Best practice is to spray directly to inside of steel (please read more here https://www.hansenpolebuildings.com/2020/04/spray-foam-insulation-3/)

Retrofitting for an Interior Workshop

Retrofitting for an Interior Workshop

Loyal reader LAURI in NORTH BRANCH writes:

Thank you ahead of time for your generous gift of answering these questions. I love your blog. I have a 40 x 60 pole barn and doing an interior workshop of 25 x 40. Exterior walls (only in workshop area) have no vapor retarder and have R15 in Owens Corning pink board topped with 3/4″ plywood. I put in a tin ceiling (in the workshop area only) with no vapor retarder. I have not insulated the attic area above the workshop yet. It is well ventilated with eave and ridge vents. I put in a 2 x 6 partition wall which will separate the workshop area from uninsulated storage area. I will infrequently be using some form of AC on the hottest MN days and only occasionally use some form of heat (forced air, Mr. Heater or torpedo heater) to heat the workshop. The floors are sealed but without a vapor retarder under the concrete. I’m torn on what to do with the partition wall insulation. Vapor retarder or no Vapor retarder on the shop side? The interior shop wall covering will be 3/4″ plywood and the storage side will be OSB I have on hand. I’m thinking a wool product for minimizing any potential for mold. What insulation should I use for the attic space at truss chord level? I think you lean towards a blown in but can I leave the underside of the roof uninsulated? Vapor barrier or no vapor barrier on interior partition wall? What questions am I not asking that I should be? Thanks again for your wisdom. Nice to feel that someone has our interests at heart. Wish I would have found you guys before I built. Maybe a second one will be in our future where we can pay back the kindness.”

Mike the Pole Barn Guru says:

Thank you for your kind words, they are greatly appreciated.

My goal is to always try to assist people from making crucial mistakes they will regret forever.

My concerns for your workshop area are going to be ones of moisture – although your slab on grade has been sealed, it has no vapor barrier underneath, so you are probably yet going to have moisture passing through. Heating with either propane or kerosene will be adding even more moisture into this area. 

 

I would look at design solutions allowing moisture to pass out of your workshop, and not in. For those interior walls, unfaced Rockwool batts, with a housewrap on the cold storage side of studs. Ceiling, if you can find it, use blown granulated Rockwool, as it is unaffected by moisture. Otherwise use Rockwool batts, overlaying layers 90 degrees to each other.

If you have no thermal break between roof purlins and roof steel, you are likely to have some condensation challenges, even if well ventilated. Keep a close watch and if you see condensation beginning to form, have two inches of closed cell spray foam applied to the underside of roof steel, otherwise it will rain on you.

Thinking Stick Frame Rather Than Post Frame

Thinking Stick Frame Rather Than Post Frame

Reader BRAD writes:“Real question…I’ve been doing lots of reading and love this site. I am building a 40x60x14 this spring. I originally thought I was going to go pole barn and now I am thinking stick frame. Reason….1. I am going to have insulated concrete foundation with in floor heating piping installed right away. (mono slab). 2. I am planning on fully finishing the inside insulation electrical, etc. in the future. What I’ve seen with post frame is that they are cheaper to build initially but if you are planning on finishing the inside there is substantial lumber and framing that needs to be done for interior walls and interior ceiling. It appears “at the end of the day” a finished pole barn is not much cheaper than a stick frame. I also question if it would be a lot more time trying to frame an interior post frame with 16” o/c studs and finishing a ceiling with 4’ or longer truss spacing vs 2’ with conventional stick frame. I am doing all metal exterior with 2’ o/c stud purlins on side walls vs osb sheathing. I know you can spray closed cell spray foam but again that is more than triple the price vs bats and vapor barrier that you can only do with 24”or16” o/c framing. 

Am I way off base on this theory or is there any truth to my thinking?”

Mike the Pole Barn Guru responds:
I just don’t see reason number one as a reason at all. A plethora of post frame buildings (my own included) utilize radiant in-floor heat. In order to stick frame, you are going to have to thicken your slab edges, or pour a continuous footing and stem wall, in order to provide adequate support for your now load bearing walls. This is going to result in added expenses for forming, regardless of your choice (before even considering extra concrete required). While anchor bolts for stud walls are relatively inexpensive, they do require some effort to be properly placed in order to avoid hitting studs and plates need to be drilled to account for them.

In order to stick frame without added engineering, your wall heights are going to be limited by Building Codes. To attach steel siding, you will need to add horizontal framing outside of your studs (scarily, I did see a builder post photos of vertical steel siding, screwed to vertical studs), resulting in two sets of framing, extra pieces to handle, cut and install. By using commercial style bookshelf wall girts in post frame, no extra framing is required in order to attach exterior steel siding and wall finish of your choice. As post frame buildings transfer gravity loads from roof-to-ground via columns, eliminating (in most instances) any need for structural headers.

Using prefabricated metal connector plated wood trusses, in pairs, directly aligned with columns (most often placed every 12 feet), does require ceiling joists to be placed between truss pairs. This can all be done on the ground, then cranked into place using winch boxes, with no need for other heavy lifting equipment.

When all is said and done, fully engineered post frame construction will always be more cost effective than stick frame, more structurally sound and afford a greater ability to super insulate, regardless of one’s choice of insulation systems.

Looking for Advice on Insulating My Pole Barn Walls

Looking for Advice on Insulating My Pole Barn Walls

MATTHEW in CENTRAL ILLINOIS writes:

“Hello! I am a member of the Facebook pole barns and buildings page and see your post with advice often. I honor your opinions. I am wondering if you can help me out. I have a 30×48 pole barn in central Illinois. Concrete floor.  I don’t believe there to be a moisture barrier under the concrete. I am wanting some advice on how to finish the inside. I’m thinking about doing bookshelf girts instead of interior girts attached to the poles. Should I use 2×4’s or 2×6’s? My thought is 2×6’s, but should I put them up against the exterior girts, or away from them to allow a space for insulation? There is no house wrap or vapor barrier on the inside of the metal. I would like to heat it as needed during the winter, but only when I’m working on a project. I wouldn’t have continuous heat. What insulation would be safest to use to prevent moisture along with being somewhat affordable? I do have a place about a half mile away that sells factory seconds of various foam boards. I have also heard good things about rock wool. Spray foam seems to be the most popular, but also can be more expensive. What are your suggestions taking in consideration of no current vapor barriers, location, and intermittent usage? “


Thank you for reaching out to me. Please message me any time with questions.

If unsure of whether there is a vapor barrier under your concrete slab, start by sealing it.

Here is how: https://www.hansenpolebuildings.com/2019/02/how-to-properly-apply-post-frame-concrete-sealant/

This sealant came highly recommended: https://www.hansenpolebuildings.com/2018/11/siloxa-tek-8505-concrete-sealant/

2×4 #2 bookshelf girts should be stiff enough on your small span between columns to prevent undue deflection of interior finishes, as well as limiting thermal transfer. Hold them flush to the inside of existing wall columns.

I would look to fill your insulation cavity with Rockwool batts, with a well-sealed vapor barrier on the interior.

Condensation Challenge, Adding a Garage Door, and Barn Movers

This week the Pole Barn Guru answers reader questions about likely condensation challenges with a closed envelope in coastal South Carolina, an addition of a 16′ wide garage door to an existing building, and if the Guru knows any pole barn movers in central Illinois.

DEAR POLE BARN GURU: I want to keep my building a closed envelope, for conditioned attic space. 40x60x12. My plan is to use closed cell foam 2″ on walls and 3″ on roof deck applying directly to the metal. Do you foresee any moisture issues? Environment is coastal South Carolina, Georgetown county. Hot and humid, very rare to see sub-freezing temps. Also what kind of HVAC do you recommend? RON in GEORGETOWN

DEAR RON: Unless you are going to mechanically dehumidify, expect to see condensation challenges.

Your site is in Climate Zone 3A, where the 2021 IECC (International Energy Conservation Code) specifies minimums as R-15 continuous for walls and R-49 for ceilings. You could achieve this by just over 2″ of closed cell on your walls, however you would need to add another R-28 to your roof. This could be done by adding unfaced Rockwool (Rockwool is not affected by moisture) batts between roof purlins. Specify 2×10 roof purlins 24 inches on center, then use just over 2-1/2″ of closed cell plus 23″ wide x 7-1/4″ Rockwool batts.

Your HVAC provider can recommend a system most practical for keeping humidity at manageable levels.

 

DEAR POLE BARN GURU: Can you add a 16 ft wide garage door to an existing pole barn? It would be on a gable end of a 30×50 building. ALEC in TOLEDO

DEAR ALEC: Probably, however it should only be done with a structural review from a Registered Professional Engineer as you would be dramatically reducing shear capacity of your endwall.

 

DEAR POLE BARN GURU: Do you know any pole barn movers in central Illinois? Have a 52×100 we would like to move about 15 miles, ambitious I am sure. MELANNE in DAWSON

DEAR MELANNE: If I had to take an educated guess, I would say it will cost more to move that it would to build new from scratch. At 52′ feet wide, it would take every road being at least four wide lanes between start and end of trip. You can Google “house movers near me” to see if there is anyone in your area.

Why Fiberglass Insulation Doesn’t Work

Why Fiberglass Insulation Doesn’t Work

This article includes information in italics from a paper from Rastra.com, a provider of ICFs. For those interested, to read their paper in full please visit: https://www.rastra.com/docs/sales/Why_fiberglass_insulation_doesnt_work.pdf

I have been scouring insulation, vapor barrier and building envelope sources for months now, trying to get to truthful data I can rely upon. Let me tell you – it has been a task, and there are moments when I felt blood would squirt from my eyeballs!

“Fiberglass insulation is considered the standard in new construction. Unfortunately, fiberglass has serious flaws. Some of these may surprise you.

Let’s begin with this… it’s a little known fact that fiberglass insulation loses as much as 40% of its insulating capacity when outside temperatures fall below 20 degrees F. When this happens, R-19 fiberglass insulation performs as if it were only R-9. LEED confirms through a Canadian cold weather study that fiberglass loses half its R-value below 0 F. When you need it the most fiberglass insulation cannot properly insulate.”

While fiberglass insulation may lose some small percentage of R value in cold temperatures, this Oak Ridge study is very old news and no longer is pertinent (please read more here: https://www.hansenpolebuildings.com/2021/10/blown-in-fiberglass-attic-insulation/).

Andre Omer Desjarlais at Oak Ridge Laboratories was contacted about this issue, and he said, “This was true 20 years ago but all fiberglass manufacturers have changed their products appreciably since then and this is simply no longer an issue.”

I have searched high and low and cannot find this supposed Canadian cold weather study.

“Fiberglass also performs poorly in the presence of humidity within a wall cavity higher than just 30%. In winter this leads to condensation of moisture carried in by warm air through leaks through the wall. This raises humidity levels inside the building.”

This paragraph frankly makes no sense. I am finding no studies to back up fiberglass insulation performing poorly in high humidity. Condensation in walls can by minimized or eliminated by a well-sealed interior vapor barrier and/or using a flash and batt system with appropriate ratio of R value of closed cell spray foam applied to interior of siding, compared to batt insulation. Ratios are determined based upon the Climate Zone. If using flash and batt, mechanical dehumidification is necessary as walls will dry to the inside of the building.

“Once fiberglass insulation becomes damp its performance decreases dramatically. In fact, it only takes a 1.5% increase in moisture content in fiberglass to reduce its R-value by up to 50%. When moisture is trapped in a conventional wall cavity insulated with fiberglass and sealed with a vapor barrier, insulation becomes damp and loses its ability to insulate. This also promotes mold growth and leads to structural damage.”

I love “it fact” especially when I cannot locate any research to back it up! Regardless of insulation type, just keep wall cavities dry by use of properly placed Weather Resistant Barriers between framing and siding and well-sealed interior vapor barriers/retarders (when using batt insulation and not closed cell spray foam).

“Yet another problem with fiberglass is that for it to work it must be fully expanded to allow its air pockets to perform.”

From Bruce Harley (energy efficiency expert at Conservation Services Group), “When you compress fiberglass insulation, you increase its R-value per inch, up to a pint. However, when you compress a batt of a particular thickness, the total R-value does decrease. For example, standard low-density batts at their nominal rated thickness – R-19 at six inches – have an R-value of about 3.1 per inch. If you compress a 6-inch R-9 batt into a 3-1/2 inch cavity, you get about R-14, or 4.0 per inch.”

“Lastly, fiberglass wall insulation is designed to be used in framed walls. Everywhere a framing member is placed creates a thermal break between the pieces of insulation that allows air to pass. If 2x4s are used to construct the wall anywhere a 2×4 is positioned the wall only has an R-value of R-3.5. On average 27% of a building’s exterior wall’s surface is made up of 2×4 framing members with an R-value of only R-3.5.”

Assuming 2×4 studs at 16” on center, a stick frame wall would be roughly 10% not 27% (27% would take studs under six inches on center). In post frame construction with 2×8 bookshelf girts 24” on center, on a 10’ tall wall only 5% of wood members contact both interior and exterior surfaces, with 2×8  girts having an R-8.7 (per Green Building Advisor). Balance of the cavity could be filled with R-22 of fiberglass or R-30 Rockwool.

Calculating assembly R-values from ASHRAE:

Weather Resistant Barrier = .17
Interior Air Barrier = .68
½” gypsum board = 0.45

((1/22) x (.95)) + ((1/8.7 x (.05)) = .0489 = 1/.0489 = R20.4 + 1.3 = R-21.7 with fiberglass

((1/30) x (.95)) + ((1/8.7 x (.05)) = .0374 = 1/.0374 = R26.7 + 1.3 = R-28 with Rockwool

Moral of this story, fiberglass does work, however it may not be your best design solution.

Poor Project Planning Makes for Poor Results

Poor Project Planning Makes for Poor Results.

I am feeling WESLEY in DULUTH’s pain as he describes his situation below:

“Hello! I have a question regarding insulation and condensation. The picture shows a cathedral style ceiling with 12 inches of space between the tin and bottom of framing. My plan is to use R-38 fiberglass batts spaced from the tin by one inch. The roof is vented with two foot vented soffits and vented ridge cap. I would install a 10 or 15 mil vapor barrier then ¾ poly sheet foam and drywall. Spray foam is out of my budget so not really an option for me. There is no WRB under the tin due to poor project planning. Do you see this causing condensation issues or is there a better solution? Thanks.”


Mike the Pole Barn Guru:

While you may not like my answer, I always tell it like it is.

Without a thermal break directly between roof steel and framing you will have condensation issues, there are no two ways around it. A WRB (Weather Resistant Barrier) would not have helped your situation, as it would allow moisture to pass through and be trapped between it and your roof steel – likely resulting in premature deterioration of your roofing.

You could do:

(a) Remove roof steel and install something – least expensive being a well-sealed Reflective Radiant Barrier; next up being well-sealed Metal Building Insulation (horrid stuff to work with https://www.hansenpolebuildings.com/2011/11/metal-building-insulation-in-pole-buildings-part-i/ and https://www.hansenpolebuildings.com/2011/11/metal-building-insulation/) or solid sheathing (plywood or OSB) with 30# felt (90# if slope is under 3/12) or a synthetic ice and water shield.

Any of these would solve your condensation issue, however it creates yet another problem – trying to insulate and have an inch of unobstructed air flow from eave to ridge above insulation. Not going to happen.

Or

(b) Have two inches of closed cell spray foam applied to the underside of your roof steel, then fill the balance of cavity with unfaced rockwool batts (https://www.hansenpolebuildings.com/2013/03/roxul-insulation/).

Your idea of using fiberglass batts will result in them getting wet from condensation, losing R value and becoming a home for mold and mildew. While spray foam may be out of your budget, the expense of fixing something done wrong will make it sound cheap.

Help! My Barndominium Vaulted Ceiling Drips

Help – My Barndominium Vaulted Ceiling Drips

Reader HOMER in PIEDMONT writes:

“I called in today and was referenced to send an email – 

I have come across your website and have gained a vast amount of knowledge – I was hoping to get some more information on my situation – I also understand that you actual don’t sell insulation and that any advice you give me might not benefit your business – I am willing pay a consulting fee if you like or if i can purchase any products through your company that will help me get out of this pickle i will be more than happy to – 

So my situation (the pickle) 

I built a 30×60 barndominium with vaulted ceiling (the purlins on top are 8″) i used about 1/2″ to 1″ of closed cell spray foam all over it then laid the typical pink batting insulation in it – the issue I am having is I am in Oklahoma – on a morning of a cold night – when the sun comes out it heats the metal roof up and creates condensation – hence a ceiling that rains throughout the day – it seems to happen closer to the peek more than the bottom portion of the ceiling 

I have tried pulling some of the batting insulation out of the middle section to help create more air space – it did seem to help a bit but still saw condensation on the spray foam insulation – when i removed my test panel (also i used 3/8 bead board for my interior sheeting) 

On the peak of the roof I didn’t use the foam vent ridge cap but filled it in with spray foam (I was going for air tight) which might be more of the issue 

I truly am sorry to bother you with this issue and any help or direction would be greatly appreciated – please reach out via email or phone and I am sorry if I didn’t give enough detail to paint the picture that I am facing.”

Mike the Pole Barn Guru says;

Thank you for reaching out to us. Our goal is to assist our clients from making crucial (and often costly) errors they will regret forever. While your circumstance is crucial, it can be rectified.

According to Johns Manville, a minimum of 1-1/2″ of closed cell spray foam is required in order to provide an adequate air and vapor barrier (we have always recommended two inches, as we feel it is better to be safe than sorry). Right now, the underside of your closed cell spray foam is cool enough on those cold mornings so warm moist air rising inside meets it and condenses. This is more pronounced as you approach interior peak due to warm air rising.

If it was my own roof – I would remove all fiberglass roof plane insulation, increase thickness of closed cell spray foam to at least two inches, then fill balance of 2×8 cavity with either open cell spray foam or rock wool batts (rock wool is not affected by moisture and does not lose R value during cold temperatures).

Only other possible solution (have not tried, so is only hypothetical) would be to mechanically dehumidify the interior of your barndominium to a degree low enough to eliminate your challenge. This would probably need to be under 20% relative humidity – so low as to become uncomfortable to live in (Dry, itchy skin & eyes) and causing shrinkage of wood in floors, cabinets, doors and furniture.

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).

Think About Barndominium Insulation BEFORE Building

Think About Barndominium Insulation BEFORE Building

Regular readers are probably beginning to wonder why I have so many requests for information on how to insulate buildings AFTER they have been erected.

Me, too.

Insulation is crucial to your barndominium’s long term thermal performance. Doing it wrong can be expensive, both up front, as well as over lifetime of heating and/or cooling.

Reader JAMES in MILTON writes:

“Hello, I could really use your advice. I’m having a 48′ x 48′ wood barn built in Georgia with a 1,200 square foot apartment/ loft on the second floor. The purlins on the barn will be 8″ thick with 24″ spacing (center to center). The barn’s ceiling will be attached to the bottom (interior) side of the purlins. Plywood, the roofing underlayment, and the metal roof will be installed to the top (outer) side of the purlins. I’m looking to put insulation in-between the purlins to achieve (as close to) an r-40 insulation rating. Originally, I was going to get 2″ r-10 foam board insulation and layer them in between the purlins (up to the 8″), but prices for form board insulation increased again in my area and is having me rethink my plan (went from $40 to $60 a sheet). Plus, I would have to cut each foam board to fit in between the purlins, which is time consuming. I’m considering other options, but really don’t have the construction background to know which direction to go. From what I’ve read online, my setup would be an unvented space, limiting my options to spray foam (closed cell), foam board insulation or structural insulated panels (which goes on top of and not in between the purlins). I’ve also read I could install a layer of closed cell spray foam inside the purlins cavity but against the underside of the plywood. Afterwards, fill the rest of the purlin cavity with an air permeable insulation, such as faced fiberglass batts insulation. But I’m not sure if this option still requires venting. What is the best option when installing insulation in between purlins? Would foam board insulation work well? If so, other than cutting to size, would I have to do anything else? Thank you in advance for your help.”

Mike the Pole Barn Guru says:

Welcome to challenges of trying to get adequate insulation when finishing the underside of roof purlins.

Fulton County is Climate Zone 3A. 2021 IEEC requires ceilings to have a minimum R-49 – going to be tough to get unless you were to closed cell spray foam on the entire cavity.

You could do 2″ of closed cell spray foam directly to the underside of your roof deck (R-14), then fill the balance of the cavity with unfaced rockwool batts (roughly R-17). You do not want a vapor barrier below batts as this would trap air between two vapor barriers. Kraft facing on fiberglass batts is a vapor barrier and fiberglass is negatively affected by any moisture (even 1.5% moisture content can reduce R value by 50%).

Foam board will be highly labor intensive, difficult to air seal, provides a lesser R value than the same thickness of closed cell spray foam and at $60 a sheet, is approaching price of spray foam.

Another option would be to fill the cavity with unfaced rockwool batts (roughly R-23) then add two layers of 2″ R-10 foam board below purlins before your interior finish. It might be difficult to source rockwool batts 7-1/4″ thick, so may require doubling 3-1/2″ batts.

Saving a Poorly Designed Crawl Space

Saving a Poorly Designed a Crawl Space

Reader GEORGE in VIENNA writes:

“I am substantially replacing rotted parts of an existing building set on short 6×6 treated posts which are in good condition. above the posts it is conventional platform construction, and untreated. Unfortunately, the original builder set the building partially into the side of a hill in an attempt to use thermal mass and reduce energy use in its off-grid location. The uphill side was backfilled to a height of approximately 30″ above the interior floor, which is OSB over untreated 2×12 beams and untreated 2×6 joists. Skirting to keep out moisture was untreated plywood, poly sheet, and Styrofoam block insulation. In 6 years, there is substantial rot of the perimeter plywood, perimeter 2×12 rim joists, some 2×6 floor joists, some areas of the OSB flooring, the untreated sole plate and a few studs above. Otherwise the building walls, windows, doors, roof trusses, metal roof, insulation, etc., are well made and in good condition. We are temporarily supporting the building from below and removing the failed materials all the way around. We are removing the backfilled dirt on three sides to expose the posts and provide airflow underneath. All rim joists, beams, and floor joists will be replaced with treated materials. I am looking for advice in two areas (1) floor insulation, either under or over the OSB, and (2) treated skirting around the perimeter which would allow partial backfill and maintain ventilation.” 


Mike the Pole Barn Guru says:

You really have two options:

You could condition your crawl space – this would require a 6mil or thicker, well-sealed vapor barrier to cover underlying soil and up perimeter walls to floor joists. There would be no vents with this method, however an air-circulating device must be provided. Perimeter walls should be insulated using either closed cell spray foam or rock wool batts. 

From Building Code Section 308.3, Unventilated Crawl Spaces

The air-circulating device must move at least 1 cubic foot of air per 50 square feet of crawl space area. The crawl space floor area must be completely sealed with a vapor-retarding material. The edges of the vapor retarder must be lapped up against the inner foundation walls.

Read more about encapsulated crawl spaces here: https://www.hansenpolebuildings.com/2020/11/11-reasons-why-barndominium-crawl-space-encapsulation-is-important/
Or – have an unconditioned crawl space, where your vapor barrier would cover the ground surface. Insulation would ideally be beneath OSB – between floor joists. Again, same choices for insulation – just between joists. With this choice foundation vents would need to be added to perimeter walls.

Most building codes require 1 square foot of open ventilation area for every 150 square feet of crawlspace. Generally, Automatic Foundation Vents have 50 inches of net free area per vent. Therefore, install one vent for every 50 square feet of crawlspace.

FDN (Foundation) rated pressure preservative treated plywood will probably be your best skirting material.

Closed Cell Spray Foam Adhesion

Closed Cell Spray Foam Adhesion to Dis-similar Materials

Reader GREG in ASHEVILLE writes:

“How long will closed cell foam maintain adhesion/air barrier function to dis-similar materials (sheet metal and lumber in the case of post frame)? I ask because my experience with foam is limited to what was sprayed beneath my floor/floor joists (estimating late 70s to early 80s). The bottom of the floor joists has a membrane to hold the foam in place. When the membrane is not present, the foam can be seen as laying on the membrane/no longer attached to the wood joists/sub-floor.

I love the concept of post framing w/ foam, seems like this saves on materials and labor needed for construction. We are currently looking to build our last/retirement house, and I believe the foam will outlast me, but when it’s time to sell will the next owner have a problem with the air sealing? 

What are your thoughts?”

Mike the Pole Barn Guru responds:

In my humble opinion, engineered post frame construction is truly an answer for material, labor and energy efficient low-rise buildings (up to three stories and 40 foot tall walls or 4 stories and 50 foot with fire suppression systems).

https://hansenpolebuildings.com/2022/01/why-your-new-barndominium-should-be-post-frame/

I have researched your adhesion concern and have been unable to find any closed cell spray foam ‘coming loose’ instance.

SPF adheres to various construction materials including metal, wood, and concrete very well. However, licensed installers must ensure surfaces are completely dry, and oils, grease, dirt, and debris free as outlined in code-referenced application standards.

It is also important to assess weather when applying spray foam. While the  product may be applied in various climatic conditions, it is important to follow manufacturer’s recommendations and its Evaluation Listing installation limitations. Sprayfoam and related coatings should not be installed when there is ice, frost, surface moisture, or visible dampness present on the surface to be covered. Surface moisture can react with SPF chemicals resulting in poor-quality foam and/or adhesion lacking.

SPF system adhesion is a key field test and licensed installers are required to conduct a field test series for adhesion and density on every project, every chemical lot change, and every eight hours. These tests are conducted using field test kits installing contractors must have on their spray rigs. Test Result must be recorded on daily worksheets and submitted to their third-party certification organization for review and retention.

In some SPF insulation installations, substrate surface priming may be required, especially when applying foam to large metal surfaces. Primers can greatly enhance adhesion between SPF and existing substrates. Primers can help seal porous substrates and improve adhesion to metal substrates.

Can No Longer Afford Spray Foam for a PEMB

Can no Longer Afford Spray Foam for a PEMB

Loyal reader CINDY in TYLER writes:

“I had a steel building (20×18)  built with steel frame and metal exterior. This is going to be my house. It will have a loft that is half the size of the building. Originally the builder talked me into spray foam and that’s what Ii planned to do. He said I had to use wood to frame inside the metal walls first, then run electrical and plumbing before the spray foam. That was a couple of years ago. Now that inflation has caused prices to soar, I am simply not able to afford the spray foam. My main concern is the condensation/moisture issue. i am doing the rest of the work by myself. Since I don’t have any help it’s not going to be feasible to remove wall panels to install house wrap or insulation. So I wanted to get your expert advice on how to handle this. Specifically I have a plan to run by you. So the idea is instead of building my framing inside the metal frame, move to the inside of the metal, attach wood frame to the inside edge of the metal frame. Insulate the inside of the wood frame and add a moisture barrier to the inside of the wood frame before drywall. I will lose 3.5″ of space all around the inside but i think that will take care of any moisture issues. Please tell me what you think about this plan and make any appropriate suggestions even if you don’t post this on your blog. Also I wanted to thank you for the wealth of knowledge you have readily available on your site. Can’t tell you how much help you have been.”

Mike the Pole Barn Guru responds:

Thank you for your kind words, they are greatly appreciated.

Normally (in your climate zone of 2A) I would be recommending closed cell spray foam as insulator of choice – due to a combination of heat and humidity. Your builder headed you in a correct direction.

Before we get into how to frame your interior, we need to address what is going to happen with your roof. With steel installed directly over framing (whether wood, or in your case steel), if there is no well-sealed thermal break, you are going to experience condensation issues. You are going to have to find a way to spring for two inches of closed cell spray foam sprayed directly to the underside of your roof steel. Steel frame and steel purlins should also be sprayed. If not, you are going to have condensation on them – steel is a wonderful conductor of heat and cold.

Now – on to your question at hand. For your walls, it appears most folks do exactly as you propose and build a 2×4 wood stud wall inside of their PEMB’s (pre-engineered metal building) steel wall girts. You will want to completely fill your wall cavity with insulation – I would recommend rock wool, as it is not affected by moisture (here is information on one particular product https://www.hansenpolebuildings.com/2013/03/roxul-insulation/). You want to make sure your interior vapor barrier is extremely well sealed, including outlets.

If you do not have a well-sealed vapor barrier under your slab on grade, please seal your concrete now. Your HVAC system should be designed to mechanically dehumidify, else condensation is going to haunt you forever.

My 22 Year Old Morton Building Roof Leaks

My 22 Year-Old Morton Building Roof Leaks

Reader TERRY in EVANSVILLE writes:

“Dear Pole Barn Guru, we have a 1989 Morton building. The roof was replaced in 2000 due to flaking and peeling paint. Since then, the headers over our large north and south doors have deteriorated, and the barn is leaking on the entire stretch of north and south walls further deteriorating the wood at the top and consequently the bottom as it runs down. I believe this has been happening since the roof was replaced …taking this long for us to notice the damage. I was told that there is a condensation problem. But, water runs from the ridge to the eave. We can see stains on the trusses. There are two places where water has dripped in the middle of the barn. I went up on the roof and inspected the ridge. Appears as though the ribbed metal has been over tightened about every 2 to 3 ft. in a 140 ft. span. In light rains we do not see water running down the walls, in heavy blowing storms, the water runs enough that I have videotaped it. Any words of wisdom or insight to what you think is going on would be greatly appreciated. I’ve been dealing with Morton since March of 2020 with not much success. Also, just a side note… one of their people stopped by in 2016 to look things over…at that time he said he could not adjust the doors. But…gave a $10000 estimate to rebuild, instead of looking into why there was a problem. I think if we had done the repair we would be facing a similar problem today, as the problem seems to have grown worse. Thank you in advance!”

Mike the Pole Barn Guru says:

You could have a plethora of different issues going on.

Start by process of elimination –

Is there a form fitted closure strip under each side of your ridge cap? If you have light coming through the ridge during daylight, then no. Easiest fix, if none, would be Emseal https://www.hansenpolebuildings.com/2016/03/emseal-self-expanding-sealant-tape-closures/

2) Check for leaks. Get a garden hose up on your roof – start by running water at eave lines and have someone inside yell when a leak is found. You only have to do this test on a small portion along your eave line. Pick a spot where interior water stains are greatest. Gradually work your way towards the ridge line. Leaks can usually be fixed by replacing the original screw by one of longer length and larger diameter.

3) Once the above two have been either ruled out or repaired, your problem is condensation. Stains on trusses and purlins are typically a giveaway to this being an issue, especially if they seem relatively consistent from eave to ridge and along length of building. Short of replacing roof steel with a product with an Integral Condensation Control factory applied (read more here: https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/), your solution is not inexpensive – have two inches of closed cell spray foam applied directly to underside of your roof steel.

Questions from a Future Barndominium Owner

Reader JASON in WINDSOR writes:

“What are ways to avoid a stone base for slab to protrude under grade board using a post in the ground or pier with wet set brackets? We want grass to grow right up to the building’s base rather than stone around the perimeter or stone flower beds. I don’t like the idea of moist soil on treated grade board. Also have questions in regards to fascia trim provided by Hansen’s kit. Tried to ask the sales rep and he couldn’t answer. With packed is the fascia trim two piece application? Meaning one that covers soffit material on bottom of fascia board and one that overlaps bottom piece acting as drip edge. In Kevin Hart’s build and kit review video he claims Hansen only provides one piece and it goes on after roof metal is on leaving wood exposed. I’m thinking he’s missing a piece or step. Lastly the infamous questions of spray foam on roof. Tyvek or straight to metal? Thanks in advance.”


Mike the Pole Barn Guru says:


For those reading along at home, you may want to grab a tub of popcorn and watch Kevin and Whitney Hart’s video review: www.youtube.com/watch?v=sYGF1YY_yZQ

There are several ways to avoid having your slab’s stone base from coming out from beneath your grade board (aka splash plank). If this building is to be heated or cooled, you are in Climate Zone 4. 2021 International Energy Conservation Code (IECC) requires slab perimeter insulation for climate zones 3 and higher. This can be achieved by use of rigid board EPS (expanded polystyrene) R-10 insulation (and keep your stone where it belongs). Inside of your splash plank attach insulation boards so the top is 3-1/2″ above the bottom of the splash plank. You can then use this to screed your slab from. Climate zones greater than 3 require this to be four feet in depth, however you can go two feet deep, then out horizontally following https://www.huduser.gov/publications/pdf/fpsfguide.pdf

Grade boards (splash planks) are pressure preservative treated to UC-4A requirements and should not experience premature decay issues when in contact with moist soil. We can provide Plasti-skirts to cover them, keeping soil away entirely. https://hansenpolebuildings.com/2017/08/plasti-skirt/.

On fascia trims, we’ve used a plethora of different variations before settling on our current model. We do use a one piece fascia L trim, sized so it entirely completely covers the fascia board, there is no exposed wood. With properly placed inside closure strips at the extreme downhill edge of fascia, we have never experienced water getting behind fascia L trim. We did try a shorter height L fascia trim, with an eave trim and found the angle of eave trims caused drip edge of eave trim away from fascia trim. When screws were placed thru eave trim to prevent this – eave trims puckered out away from fascia trim between screws.

Closed cell spray foam is best applied directly to roof or wall steel. https://hansenpolebuildings.com/2020/04/spray-foam-insulation-3/

Please reach out to me any time with questions.

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.

Retro Installing Windows in a Spray Foamed Post Frame Building

Retro Installing Windows in a Spray Foamed Post Frame Wall

Reader JOEY in PRINCETON writes:

“Good Evening Pole Barn Guru! We need to add picture (9) and slider (3) windows to an existing 3-year old Sherman Pole Building Post frame building where we are converting part into living quarters. The building was spray foamed by the previous owner with closed cell foam, and upon some investigation (and confirmation by the builder – Sherman Pole Buildings) house wrap was not used. We need to order the windows for spring installation and are wondering how and what kind of windows to use. A salesman at Menards flippantly recommends using windows with a nail flange without brickmold. To assist our carpenter who will do the installation (with my assistance) I have searched high and low on the internet for a way to install the windows, but all I find are instructions on installation before steel is installed, and nothing with regards to existing spray foam insulation that is adhered to the steel. We realize we will need to scrape the foam insulation, so we are ready for the work involved. What advice can you offer? Do you have a window vendor to recommend? It would be greatly appreciated. I’ve attached pictures for your reference, Thanks for all your help.”


Mike the Pole Barn Guru says:
Joey is finding some challenges involved when it comes to doing a conversion from a barn to living quarters. Most post frame barns and accessory buildings are not engineered for residential structural requirements and unless one is 100% confident they have been appropriately engineered, a Registered Professional Engineer should be engaged to do a thorough site inspection and advise as to adequacy or structural repairs/upgrades.

I have given your situation a great deal of consideration, trying to weigh all involved factors of costs of materials, labor involved and end result. Here is what I would do:

In each bay (area between two columns) where an opening needs to be added, I would completely demo wall. Remove all insulation, girts and siding. I’d order replacement steel panels, install new girts, framing in new window openings, etc. New vinyl windows should be ordered with integral J Channels (sometimes referred to as J trim attached). These can be from any manufacturer and should be gas filled Low-E windows. Personally I feel it worth opting for triple pane windows in our climate. Going this demo and rebuild route will allow for sloped sill pans to be placed and self-adhesive flashing tape to be utilized.

In defense of your ‘Big Box’ salesperson – box stores and lumber dealers are unable to compensate help well enough to acquire, train and retain truly knowledgeable help.

Trying to scrape off your existing closed cell spray foam cleanly would be at very least a daunting task and is likely to damage some or all of your panels being scraped. Your only way to cut steel to properly fit windows snugly takes removal of steel panels, full length, as they need to be slid into place alongside windows.

Barndominium Closed Cell Spray Foam

Barndominium Closed Cell Spray Foam – and Rodents

Closed cell spray foam applied directly to steel roofing and siding can be a great product for controlling condensation, achieving an air tight barndominium and at R-7 per inch is a great insulation solution. So good, I strongly encourage its use, especially for those buildings in Climate Zones one and two (deep South).

One thing it does not do is to prevent mice, rodents and other similar pests from enjoying your comfortable living spaces.

It’s important to understand what it is inviting critters in to begin with.

Where your barndominium has most air leaks is where rodents, bats and bugs come in through. Usually this is poorly detailed and installed steel trims.

When these pests are looking for a nice, comfortable place to stay, they are going to run along outside barndominium’s exterior until they find an opening. Basically, these rascally little rodents are looking for air movement out of your barndominium. 

If it’s cold outside and your barndominium is leaking heat, a mouse is going to find those leaks and consider it as a warm invitation in!

Seal up any openings where these critters can get into your barndominium, especially if you notice openings in your roof or along wall steel base. Those are issues you’ll want to take care of right away.

Once this is done, adding closed cell spray foam insulation can help.

Spray foam offers no food value to rodents or pests. 

Good thing about closed cell spray foam when it comes to pests is it does help to seal up those cracks and crevices where it is sprayed, making it more difficult for those unwanted guests to get inside. This is because closed cell spray foam creates an air seal keeping inside air where it belongs.

As creatures search for drafts coming from your barndominium, closed cell spray foam’s air barrier leaves nothing for those varmints to find.

Closed cell spray foam insulation is in no way a repellant. As mice, bats, rats, and other pests can chew through wood to get into and out of your barndominium, they can of course chew through closed cell spray foam.

 

Closed cell spray foam insulation in your barndominium can definitely help keep pests out as it provides a defensive layer to keep pests out by blocking those air leaks they are looking for.

Texas Post Frame Barndominium Insulation

Reader KIMBERLY in LINDEN writes:

“We are building a 52x40x10 post frame home in East Texas.  The entire thing will be living space.  I have been researching as much as possible on the best way to insulate a post frame home with metal siding and roof.  The information is overwhelming and you get a completely different answer depending on who you talk to.  I know not to skimp on insulation, but the consensus on most “barndominium” FaceBook groups is that spray foam is the only way to go.  I have reservations about that, because it may be a superior way to insulate, but it depends almost exclusively on who is doing the actual foam application.  On top of that you need to spend more money on your HVAC system to add the proper ventilation/air exchange.

I want a well insulated home that is specific to the type of building material and location we live in.  To me, “not skimping” on insulation doesn’t mean that it has to be the most expensive insulation either.  

I also know the insulation world is constantly changing and evolving, but what would your recommendation be to insulate our home in East Texas?

Thank you so much for your time!”

Mike the Pole Barn Guru responds:

Your insulation requirements will vary depending upon where you are in East Texas. Climates zone 1 (closest to Gulf) require R-30 ceilings, R-13 walls. Zone 2 requires ceilings to be R-49 and zone 3 (farthest north) goes to R-20 walls. You can look up you county’s climate zone here: https://codes.iccsafe.org/content/IECC2021P1/chapter-3-re-general-requirements#IECC2021P1_RE_Ch03_SecR301. I will cheat for you and tell you Cass County is Climate zone 3A.

For sake of discussion we will assume you have a dead attic space and will be insulating directly above a finished ceiling.  I would ventilate your dead attic space at the eave (air intake) and the ridge (air exhaust). Make provisions for preventing condensation on the underside of roof steel by having some sort of a thermal break. My personal preference is by using an Integral Condensation Control (https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/).  You will want to order roof trusses with raised heels (https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/), so you can get full insulation depth from wall-to-wall with blown in fiberglass. Heel height should be R value of insulation divided by three and add two inches so you can achieve adequate airflow above insulation.

Should you want to condition your attic – delete ventilation, raised heels and the Integral Condensation Control. I would apply closed cell spray foam two inches to the underside of roof steel, then add open cell spray foam to desired R value.

For walls – best results will be from two inches of closed cell sprayed to inside of wall steel, then fill balance of wall cavity with either open cell spray foam, or unfaced batts (ideally stone wool https://www.hansenpolebuildings.com/2013/03/roxul-insulation/). You could also use BIBs to fill (https://www.hansenpolebuildings.com/2011/11/bibs/). Do not place a Weather Resistant Barrier (WRB) under wall steel or a vapor barrier on inside of wall.

As an alternative to spray foam, you can use a WRB between framing and wall steel, then BIBs with an interior vapor barrier or faced batt insulation.

Energy costs are not going to go down, so I would encourage you to err towards more insulation rather than less – and (since most heat loss is upward) invest more into added ceiling insulation than walls.

In warmer, humid climates like yours, your HVAC system should include an Energy Recovery Ventilator (ERV) regardless of what your choice of insulation systems ends up being.

Stamped Plans, Bottom Chord Loads, and Spray Foam Options

This Monday the Pole Barn Guru answers reader questions about engineer stamped plans,  hanging sheetrock of OSB from truss bottom chords, and the best choice for spray foam insulation in a post frame building.

DEAR POLE BARN GURU: Are your drawings engineer stamped to meet local municipality requirements? ERIK in LAS VEGAS

Engineer sealed pole barnDEAR ERIK: Yes, our structural plans, sealed by our independent third-party engineers are designed to meet or exceed loading requirements for each individual building’s jurisdiction. We have provided several buildings in Clark County, including the giraffe barn at your Lion Habitat Ranch in Henderson. We do always have our clients verify load conditions with their Building Department prior to ordering. This will give you an idea of what will be on form to be completed: https://www.hansenpolebuildings.com/2020/08/building-department-checklist-part-i/.

 

DEAR POLE BARN GURU: Can I hang 7/16″ osb or 5/8″ sheetrock from my pole barn style garage with 4′ on center trusses with a 2×4 bottom chord & 2×6 top chord & a 28′ span? I have thought of running 2×4’s perpendicular to the trusses but am concerned about all the weight. Any thoughts or ideas for me? DAVID in HELENA

DEAR DAVID: If your building’s roof trusses have been designed for at least a five psf (pounds per square foot) bottom chord load (often shown as BCDL on engineered truss drawings) then they could support weight of either 7/16″ OSB or 5/8″ sheetrock. Neither product is designed to span greater than two feet, so you would have to add framing between trusses to adequately support.

This circumstance is why all Hansen Pole Buildings prefabricated wood roof trusses spanning 40 feet or less are designed with a minimum BCDL of five psf or more – just an added service for our clients who decide to add a ceiling later on.

 

DEAR POLE BARN GURU: I have read many, many of your replies pertaining to the multitude of insulation questions to try and find a scientific and experience answer to an insulation quandary my daughter will experience in a matter of days. I am very familiar with & proficient in stick build & the associated vapor & breathing issues in that form of home building. However, the post & frame discipline is different & yet has some similarities in physics. My daughter & son-in-law are already in contact to have 4″-5″ of “open-cell” spray foam for insulation for walls & roof. I completely understand house wrap, condensation etc….my question is this. Should Tyvek be used between the metal sheathing (siding) & the open- cell or not? The trusses are spaced 2ft o.c. & 2×4 purlins are laid flat 2ft. o.c. then standard girt spacing, etc. on walls. I just want to make sure I provide my daughter with the correct answer so as her family can live in their home with the concern. I thank you for your time and expertise. NICK in MORRIS

DEAR NICK: Luckily physics remains same from stick built to post frame!

For walls – my preference would be two inches of closed cell sprayed directly to wall steel, then fill balance of wall cavity with unfaced insulation of your choice. Fiberglass would be least expensive for this, although open cell spray foam or BIBs are options (I have done BIBs personally and think it is great).

For roof – if attic space is to be conditioned and there is no other provision for condensation control, I would start with two inches of closed cell directly to roof steel and then open cell to it to desired R value. If attic space is to be ventilated and insulation placed at ceiling level, if no condensation control do closed cell again, then blow in insulation at ceiling level. This will require adequate eave and ridge ventilation.

 

Answers for Brian’s Barndominium Builder

Answers for Brian’s Barndominium Builder

Should you have missed yesterday’s episode, please click back to it using link at bottom of this page – it will make more sense as well as being more entertaining!

Hello Brian ~

My Father and his five brothers were all framing contractors, so I was raised in a world of trusses two foot on center and vertical stud walls. Even in my first few years of prefabricated roof trusses (as a truss designer/salesman/manager) – we used to laugh when builders would order trusses for pole barns. 40 years of experience has taught me they were right (post frame builders).

Having personally erected a plethora of buildings, both stick frame and post frame, it is far less time consuming to erect a post frame building with widely spaced trusses (and purlins and ceiling joists) than it is to stud wall frame. With a minor investment into building a set of four ‘winch boxes’ entire sections of roof framing can be assembled on the ground and cranked up into place. Not only is this fast, it is also far safer.

Learn about winch boxes here: https://www.hansenpolebuildings.com/2019/10/winch-boxes-a-post-frame-miracle/

Mindi’s quote does not include OSB sheathing or either 30# felt or ice and water shield to go between OSB and roof steel. These can be added, however there is really no structural reason to do so – it is going to add to both investment and labor. Should you opt to have your roof sheathed, OSB (or plywood) will run from fascia to ridge across purlins 24″ on center, so spans would be no greater than trusses every two feet.

If you do opt for roof sheeting, you might want to consider going to 5/8″ CDX plywood and a standing seam steel. It will be more expensive however it does eliminate any through fasteners.

When you create an encapsulated building (spray foam to all interior surfaces), you do not want to ventilate it, as you would then lose your air seal. With your OSB’s underside sealed by closed cell spray foam and upper side protected with 30# felt or ice and water shield, there is no way for your OSB to become moist. If this is still a concern, an upgrade to plywood could be done.

Certainly one could place scissor trusses every two feet – it would then require adding structural headers (truss carriers) between columns to support them – reducing ‘line of sight’ beneath them. In order to place two foot tall windows in your knee walls above wing roofs, your building height would need to increase to allow for their height. This entails a whole bunch of connections – trusses to headers, headers to trusses and connections are always a weak link of any structural system. It would also mean having to add 2×4 flat on top of either trusses or sheathing in order to have something to screw roof steel panels to (you cannot screw directly to OSB only). Single trusses also require added bracing not required with ganged (two ply) trusses.

You will find drywall installs far better over horizontal framing (wall girts) https://www.hansenpolebuildings.com/2019/09/11-reasons-post-frame-commercial-girted-walls-are-best-for-drywall/. By utilizing bookshelf girts your exterior walls only have to be framed one time – saving materials and labor over stud walls with horizontal nailers. Building Codes also do not allow for studwalls over 12′ tall, requiring added engineering.

We do have sample building plans available on our website for your builder to review and get a feel for https://www.hansenpolebuildings.com/sample-building-plans/. You may also want to invest (in advance) in our Construction Manual (please contact Bonnie@HansenPoleBuildings.com) – you do get one included with your building purchase (plus you have access to an electronic version through your login).

Please keep in mind – not only have I been involved in design, provision and/or construction of roughly 20,000 post frame buildings, I also happen to live in one. As technology brings about better design solutions, we have always been quick to adopt them, as our goal is to provide structurally sound buildings where benefits outweigh investments.

Feel free to have your builder reach out to me directly at any time.

I Think I Have Made Some Errors!

I Think I Have Made Some Errors!

If you are a post frame building kit provider or a builder reading this article – please STOP SELLING ONLY ON A CHEAP PRICE. You are leaving dissatisfied clients in your wake and doing a disservice to our industry.

Reader RICK in IDAHO writes:

“Hello Sir! I think I have made some errors when I had my PB built regarding insulation plans. 30×40 with 12’, 8” side walls on the inside. Cement floor. No Tyvek or other barriers on walls or roof, just steel on wood all around. Soffit vents all the way around and vented roof cap. Was planning to have insulation blown in walls and ceiling, with a vapor barrier (reinforced plastic?) facing interior occupied area. Did not use closure strips but used canned spray foam to insulate/seal the ribs and edges walls, top and bottom and roof. Trusses were engineered for sheet rock ceiling. Won’t have temps above 50 F in winter on occasion But will try to keep above freezing in winter. No AC in summer. South East Idaho- hot summers and some -10/20 degree nights in winter with generally low humidity year around. Edge of the Idaho desert. Any advice? Thanks for sharing your knowledge with us!”

Thank you Rick for your kind words.

I cannot fault you – an average person having a post frame (pole) building built doesn’t know what they don’t know. I see this situation occur over and over when building providers or builders do not thoroughly explain options and their benefits to clients, instead relying upon a cheap price.

If your concrete slab on grade does not have a vapor barrier under it, seal the top of your floor. https://www.hansenpolebuildings.com/2019/02/how-to-properly-apply-post-frame-concrete-sealant/

Use two inches of closed cell spray foam against your wall and roof steel – if not, you run a high risk of condensation troubles. If you are going to blow insulation into your walls, use a product such as BIBs. https://www.hansenpolebuildings.com/2011/11/bibs/
Do not use a vapor barrier inside of either your walls or ceiling. Make sure the spray foam applicator does not spray over your eave or ridge vents.

All of these things are manageable, they just could have been solved far more economically if they had been done right to begin with.

My Pole Barn is Chilly

Reader TIM from INVER GROVE HEIGHTS, MN has a chilling challenge, he writes:

“Fabulous site, congrats.  I have a 40×60 pole barn with 10ft ceiling to the bottom of the rafters.  Last year I put a 150k btu heater in to try and take the chill out a bit.  It didn’t work so well because the building is not tight at all.  I know I could spray foam it.  Is there anything that I could do less expensive?  I was told to put 6mil ply sheeting under the rafters at 10feet to seal that space and the leaks that are on the end of the building away from the space below where the heater is.  Plus I would not be heating the area above anymore.  I only heat it for a few hours 4-5 days a week.  Thoughts?”

Possible solutions could end up making two dollars per square foot of surface (for two inch thickness) of closed cell spray foam a bargain.

If you do not have some form of condensation control between roof framing and roof steel, you are going to need to closed cell spray foam the underside of your roof steel (again two inches), otherwise it will rain inside your building.

As heat rises, let’s begin there. Determine if your roof trusses are designed to support a ceiling load. This can be found by examining your engineered truss drawings supplied when trusses were delivered. If not available, look for the manufacturer’s stamp located on truss bottom chords. If you contact them with your site address, they should be able to pull up your building’s records. You want to find at least a five psf (pounds per square foot) ceiling (bottom chord) dead load (although three psf would support a steel liner panel ceiling). If inadequate to support a ceiling, your truss manufacturer can provide (for a nominal fee) a repair design to upgrade your trusses. Once it is determined trusses can support a load (or have been repaired in order to do so), add ceiling framing between trusses (if over two foot on center) to support drywall (my personal preference – use 5/8″ Type X) or a steel liner.

Blow in R-60 of fiberglass or cellulose insulation on top of your new ceiling. Make sure to not block airflow coming in from sidewall vented soffits. Should you not have a vented overhang and vented ridge cap, you will need to add gable vents located in the top half of each endwall with a minimum of 576 square inches of net free ventilation area in each endwall.

Made spray foam sound easy, didn’t I?

Air Sealing Your Post Frame Barndominium

Unless someone reincarnates Nikola Tesla (and he is sane) chances are good energy costs are not going to decrease. Air sealing your post frame barndominium or shouse increases your comfort by reducing drafts and cycle time your heating and cooling systems are running.

Air sealing your barndominium reduces humidity increasing comfort levels. A drafty barndominium is more than just a waste of natural resources, it also means higher energy bills. Air sealing will automatically lower your energy bills due to less leakage of conditioned air.

Using two inches of closed cell spray foam directly inside steel siding panels not only air seals exterior walls, as it is an effective vapor barrier, but also provides approximately a R-14 level of insulation. Effective applications also require installing form fitted inside closure strips at top and bottom of every wall steel panel – including window and door openings. Closure strips keep spray foam in your walls rather than oozing out and keeps small crawling and flying critters out.

For those who opt not to utilize closed cell spray foam, air sealing begins with a totally sealed Weather Resistant Barrier (WRB) wrapping all framing before steel siding is applied. For further reading on Weather Resistant Barriers please see: https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/

Care should be taken to effectively use WRBs around openings for windows and doors, as well as utilizing caulking and self-adhesive sealant tape for an airtight seal. Place sill gaskets under all exterior doors. Use spray foam or caulk to fill any gaps between doors and windows and adjacent framing.

In Floor Heat System InstallationWhen placing under slab vapor barriers, run up inside of pressure preservative treated splash planks and sealing to top and around columns. Install seal gasket under pressure treated base plate (mud sill) and caulk inside edge to concrete slab.

With wall insulation systems other than closed cell, use a clear visqueen vapor barrier on the inside of all framing. Seal every penetration in this vapor barrier.

Before installing interior window and door trims, caulk where trim will meet frames. Make sure door sweeps are installed and the threshold is properly adjusted.

Common infiltration paths include attic access and simply insulating envelope (or shell) isn’t enough. In fact, insulation’s ability to perform is almost cut in “half” if not air sealed first.

Expandable polyurethane is used in areas too wide for caulk. If an area is wider than 1/4″ caulk can fall out of grooves. Acrylic-latex caulk is for all gaps small enough for caulk to function properly such as base plate and seam between floor and wall and wall and ceiling. Fire-rated caulk is non-combustible and for any areas where wires penetrate through base plates, walls, etc. (This is a recently implemented new national code.)

While it seems obvious gaps and crevices in a barndominium should be sealed, most builders either have not yet begun or just recently started utilizing air sealing processes. If hiring a contractor, make certain complete air sealing processes are spelled out in contractual documents – money you will save over your barndominium’s lifespan.

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.

 

Fishing Cabin Insulation

Fishing Cabin Insulation Blog-Compliments to Rick Carr in sharing this post on how he insulated his fishing cabin. 

My insulation challenges are a little unique due to having an above ground crawl space, radiant floor heating above the sub floor, 2×8 and 2×10 walls and having a partial attic area (over the bedrooms) with the remainder a vaulted ceiling.  My insulation is done and the drywall is going up.  The test for the plan will wait until next winter.

Here is what I did.

First I had closed cell foam sprayed.  In the crawl space, walls 3 inches closed cell spray foam, completely sealed and R 21.  Also we sprayed the underside of the subfloor to 1 ½ to 1 ¾ inches.  The goal was to get R 1- to 12 on the underside of the floor.  The radiant floor people tell me that heat moves to cold, so R 12 under the floor will have heat going up into the living space rather than down into the crawl space.  There is also R 10 foam board and poly under the concrete.

I also had 3 inches of spray foam, R 21, on the underside of the roof steel.  The drywall will go on the underside of the roof purlins.  We used 2 x 10 roof purlins to get a 9.5 inch cavity for insulation.  I put Tyvek under the roof steel, so the spray foam actually adheres to the Tyvek, this will allow replacement of roof sheets, if ever needed.  This still leaves a 6 inch space for R 21 unfaced batt insulation.  Spray foam people will tell you that because the spray foam completely seals the effect is greater than the R value.

The Attic side of the divider wall was also prayed with 3 inches of closed cell foam.  There wasn’t a normal 6 inch cavity to fill with batt insulation which made the spray foam a good choice for this.  We also blew in 16.5 inches of fiberglass insulation into the attic above the bedrooms for R 49 in that area.

 The walls are another matter.  The 42 foot walls on the north and south sides of the building are 2 x 10 walls with 9.5 inch cavity.  The 30 foot east and west walls are 2×8 walls with 7.5 inch cavity.  I chose blown in wall insulation for the walls.  It is commonly thought that you can only have a pro blow insulation into your walls, not so, I did it myself, with some help.

I chose Owen Corning’s Procat product and system, which can be purchased from contractor supply houses. https://www.owenscorning.com/insulation/products/procat  This is the same product as used in the ceiling.  The supply house will loan you the blower, which has a control at the end of the hose.  You staple Insulweb netting to the framing, cut a small slit in the netting, insert the hose and blow it in.  This might be a little more costly than batt insulation, but where do you find batts for 2 x 10 walls?  Also the electric all over the place gets in the way of batts, no problem, filled in and around.  The blown in insulation fills into all cracks and spaces.  What you spend in the product is also made up in time/labor savings; it goes very quickly once you get the hang of it and the netting up.

The puffing or pillowing is not a factor because the product is light enough that the drywall will straighten it.  Also you can use your free hand to minimize the pillowing if you have a large cavity.  The product R value for 5.5 inch cavity walls (2×6) is between R 22 and R 24 depending on how full you pack it in.  With my 2×8 and 2×10 walls, the R value is literally off the chart, well over R 30.

 

I think I’ll be snug this winter.

Insulating an Existing Post Frame Building Attic

We are in an era where climate control of brand new post frame buildings is extremely common. It is also much easier to insulate (or plan for it) at time of construction, rather than having to go back and do it afterwards. 

For new post frame buildings, here is my Ultimate Guide to Post Frame Building Insulation: https://www.hansenpolebuildings.com/2019/11/post-frame-building-insulation/.

Loyal reader DAMON in SPOKANE is fortunate to have some parts of his existing post frame shop made easy for retrofit insulation. He writes:

“Hi,

First I want to say I love your web site, the information I’ve been reading is invaluable! I am located in Spokane County. I have a 24x24x10 post frame garage that was here when I purchased the house. The walls have commercial girts R19 insulation. I would like to heat this garage and use it as a woodworking shop. Right now the ceiling is open and there is no insulation. The roof is sheeted with OSB, then felt then steel roofing panels. There is no ventilation or overhangs to install soffit vents. The roof has 4:12 pitch.

I am considering one of two options. The first is to spray foam under the roof decking with closed cell foam, about 2″ which would give me about an R14. This would mean I would have to heat a larger air volume all the way up to the roof. Is this an effective method? Will the closed cell foam seal everything and hold the warm air in efficiently? I supposed I could install a couple of slow turning ceiling fans to push the warm air back down.

The second alternative is to add a ceiling. I was able to confirm that the garage was built with bottom load trusses. I could install joists and an osb ceiling and then go with a blown in insulation, maybe R38. Because there is no ventilation I was thinking of adding large appropriately sized gable vents to provide the ventilation since I do not have soffit vents nor a ridge vent.

Of the two options, is one a better consideration than the other? I know you’re probably pretty busy, I appreciate any time you have to help me with my decision.”

Mike the Pole Barn Guru responds:
Thank you very much for your kind words, hopefully you have been entertained as well as informed!

As your building was built with trusses designed to support a ceiling, I would recommend you pursue this route. You would need to add gable end vents in the upper half of each gable with a net free ventilation area of at least 139 square inches per end. Please keep in mind this is not vent dimension, but net free area only.

Your building’s roof trusses probably do not have raised “energy heels” so it would be most practical to use closed cell spray foam insulation along two feet closest to each eave sidewall (applied to top side of ceiling finish). I would recommend you blow a minimum of R-49 across the balance of the attic area as this will meet minimum recommended attic insulation levels from www.energystar.gov. Your spray foam applicator can make recommendations for the thickness of his or her product.

Also, please consider using 5/8″ Type X sheetrock for your ceiling. It will be less expensive than OSB and provides some degree of fire resistance.

Ganged Wood Trusses & Closed Cell Spray Foam Post Frame Condensation Control

Ganged Wood Trusses and Closed Cell Spray Foam Post Frame Condensation Control

Ganged wood trusses are most usually two individually fabricated metal connector plated roof trusses, fastened together with either nails or even better Simpson Drive Screws (https://www.hansenpolebuildings.com/2017/03/simpson-drive-screws/), so they work together as a conjoined pair.

True doubled trusses (not two single trusses spaced apart by blocking) afford many structural advantages (https://www.hansenpolebuildings.com/2018/09/true-double-trusses/). However if closed cell spray foam is being used to control condensation underneath steel roofing, a little extra prevention is worth a pound (or two) of cure.

Most often conditioned post frame buildings are designed around having a flat (or slightly sloped using scissor trusses) ceiling. Warm moist air from this conditioned space rises into building’s attic and hopefully has a place to go. Most generally best design solution involves venting this dead attic space. Appropriate amounts of air intake provided by eave soffit vents and air exhaust utilizing a vented ridge will eliminate most moisture.

As those of us who did not nap during science classes are aware – warm air rises. Some of this warm air will get trapped below roof purlins or other attic framing members and not exhaust as imagined.

There are many methods of controlling or eliminating this warm and moist air from coming into contact with cooler roof steel. Least expensive (although potentially labor intensive if windy) would be a reflective radiant barrier (https://www.hansenpolebuildings.com/2017/05/effective-reflective-insulation/). One step up in investment, but very easily installed, would be an Integral Condensation Control (https://www.hansenpolebuildings.com/2017/03/integral-condensation-control/).

Some folks opt to sheath over trusses and roof purlins with OSB (Oriented Strand Board) or plywood, with 30# asphalt impregnated paper (roofing felt) placed between sheathing and roof steel. This can tend to run up one’s investment, as not only will more material and labor be directly involved, but trusses also must be appropriately designed for added weight carrying ability.

Enter closed cell spray foam. Long time readers have grown tired of me solving condensation challenges by people who did participate in one of these solutions and are now faced with a drip-drip-drip. Two inches of closed cell spray foam applied beneath a steel roof between purlins and trusses will create an almost entirely effective thermal break and take care of nearly all condensation issues.

Except…..
Metal connector plates trusses have pressed steel plates on each side. These plates project slightly from lumber faces and when two trusses are joined together, some gaps will occur between them. Gaps wide enough to allow for a significant flow of warm moist air to reach your roof steel, condense and start wreaking havoc.

There is, however, a simple fix, easily done during building framing. Before conjoining two or more trusses, place enough urethane or acoustic caulking between top cords to provide a complete air seal when in service!

Fire Rated Spray Foam Insulation

Spray foam insulation has become increasing popular for achieving high R value building shells. One downside of spray foams has been they are not being fire resistant.

I was pretty excited to read this on a post frame building contractor’s website:

“Installing foam insulation can either be sprayed or foamed-in-place. Foam has the ability to create an air barrier for the smallest of air leakages. Spray foam doesn’t retain water, providing excellent protection from the growth of mold and mildew. While foam insulation is generally more costly than other insulation options, it does have higher R-values and is fire rated.” 

As this particular contractor is a friend of mine, I dropped him back this question, “Spray foam insulation is fire rated?”

To this he replied, “Yes, some are, Tiger makes one.”

News to me, so I fired up my laptop and headed to Google, looking for more information.

Tiger Foam™ insulation (https://tigerfoam.com/sprayfoaminsulation/), according to their website, “is a proven leader in providing spray foam kits, supplies and accessories to homeowners and contractors alike.”

Again, according to their website, “We offer retails sales for small projects and wholesale, bulk pricing for bigger jobs. Our expert customer service team is always available to answer questions and help plan projects. Whether you’re trying to save money on your monthly energy bills or working to satisfy your customers. Tiger Foam can help. Most of all, our products provide high performance and great value. Become a customer today and get you the tools you need to start saving energy dollars!”

Well, sure enough, Tiger Foam™ offers a ‘Fast Rise’ kit providing a Class 1 Fire Rating. This fire rating means this building material is highly resistant to fire and does not spread flames quickly. Building materials with a Class 1 fire rating are often man-made or nonorganic substances. Other Class 1 building materials include brick, tile and cement.

I have never personally installed Tiger Foam™, however I have paid to have closed cell spray foam insulation installed by a professional installer. If you are considering using a closed cell spray foam for your new project, discuss fire rating with your installer of choice.

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.

More Condensation Fun

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.

Reader KRYSTA in SPOKANE writes:

“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!”

Mike the Pole Barn Guru writes:

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.

Unvented Post Frame Attics

Unvented Post Frame Attics

Energy efficiency concerns have literally become a “hot” (pun intended) topic in new construction, and post frame construction methods are no exception to inclusion. Traditionally buildings have had insulation placed or blown into dead attic spaces, directly above a ceiling. Unvented attics have entered fray as an alternative.

 

To construct an unvented attic, air-impermeable insulation (think closed cell spray foam) will be applied in direct contact with steel roofing (or sheathing) underside and gable end walls so as to tie roof insulation into wall insulation below. Moving insulation boundary to the roof deck underside allows temperature and humidity conditions in the attic to be reasonably close to those of the conditioned building interior.  No attic floor vapor retarder or insulation should be installed with an unvented attic assembly.

Closed cell spray foam insulation products meet code requirements for use of an air-impermeable barrier applied to underside of roof. This prevents air infiltration and limits accumulation of airborne moisture in the attic. Using closed cell spray foam insulation applied to underside of roof deck eliminates a need for alternative methods of condensation control such as reflective radiant barriers or CondenStop (https://www.hansenpolebuildings.com/2014/07/condenstop/).

In hurricane or wildfire prone areas wind-driven rain or embers cannot enter an unvented attic assembly, as there are no vents.

Spray Foam

Vented attic designs originated in cold climate areas. In these cold climates, attic ventilation is commonly used to remove warm, humid air from attic spaces. Air leakage from conditioned spaces below a ceiling greatly increased likelihood of moist air entering attics. Without adequate attic ventilation, the underside of the roof deck can have condensation form and interior heat can cause roof surface snowmelt leading to ice damming.

Use of venting to control moisture in cold climate attics comes with some inherent challenges. In high snowfall areas, snow accumulation and drifting can often block ridge vents. This limits venting and increases potential of damage due to ice damming, roof leaks and condensation.

Closed cell spray foam does not come without added upfront investment costs, however some of these can be mitigated in materials and/or labor savings.

Considering climate control of your new post frame building? If so, an unvented attic may be a viable solution worth investigating.

 

Net Zero Post Frame Homes

Net Zero Post Frame Homes

Energy efficiency has become a huge focus in every type of home construction. Post frame homes can be net zero, just as well as stick frame.

Our environmental commitment allows us to design post frame homes to reduce environmental impact. High performance design and advanced engineering make it easier and more attainable to build a home producing as much energy as it needs through renewable energy, known as net-zero energy.

A net-zero home will be more than a house with solar panels. It’s a house designed to put energy conservation first: from framing to finishing. An airtight structural shell paired with additional options – such as highly insulated wall systems, high performance windows, passive solar design and more – mean any Hansen Pole Buildings’ post frame home can be designed to achieve net-zero energy.

Reader IAN from MIDDLETON writes:

“Mike-

First, I want to let you know how much I have enjoyed reading your blog. I started reading through it topically to answer some of my questions, but because I have been finding so much good information, I resolved to start at the beginning and read through chronologically to make sure I don’t miss anything. Thank you for sharing your lessons learned from decades of experience.

I’ve been exploring options for a cost effective and energy efficient single family home. Reading on your blog has convinced me of the advantages of post frame construction, but I have also been reading about ways to achieve high energy efficiency. In particular, I’m interested in ways to incorporate thorough air sealing and extra insulation (in particular for walls) into a post framed structure. I have found numerous references on the internet to the ways that post frame construction is generally moderately more energy efficient that stick framing, but I have only found a few examples that specifically address trying to achieve a very high level of energy efficiency in a post framed house. The clearest example I’ve found is the following short video that profiles the construction of a net zero single family home in upstate New York: https://youtu.be/PKXNwdvUNj4

My questions for you:

Have you designed a post framed home with high energy efficiency in mind? What kinds of strategies did you use to achieve high energy efficiency?

Have you ever designed a super-insulated post framed home, and if so, how did you incorporate the additional insulation? Some approaches used in stick framing are double stud exterior walls, or supplemental rigid foam insulation between the sheathing and siding (likely not ideal for a steel clad post framed building). Have you seen these or other super-insulation strategies used on post framed buildings?

Finally, have you ever had a post framed home blower door tested for airtightness, if so, how did it perform? Do you have any recommendations for air sealing strategies specific to post frame construction?

Thank you for considering my questions; keep up the good work!”

Thank you for your kind words. Sadly, most post frame home clients are just not savvy enough to be willing to make an extra upfront investment to super insulate their buildings.  I have designed several post frame residential buildings for my own use, so I have learned from mistakes. Also, technologies have improved greatly in recent years, making energy efficient designs more practical.

For walls, my current best recommendation would be to use two inches of closed cell spray foam against siding insides. Walls would be framed with bookshelf style girts to create a deep insulation cavity. BIBs insulation would be used to entirely fill the wall cavity. Inside of the  girts, covering columns as well, two inches of rigid closed cell foam board would be applied with glue, and all seams sealed. Gypsum wallboard (sheetrock) would be then glued to the foam board. Using rigid foam board inside eliminates any thermal bridging as well as creating a vapor barrier.

With 2×8 bookshelf girts, a wall system of over R-50 could be obtained using description above.

I am not yet sold about creating a warm attic – so I’d use 22 inch raised heel trusses and blow in 20 inches of fiberglass to go R-60 and beyond.

I haven’t seen any post frame air tightness tests, however even 25 years ago (when I was building post frame buildings) we had instances where our post frame homes and commercial buildings were so tight, a window had to be opened in order to close exterior entry doors!

Good Luck! And let me know how it all turns out. I’d love to see pictures of your progress!

 

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.