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Vapor Barriers, Post Longevity, and Spray Foam

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

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

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

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

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

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

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

This entry was posted in Building Interior, Lumber, Columns, Insulation, Pole Barn Homes, Pole Barn Questions, Pole Barn Design, Roofing Materials, Pole Barn Planning, Barndominium, Ventilation and tagged steel roof moisture barrier, moisture barrier, UC-4B, open cell spray foam insulation, closed cell spray foam insulation, vapor barrier, spray foam, UC-4B pressurem Preservative Treated columns on April 3, 2024 by admin.

Properly Insulating Between Roof Purlins

Properly Insulating Between Roof Purlins

Reader SAM in MATTAWAN writes:

“Hi, I have a wood framed pole barn that is fairly unique in design and doesn’t have any “attic” space. It’s very similar to what a steel building would be. There are 2×8 roof purlins to support OSB sheathing. My question is regarding ceiling/ roof insulation and venting. I will be doing a shingle roof and vinyl siding. Since there is no attic space, are ridge and eave vents still required? And what would be recommended for insulation? Spray foam would probably be ideal, but more than likely out of budget. Would fiberglass batts be ok to use right up against roof OSB? Thanks.”

According to Martin Holladay (Green Building Advisor):

“Experts usually advise builders that you can’t install fiberglass insulation directly against the underside of roof sheathing. If you want to install fiberglass between your rafters, you have two basic choices: either include a ventilation channel between the top of the fiberglass insulation and the underside of the roof sheathing, or install enough rigid foam above the roof sheathing to keep the roof sheathing above the dew point during the winter. These rules were developed to prevent damp roof sheathing.”

With post frame construction ‘purlins’ would replace ‘rafters’ above.

You have some options….

Per IRC R806.5 (4) In Climate Zones 5, 6, 7 and 8, any air-impermeable insulation shall be a Class II vapor retarder, or shall have a Class II vapor retarder coating or covering in direct contact with the underside of the insulation.

IRC R806.5 (5.1.1) Where only air-impermeable insulation is provided, it shall be applied in direct contact with the underside of the structural roof sheathing.

My note – this would be closed cell spray foam

IRC R806.5 (5.1.2) Where air-permeable insulation is installed directly below the structural sheathing, rigid board or sheet insulation shall be installed directly above the structural roof sheathing in accordance with the R-values in Table R806.5 for condensation control.

My note – Van Buren county is in Climate Zone 5A. IRC Table R806.5 requires a minimum of R-20 for your Climate Zone. This would require R-20 rigid insulation boards on top of your roof OSB, you could then use your choice of batt insulations between purlins.

IRC R806.5 (5.1.3) Where both air-impermeable insulation and air-permeable insulation are provided, the air-impermeable insulation shall be applied in direct contact with the underside of the structural roof sheathing in accordance with item 5.1.1 and shall be in accordance with the R-values in Table R806.5 for condensation control. The air-permeable insulation shall be installed directly under the air-permeable insulation.

My note – this would require R-20 (roughly 3 inches) of closed cell spray foam applied directly to the underside of your OSB sheathing, with a balance of insulation (either batts or open cell spray foam) applied directly below between purlins.

In summary – do not vent your eaves and ridge, and fiberglass batts between roof purlins may not be used directly below roof sheathing without either R-20 insulation directly above or below roof deck.

This entry was posted in Insulation, Pole Building How To Guides, Pole Barn Planning, Pole Barn Structure and tagged air-impermeable insulation, rigid insulation boards, insulation, roof purlins, closed cell spray foam insulation, vapor retarder, air- on October 31, 2023 by admin.

Polyiso Pole Barn Ceiling Insulation

Polyiso Pole Barn Ceiling Insulation

Reader MIKE in OXFORD writes:

“I’ve moved into a house that also has an existing 30’x40′ (uninsulated) pole barn. I want to insulate and am considering 2″ thick polyiso foam boards attached to the bottom cord of the roof truss. The roof trusses are 4′ spacing. 1) Do you feel that is a good choice? 2) Do I need to add any type of vapor barrier (or anything else) above the polyiso boards?”

Before addressing your question, some concerns:

Does your building have some method for controlling condensation between roof framing and roof steel? This could be one of several options – well sealed reflective radiant barrier (bubble barrier) or metal building insulation, or solid sheathing (OSB or plywood) with either 30# felt or a synthetic underlayment. If not, two inches of closed cell spray foam should be applied directly to underside of roof steel. You really don’t want it ‘raining’ inside of your pole barn.

What sort of ventilation provisions are made for dead, non-conditioned attic space you are creating? Eave and ridge is best https://www.hansenpolebuildings.com/2018/03/adequate-eave-ridge-ventilation/. While Code requirements can be met with gable vents, they do not provide uniform air flow throughout area being vented.

Are trusses designed to support a ceiling load? Most widely spaced post frame trusses are designed with a minimal ceiling load – generally enough to cover weight of truss and small amounts of wiring and light fixtures. While polyiso is unlikely to create a weight overload, should you opt for other solutions, it could pose a challenge.

Some good things about polyiso insulation – at two inches thick, it only weighs 1/2 pound per square foot. Polyiso insulation delivers a high level of inherent fire resistance when compared to other foam plastic insulation due to its unique structure of strong isocyanurate chemical bonds. Polyiso has an R value of six per inch, however polyiso’s R value gets worse when it’s cold outside. Building Science Corporation’s published research shows polyiso can lose as much as 25% of its R-value when temperature drops (in general R value begins to decrease below 75 degrees Fahrenheit).

Now to address your questions:

1) If you can obtain polyiso at a reasonable price and are looking at only minimal heat retention, it might be a great solution. Personally, I would add a ceiling (steel liner panels are relatively affordable and light weight) and blow in rockwool, provided trusses are adequately designed to support added imposed weight. Adequate ventilation and a condensation control system would be a must for either.

2) A ceiling vapor barrier is only needed if your site has over 8000 heating degree days per year (only found in far northern extremes in our country). Please keep in mind, in order to function well you are not going to be able to have unsealed penetrations for wiring or light fixtures.

This entry was posted in Pole Barn Questions, About The Pole Barn Guru, Pole Barn Planning, Trusses, Ventilation, Insulation and tagged closed cell spray foam insulation, non-conditioned attic space, condensation, gable vents, polyiso, reflective radiant barrier, polisocyanurate on December 29, 2022 by admin.

Advice on Retro Insulating a Minnesota Pole Barn

Advice on Retro Insulating a Minnesota Pole Barn

Reader RYAN in ELK RIVER writes:

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

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

Mike the Pole Barn Guru responds:

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

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

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

This entry was posted in Pole Barn Questions, Pole Barn Planning, Ventilation, Insulation and tagged Ventilation, dead attic space, closed cell spray foam insulation, unfaced batts, eave intake, ridge exhaust, OSB ceiling on December 1, 2022 by admin.

Insulation Options for an Idaho Barndominium

Insulation Options for an Idaho Mountain Post Frame Barndominium

Loyal reader LORISTON in NAMPA writes:

“We are in the initial phase of preparing for our residential post frame home and are excited to partner with Hansen Buildings when ready. Thank you for all the amazing information and supporting your clients. Question: I am targeting a highly efficient design, with >r-40 walls and >r-60 roof. There is a lot that I do not know and humble to learn from others. My mechanical engineering background helps. I would like your advice on a wall and roof design that meets my targeted R-values incorporating (from outside to inside) metal siding, >3/4″ rain screen, rock wool >2″ external insulation, Zip insulated r sheathing for WRB and thermal break/R-value increase, laminated Timber Tech glulam columns with bookshelf / commercial girts, closed cell spray foam internal insulation around 3″ thickness, fill remaining thickness from spray foam to inside edge column with insulation (recommendation would be helpful on type of insulation), internal insulation on inside of wall for thermal break if needed or helps, with final residential area having 5/8″ sheetrock and shop area having metal inside finish. We have not solved how to create a space for utilities on the outside wall as we would prefer to run them on inside of columns or thermal break insulation. We are contemplating internal framed 2×4 walls spaced away from post frame wall to create a space for utilities. No water will be run on external walls, only power, low voltage, gas, telephone as reference. Suggestion on how to run utilities with this highly efficient wall design would be appreciated. Roof is similar to wall, just horizontal with >r-60 performance, as we are targeting a conditioned attic space. Roof exception may be a second zip sheathing layer over the insulation (under rain screen/standing seam metal) but to be determined. Climate Zone 6 region in the Idaho mountains for reference. Post frame columns and wall will be on a full foundation wall with thickness based on wall design. Performance is priority over cost, targeting an air tight and efficient living space. Your experience and practical approach are greatly appreciated. Best regards and thank you.”

Mike the Pole Barn Guru writes:

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

Rather than add an expensive and structurally unnecessary concrete foundation wall, I would recommend embedded properly pressure preservative treated wall columns (as my first choice), columns above grade set into wet set brackets on concrete piers as my second. Either of these can be insulated using R-10 EPS (Extruded Polystyrene) insulation boards. I would run them on the inside of the splash plank, with the top even with the top of the slab, extending down two feet, then outward horizontally two feet.

In Climate Zone 6, I normally would not look towards spray foam as my go to choice, however conditioning your attic and your desire for air tightness come into play, so here goes:

Walls (out-to-in): Steel siding over 2×8 bookshelf girts; 4″ of closed cell spray foam applied directly to inside of wall steel and balance of cavity with either open cell spray foam or rock wool (rock wool being my preference). No internal vapor barrier or continuous interior insulation boards as we want walls to dry to interior, without trapping moisture in the wall cavity.

Roof (out-to-in): Standing seam steel over 30# felt or synthetic ice & water shield (second preferred) over 5/8″ CDX plywood. Zip sheeting is OSB and screws just do not hold well into OSB. We can specify 2×12 roof purlins in order to get a deep cavity for insulation. Closed cell spray foam 5-3/4″ (R-40) plus R23 rock wool (5-1/2″).

This combination will require mechanical removal of humidity.

My normal recommendations would be:

Walls (out-to-in): Steel siding over a Weather Resistant Barrier, over 2×8 bookshelf girts. Fill the cavity with two layers of R15 rock wool. Add R-10 EPS well-sealed on interior. This wall will now dry to the outside.

Roof (out-to-in): Through screwed steel with an Integral Condensation Control factory applied, or standing seam steel over 30# felt or synthetic ice & water shield (second preferred) over 5/8″ CDX plywood. Roof trusses with 22″ raised heels, vent eave and ridge. Blow in R-60 on top of ceiling. This eliminates the expense of heating/cooling a dead attic space.

In either instance, I would have no fears or concerns about running non-plumbing utilities within your wall insulation cavity.

This entry was posted in Ventilation, Footings, Insulation, Pole Barn Questions, Roofing Materials, Barndominium, Pole Building How To Guides, Pole Barn Planning, Shouse, Steel Roofing & Siding and tagged pressure preservative treated columns, closed cell spray foam insulation, concrete piers, rock wool insulation, wet set brackets, extruded polystyrene, spray foam, R-10 EPS, bookshelf girts on September 22, 2022 by admin.

Can I Turn an Existing Pole Barn into a Barndominium

Can I Turn an Existing Pole Barn into a Barndominium?

Reader MICHELLE in GALLATIN writes:

“Hi Mike, my name is Michelle and I live in Nashville Tennessee. I am under contract on an existing pole barn (30′ x 60′) that I am going to turn into a Barndominium. (Picture attached) Today we had the structural engineer come out because the city tells me I will need a letter from him saying the building is up to codes before they will issue a building permit. The structural engineer is not familiar with Barndominiums and has some questions about the roof sleepers. Everything else checks out OK. Is there any possibility he could call you to pick your brain on this? I am willing to pay you for your time on the phone call. Just so you know I am looking to do the spray foam on the ceiling and walls as per all the discussions I read on the barndominium Facebook page. Please feel free to call me if you’d rather talk this through more on the phone with me before the structural engineer calls you. If you decide you have the time to take his call.”

Mike the Pole Barn Guru says: Because Michelle is so nice, here are my insights, addressed by photo:

Wood entry door in wood jambs should be replaced with an insulated, factory painted, steel door with factory painted steel jambs

Reflective Radiant Barriers (RRB) are only effective at controlling condensation when seams are thoroughly taped together.

Roof trusses are unlikely to have been designed to support a ceiling load – requiring further analysis. Provided they are either adequate, or can be repaired to carry a ceiling load, heels are not deep enough to provide full depth of insulation from wall-to-wall. Design solutions could include (a) remove reflective radiant barrier from roof and use closed cell spray foam insulation to underside of roof deck, or (b) use closed cell spray foam closest to eaves on top of ceiling with blown fiberglass to R-60 in balance of attic area. Spray foam needs to be installed to allow for at least one inch of clear airflow above. Diagonal braces at corners are inadequate to properly transfer shear loads. It is possible to replace screws at top and bottom of each roof and wall panel with 1-1/2″ #12 diaphragm screws, with one each side of every high rib. This should get you to 80-90 pounds per lineal foot of shear resistance.

Eave lights should be removed as they will not transfer shear loads and will be covered with insulation and interior finish materials. Truss carriers (and their connections) should be checked for adequacy to carry concentrated loads from intermediate trusses. As a carrier is on the inside face of columns, an interior set of wall girts will need to be added to support finishes.

Sliding doors will need to be replaced either with solid walls, or an appropriate door or window(s). I would want to see an X brace between the end truss and the next truss at centerline connected to each chord with a Simpson LSTA12 or similar.

Connections between roof purlins and trusses are probably inadequate, particularly at endwalls.

Truss bottom chords should be braced laterally no less than 10′ on center (and probably more like every 6-7′). Ceiling joists would fulfill this requirement.

Remove any current concrete slabs – re-pour four inches thick over no less than four inches of compacted gravel, a 6mil minimum well-sealed vapor barrier and ideally R-10 EPS insulation boards.

If a dead attic space will be created, provide venting at eaves and ridge

Roof steel is showing signs of aging, I would recommend replacing – remove RRB and order roof steel with an Integral Condensation Control factory applied, unless roof assembly is to be insulated only with spray foam insulation.

Perimeter of slab should be insulated with R-10 EPS boards down two feet, then outwards two feet

My recommendation – I would continue to use this building strictly as a barn and erect a new, fully engineered and Code conforming post frame home elsewhere on this property. Bringing this building up to meet Code requirements as a dwelling will cost more in time and labor than building is worth. https://hansenpolebuildings.com/2022/01/why-your-new-barndominium-should-be-post-frame/

This entry was posted in Budget, Insulation, Pole Barn Questions, Pole Barn Design, Roofing Materials, Pole Barn Planning, Post Frame Home, Pole Barn Structure, Barndominium, Ventilation and tagged Simpson LSTA 12, barndominium, eave lights, blown in fiberglass insulation, truss carriers, closed cell spray foam insulation, insulation, ceiling load, fiberglass, shear loads, structural engineer, Reflective Radiant Barriers on August 23, 2022 by admin.

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.

This entry was posted in Pole Building How To Guides, Pole Barn Structure, Steel Roofing & Siding, Ventilation, Insulation, Pole Barn Questions and tagged self-expanding closures, condensation, ridge closure strips, closure strips, EmSeal, closed cell spray foam, closed cell spray foam insulation on August 18, 2022 by admin.

Tube Framed Metal Buildings

Tube Framed Metal Buildings

Tube framed metal buildings are framed with hollow metal tubes. Most tubes are square, but round and rectangular are also options. They typically have steel siding mounted horizontally as they do not have wall girts to allow for vertical siding installations.

Tube framed metal buildings do have some advantages. They are very inexpensive. They are very lightweight, so typically require minimal foundations. DIY friendly, as they are easily assembled. Uprights are most often every four feet, allowing for direct attachment of interior finish materials capable of spanning this distance.

High winds and/or snow loads can damage light-weight tube framing (you can read about a snow collapse here: https://www.hansenpolebuildings.com/2014/08/versatube/). They are generally available only with fairly low eave heights and four foot bays needed to resist wind loads limit width of sidewall door and window openings.

They come with no provision for condensation control, so require adding products like two inches of closed cell spray foam insulation to prevent condensation. With very narrow wall cavities, it is difficult to obtain more than minimal R values. Being all metal, they are high in thermal conductivity.

Air infiltration can be problematic due to horizontal laps (steel siding is designed to be run vertically), unless every lap is caulked or has strip mastic tape applied. Corner trims are designed to land in flat areas of vertically placed steel panels. Expanding foam closure strips should be placed underneath corner trim flanges to seal spaces between siding high ribs.

This industry (tube framed metal buildings) is plagued with bad reviews, with installation being the source of most complaints. In most instances, the sales process begins with a customer choosing their wants from a menu of options. Once a price is agreed upon a ten percent deposit is made (this happens to be salesperson’s commission). At this point the buyer is now at the building company’s scheduling mercy and more often than not, it doesn’t go well.

I know some people have purchased tube framed metal buildings to use as barndominiums. While this may “work” if located in areas where building permits are not required, or structural plan reviews are not done – in most jurisdictions these are not considered to be permanent structures. Possibilities abound for challenges in obtaining financing, as well as for resale.

Considering a barndominium? Please read this first https://hansenpolebuildings.com/2022/01/why-your-new-barndominium-should-be-post-frame/.

This entry was posted in Ventilation, Barndominium, Insulation, Pole Barn Design, Pole Building Comparisons, Constructing a Pole Building, Pole Barn Planning, Pole Barn Structure and tagged condensation control, expanding closures, closed cell spray foam insulation, tube framed metal buildings, tube framed, thermal conductivity, mastic tape on August 16, 2022 by admin.

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.

This entry was posted in Building Overhangs, Roofing Materials, Pole Building How To Guides, Pole Barn Planning, Footings, Insulation, Pole Barn Questions and tagged Expanded Polystyrene, International Energy Conservation Code, R-10 rigid insulation, rigid board EPS, fascia L trim, splash plank, closed cell spray foam, UC-4A, plasti-skirt, closed cell spray foam insulation on May 12, 2022 by admin.

My Barndominium Attic Has Moisture Issues!

My Barndominium Attic Has Moisture Issues!

Reader DAVID in CHICAGO writes:

“Greetings – I’ve got a pole barn style home that’s about 2.5 years old and I’m having moisture issues in the attic. Hoping I can talk with someone to get a consult or second opinion to resolve as quickly as possible. Let me know if it is something you can connect on. Attached is an image from the attic where you can see moisture on the underside of the metal roof. It freezes at night and then during the day when the sun is out, it melts and drips into the attic insulation.

Attic space is dead, image below. Vented through passive soffit vents and ridge vent, with a few solar blaster ridge vents to help with active venting when the sun is out. Attic insulation is R50 blown in at 20 inches deep. Image of exterior attached. It’s sheet metal that’s then spray foamed on the inside and additional R25 batts. Image below from when we had this same issue earlier this year in February 2021 when the drywall walls and ceilings had to be torn out due to water damage. We purchase in January 2021 and the home is now 2.5-3 years old. There is a solid concrete slab that has in-floor heat. I believe it has a vapor barrier underneath from an image I saw. “

Mike the Pole Barn Guru writes:
You are victim of what is such a simple and economical solution, when planned for in advance. Why builders and building providers fail to address steel roof condensation initially drives me to consider alcoholism!

I do realize they are just ‘selling on a cheap price’, rather than providing a best solution for their client.

Easiest solve is to have two inches of closed cell spray foam applied to underside of roof purlins. Any other solutions will take removal of roof steel panels, adding a thermal break, and then reinstalling roofing.

At time of construction I would have recommended roof steel with an Integral Condensation Control (ICC) factory applied. Investment then would have been a fraction of having to solve it now.

For extended reading on ICCs https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/.

This entry was posted in Pole Barn Homes, Insulation, Post Frame Home, Pole Barn Questions, Pole Barn Planning, Barndominium, Shouse, Ventilation and tagged ridge vent, barndominium, integral condensation control, closed cell spray foam insulation, condensation, metal roof, R50 attic insulation, metal roof condensation on January 6, 2022 by admin.

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.

This entry was posted in Constructing a Pole Building, Barndominium, Pole Barn Planning, Shouse, Ventilation, Pole Barn Homes, Post Frame Home, Insulation and tagged closed cell spray foam insulation, insulation, air movement, condensation, barndominium, rodents, closed cell spray foam on December 2, 2021 by admin.

At What Temperature Can You Not Spray Foam Insulation?

Reader DON in ELLSWIRTH asked this question.

Mike the Pole Barn Guru responds:
Ideally, spray foam insulation should be installed during warmer months. Once temperatures start dipping, spray foam insulation installation processes become a lot more challenging. For a successful spray foam insulation installation, application side surface typically needs to fall between 60 and 80 degrees Fahrenheit. If temperatures are below this range, there’s a greater potential for equipment breakdowns and a larger chance foam will pop, shrink, and fail to adhere properly to substrates.

With this said, it is possible to successfully install spray foam insulation when temperatures dip below this range.

Installing spray foam during winter months is more challenging, but one can increase potential for a successful installation in several ways. One way to successfully apply spray foam insulation in winter, despite less than ideal conditions, is to use a winter blend of spray foam. Closed-cell spray foams can be formulated into a winter blend allowing them to withstand colder environmental and surface temperatures. If you want to install open-cell spray foam insulation, however, it’s not possible to create a winterized formulation. Instead, you must create a suitable environment at installation site (e.g. add heat to building).

In addition to using a right blend of spray foam, making application adjustments for lower ambient temperature is also important. When applying spray foam when temperatures are colder, it’s important to keep hose off any ice, snow, or concrete, as doing so will cause heat to be drawn out more quickly. Minimizing distances between spray rig and application site will also reduce heat loss by reducing hose amount exposed to elements.

On especially cold days, using a smaller application gun mix chamber can keep material warmer. Doing so will slow material’s flow so it stays in heated system longer. It’s important to note installation process of spray foam is generally much longer during winter due to need for such accommodations.

Installing spray foam insulation is a complicated and potentially dangerous process if you don’t have necessary equipment and expertise. As such, it’s always best to hire a professional spray foam insulation contractor—especially during winter, when installation processes are even more complex.

This entry was posted in Insulation, Pole Barn Questions, Pole Barn Planning, Building Interior and tagged insulation, insulation installation, open cell spray foam insulation, closed cell spray foam insulation, winter blend spray foam insulation on October 6, 2021 by admin.

How to Insulate a Post Frame Shop

How to Insulate a Post Frame Shop When No Advance Considerations Were Made

I encourage clients to give some serious advance consideration when erecting new post frame (pole) buildings to any eventuality of future climate control and a need for insulation.

Reader MAC in MILLVILLE writes:

“40 x 30 want to insulate. It will be used as a storage/workshop. I included pictures so you can see what I have. What’s the best way to insulate? I plan on doing metal ceiling liner and most likely plywood on the walls. There is no vapor barrier under the concrete either. I do have a vented ridge and soffit. I hope I provided enough information to be able to answer my question.”

Start by sealing your concrete floor – as this is going to be a moisture source you do not want inside of your new building.

Roof/ceiling – no provision has been made to prevent condensation from happening beneath your roof steel. Sadly I see this occur far too often, as builders, kit providers and local lumberyards just lack knowledge needed to be able to educate and make best recommendations to their clients. You could either (a) remove roof steel, add a method of condensation control (such as a Reflective Radiant Barrier or sheathing such as OSB or plywood with either 30# felt or a synthetic ice and water shield) and reinstall steel using new, large diameter screws. This is highly labor intensive and your roof may not have been designed to support the weight of adding sheathing.

Best solution will be to have two inches of closed cell spray foam applied to the underside of roof steel at roughly two dollars a square foot. Not an inexpensive solution when its need could have been prevented with better advice up front.

Cumberland County is in Climate Zone 4A, as such you should have a minimum of R-49 ceilings and R-20 walls. Perimeter of your slab should be insulated two feet deep with R-10.

I would dig a trench two feet deep around your building, up tight to its pressure preservative treated splash plank and install R-10 rigid board XPS insulation from the height of the top of the slab down two feet. Install a metal, cement board, or cellular PVC panel to conceal any insulation portion left exposed above grade. If cement board is used, it should be a type not reinforced with wood fibers. Install a metal cap as an insect guard to conceal the top horizontal edge of both insulation board and closure panel. Seal cap to splash plank with mastic.

Once you have a ceiling liner in place, blow in R-49 or greater thickness of fiberglass insulation.

For walls, I normally like to see a Weather Resistant Barrier (like Tyvek) between framing and siding. As you do not have this, I would use R-21 unfaced Rockwool stone wool insulation, as it is not affected by moisture. Place a well-sealed 6mil clear plastic vapor barrier over the inside of insulation prior to placing plywood on walls.

This entry was posted in Concrete, Workshop Buildings, Insulation, Pole Barn Questions, Roofing Materials, Pole Building How To Guides, Pole Barn Planning and tagged insulation, cellular PVC panel, condensation, sealing concrete floor, closed cell spray foam insulation, rock wool insulation, concrete floor seal, metal ceiling liner, rigid board XPS insulation, cement board on September 15, 2021 by admin.

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.

This entry was posted in Insulation, Pole Barn Questions, Constructing a Pole Building, Pole Building How To Guides, Ventilation and tagged closed cell spray foam, closed cell spray foam insulation, canned spray foam, sheet rock ceiling, eave vents, vapor barrier, BIBS insulation, ridge vents on November 13, 2020 by admin.

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?

This entry was posted in Insulation, Pole Barn Questions, Pole Building How To Guides, Trusses, Ventilation, Workshop Buildings and tagged truss bottom chords, sidewall soffits, R-60 fiberglass insulation, gable vents, closed cell spray foam, closed cell spray foam insulation on October 30, 2020 by admin.

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 Installation When 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.

This entry was posted in Post Frame Home, Insulation, Barndominium, Pole Barn Design, Shouse, Pole Building How To Guides, Pole Barn Planning, Steel Roofing & Siding, Pole Barn Homes and tagged self-adhesive sealant tape, sill gaskets, closed cell spray foam, closed cell spray foam insulation, f, WRB, vapor barrier, inside closure strips, air sealing, R-14 insulation, weather resistant barrier on October 27, 2020 by admin.

Installing Steel Liner Panels in an Existing Pole Barn

Reader JASON in WHITEHOUSE STATION writes:

“ Hello! I have a post frame 30X40 Pole Barn that was built prior to me owning the house. Currently, the shop is not insulated. I would really like to insulate it, as it’s quite unbearable in the summer and winter. The building has soffit vents, a ridge vent, and two gable vents. With the way the building is set up with all that ventilation (possibly too much?), is putting in a ceiling with insulation on top my best bet? I know there are many options when it comes to insulation, but I am trying to determine what is best for my application. I am leaning towards 6 mil poly on the bottom side of the truss, ceiling liner panel over that with blown in insulation on top. My truss is 8′ on center. Is there a recommended length of panel I should use? Thank you for your help with this. I’m sorry if I asked too many questions.”

Mike the Pole Barn Guru responds:

Provided your building has roof trusses designed to adequately support a ceiling load, your best bet will be to blow in insulation above a flat level ceiling. If you do not have original truss drawings available to determine if they have a bottom chord dead load (BCDL) of three or more, then you will need to find the manufacturer’s stamp placed on truss bottom chords and contact them with your site address. With this information they should be able to pull up records and give you a yes or no. If you are yet unable to make this determination, a Registered Professional Engineer should be retained to evaluate your trusses and advise as to if they are appropriate to carry a ceiling and if not, what upgrades will be required.

If your building does not have some sort of thermal break between roof framing and roof steel (a radiant reflective barrier, sheathing, etc.) you should have two inches of closed cell spray foam applied to the underside of roof steel, or else you will have condensation issues (even with the ventilation). With trusses every eight feet (again provided trusses can carry ceiling weight), I would add ceiling joists between truss bottom chords every four feet and run 30 foot long (verify from actual field measurements) steel panels from wall to wall.

You do not have too much ventilation – and be careful not to block off airflow at eaves. You can omit poly between liner panels and ceiling framing.

This entry was posted in Pole Barn Questions, Pole Building How To Guides, Pole Barn Planning, Ventilation, Building Interior, Professional Engineer and tagged radiant reflective barrier, soffit vents, closed cell spray foam insulation, gable vents, ridge vent, thermal break, Registered Professional Engineer on September 2, 2020 by admin.

Imagining a Retirement Barndominium

Let us face it – I am among those greying in America. According to United States demographic statistics 14.7% of us (over 41 million) have reached a 62 year-old milestone!

What are we looking forward to in our probably final home of our own? We want to be able to spend our time enjoying life, rather than being slaves to home upkeep.

Loyal reader RUSS in PIPERSVILLE writes:

“We are currently in the “imagining” phase of our retirement home. We hope to be building in Maryland very close to the Chesapeake Bay.

We are trying to plan it as an aging in place home. The building will have the top of floor at 4ft. so as to accommodate the recorded last worst flood tide of 11 feet on the bay. Building dimensions are approx. 30 x 60 with a 9ft interior ceiling height. Do you favor engineered floor joists over dimensional lumber and why?

Planning to use Roxul insulation in the walls for R-30. A 2×8 bookshelf girt is 7.25 in. the same as the insulation batts. Can the insulation be place directly
against steel siding if we choose that system?

Also pretty sure that we will be specifying raised heel trusses for the roof. Can the steel siding accommodate the shear requirements for the trusses and an upgrade of wind load specs, or would something like tall wall or storm side sheathing become more practical?

I am convinced that you folks are the only company that we will trust with the design and supply of our home. Your blog and learning posts have been an incredible help in this process. Without the information that you folks publish we probably would have made a serious mistake in looking elsewhere for this.”

Mike the Pole Barn Guru says:
Thank you very much Russ for your kind words, they are appreciated.

My thoughts:

I would consider setting underside of my floor framing to be above the highest recorded flood tide and probably give it an extra six inches. As the floor is being elevated, might as well make sure it is never going to be an issue.

I’d look at 10′ ceilings, as well as 9′. You are going to be designing for energy efficiency so heating/cooling differences should be minimal and those 10 foot ceilings are sure nice. Makes everything feel so much more spacious.

About Hansen Buildings My preference is engineered prefabricated wood floor trusses. To me, I joists always feel spongy. Dimensional lumber varies greatly in both height dimension as well as stiffness of each piece leading to a feeling of lots of ups and downs as you walk across a floor. Both of the last two make running duct work and plumbing within floor cavity near impossible – leaving things having to hang below the floor’s finished underside.

You can place Roxul directly against wall steel inside, however I would use a Weather Resistant Barrier if going this direction. Me personally, I would flash spray two inches of closed cell foam to wall steel inside and then use 5-1/2 inch batts. Closed cell spray foam completely seals your walls and adds rigidity. You would end up with roughly R-37 walls.

Because your trusses are connected directly to sidewall columns, raised truss heels do not create a greater shear load for sidewall steel.

Try to plan your interior spaces to best fit your needs, rather than to try to fit your needs inside into a preconceived exterior box, a difference of a few cents per square foot is not worth the sacrifice of a needed space. Maximize southern windows and minimize or eliminate north facing ones. Plan southern roof overhangs to shield windows from summer sun.

I appreciate your well thought out questions and looking forward to being with you on your continued journey.

This entry was posted in Pole Barn Planning, Trusses, Building Interior, Pole Barn Homes, Pole Barn Questions, Barndominium, About The Pole Barn Guru, Building Overhangs and tagged wood floor trusses, batt insulation, energy efficiency, I joists, closed cell spray foam insulation, Roxul on June 2, 2020 by admin.

How Tall Should My Eave Height Be for Two Stories?

I have learned a couple of things in 40 years of post frame building construction. One amongst these is – most people are dimensionally challenged (no offense intended).

As much as some folks would like to believe, you cannot legitimately put two full height finished floors in a 16 foot eave height post frame building.

Now fear is a strong motivating force. Perhaps it is fear of a building “appearing” too tall or of OMG it will be too expensive keeping people from considering what it actually takes to create a Building Code conforming two story building.

Back in my early roof truss selling days, I had two clients who had relocated from New York state to North Idaho and were building new homes on adjacent properties. Both of them (and their spouses) were relatively short of stature and had decided to build their homes to Code minimum ceiling heights of seven feet. Their reasoning was it would be less space to heat and cool and they could chop two studs out of 14 foot long materials.

Missed in all of this was how much sheetrock waste would be created!

Sidebar – modern Building Codes allow seven foot ceilings under International Residential Code (IRC), however IBC (International Building Code) requires six more inches.

Now I am vertically challenged at 6’5” and would feel very uncomfortable with seven foot ceilings. In my own personal shouse, most ceilings on both floors are 16 feet high!

In today’s exciting episode we will learn together how tall eave heights should actually be to give reasonable ceilings in post frame buildings.

Setting a “zero point” at exterior grade (and assuming slab on grade for lower floor), top of slab will be at +3.5 inches.

To create eight foot finished ceilings requires 8’ 1-1/8” (allows for 5/8” sheetrock on ceilings).

In order to be able to run utilities (e.g. plumbing and ductwork) through second floor supports, I highly recommend prefabricated wood floor trusses (https://www.hansenpolebuildings.com/2020/01/floor-trusses-for-barndominiums/). Generally truss height will be about an inch for every foot of clearspan with a 12 inch minimum.

In my own shouse, we have a 48 foot clearspan floor over our basketball court. And yes, those trusses are four feet deep!

Allow ¾ inch for OSB floor sheeting.

6-1/16″ for heel height of trusses with 2×6 top chord at 4/12 slope (provided you are using closed cell spray foam insulation between purlins)

If using blown-in insulation truss heel height should be R value of insulation divided by 3 plus 2″ to allow plenty of eave to ridge air flow above insulation.

At a bare minimum an eave height of 18’ 0-9/16” will be needed to create those eight foot ceilings.

This entry was posted in Uncategorized and tagged eave height, floor trusses, slab on grade, closed cell spray foam insulation, blown in insulation, OSB floor sheeting on May 20, 2020 by admin.

Whole House Barndominium Fans

Whole House Barndominium Fans

Apparently when it comes to barndominiums, there is a limitless number of subjects to cover!

Reader CAROLYN in CLEVELAND writes:

“We would like to build a post frame home but I would like to have a whole house fan to cut down on cooling costs. Most barndos we see under construction use spray foam insulation directly against the metal roofing/ siding which would prevent the use of a whole house fan. You talk about blown in insulation and roof venting which sounds similar to stick built homes. So is it safe to assume that your designs would allow us to install a whole house fan in the attic space with adequate venting? I fondly recall the ancient airplane engine attic fans 3 or 4 ft wide from years ago and was pleasantly surprised to see the new ones drastically reduced in size and volume. What is your opinion on this?”

Mike the Pole Barn Guru responds:

Most Hansen Pole Buildings’ post frame barndominiums are designed with dead attic spaces – blown in insulation above a sheetrocked ceiling (yes, very similar to stick built homes). This would certainly allow for use of a whole house fan and could prove to be very effective. I would still encourage use of a flash coat of closed cell spray foam insulation inside your barndominium’s wall steel. (For extended reading on flash and batt: https://www.hansenpolebuildings.com/2020/01/flash-and-batt-insulating-barndominium-walls/).

In most climates whole house cooling using a whole house fan can substitute for an air conditioner. Combined with ceiling fans and other circulating fans, whole house fans provide acceptable summer comfort for many families, even in hot weather. In addition to whole house fans, central heating and cooling system ducts can be modified to provide whole house cooling.

A whole house fan pulls air in from open windows and exhausts it through the attic and roof. It provides good attic ventilation in addition to whole house cooling. Whole house fans should provide houses with 3 to 6 air changes per hour (varies with climate, floor plan, etc.—check with a professional to determine what is appropriate for your home). Air-change rate you will choose depends on your climate and how much you will depend on your whole house fan for cooling.

Installing a whole house fan can be tricky and should be done by a professional. An experienced professional should take your attic measurements and install your dedicated circuit wiring and, if needed, your new attic vents.

Attic ventilation will usually need to be increased to exhaust fan’s air outdoors. You’ll need two to four times the normal area of attic vents, or about one square foot of net free area for every 750 cubic feet per minute of fan capacity. Code requirements for dead attic space venting are 1/300th of the attic “footprint” with at least half of this located in the upper half of the attic. Net free area of a vent takes into account resistance offered by its louvers and insect screens. More vent area is better for optimal whole house fan performance.

If your fan doesn’t come with a tight-sealing winter cover, you should either buy one or build one. If you switch between air conditioning and cooling with a whole house fan as summer weather changes, build a tightly sealed, hinged door for fan opening easy to open and close when switching cooling methods.

Be cautious when operating these large exhaust fans. Open windows throughout the barndominium to prevent a powerful and concentrated suction in one location. If enough ventilation isn’t provided, these fans can cause a backdraft in your furnace, water heater or gas-fired dryer, pulling combustion products such as carbon monoxide into your living space.

Whole house fans can be noisy, especially if improperly installed. In general, a large-capacity fan running at low speed makes less noise than a small fan operating at high speed. All whole house fans should be installed with rubber or felt gaskets to dampen noise. You can set a multi-speed fan to a lower speed when noise is a problem.

You may be able to use heating and air conditioning ducts in your barndominium as a means of whole house ventilation. This would involve installing an intake duct to pull air into an attic-mounted system directing air into your heating and cooling ducts. A damper would control exhaust air from your home into the attic. Check with a local HVAC professional to find out if this option is right for you.

This entry was posted in Ventilation, Building Interior, Budget, Barndominium, Shouse, Pole Barn Questions, Pole Barn Planning and tagged air conditioning, whole house fan, barndominium, dead attic spaces, closed cell spray foam insulation, flash and batt system, ceiling fans on May 12, 2020 by admin.

Beginning a Shouse Journey in Washington State Part II

For many readers, you might be considering your new barndominium to be constructed in a jurisdiction without state energy requirements such as those in Washington State. Granted, Washington is a state either on the forefront, or totally out of control, when it comes to mandated energy efficiency, however fuels are not going to get any less expensive, so it is likely you should follow along to design a system combining practicality with efficiency.

Here is my response to yesterday’s writer, Robert:

Thank you very much for your kind words and for being a loyal reader.

Washington Energy Code would be adding to your expense if you were not planning on at least some sort of climate control in your shop area. You can review the current Washington State Energy Code at: www.seattle.gov/documents/Departments/SCI/Codes/SeattleEnergyCode/2015WaStateResidentialEnergyCode.pdf .

About Hansen Buildings With only 1200 square feet of living space, you should be able to easily exceed the state mandated required number of energy efficiency credits. We are currently changing our standard windows to U-29, meeting Washington’s standards. Lesser U values are available, however added expense may well not ever be recouped by energy savings. I would recommend two inches of closed cell spray foam on your walls, then BIBs or similar to fill the balance of wall cavity. R-49 attic insulation is mandated by Code, however your added investment to go to R-60 would be minimal. With either we would recommend raised heel trusses.

ERV systems appear to be a good investment. With a 90% or greater effective rate you could see an improvement of up to five factors in energy loss.

Your shop area will be classified as S-2 given it is over 1000 square feet. This will require a one-hour fire separation between living area and shop (two layers of 5/8″ Type X drywall will accomplish this). Only savings on insurance I can see by two individual structures would be in valuation of your contents, most typically 70% of your home value. You might reach out to your Insurance agent to further discuss your situation.

Radiant in floor heat is wonderful. You can create individual zones to allow you to heat areas individually. https://www.hansenpolebuildings.com/2018/06/geothermal-heating-cooling/

On drainage plans, I would recommend you contact whomever did existing ones for this site. Chances are little modification would need to be done.

Caleb (a very savvy Hansen Buildings Building Designer) will be reaching out to you to discuss pricing of your building shell or shells. We also have available a service to create custom floor plans based upon your individual needs. In this article are links to determine various rooms and sizes as well as a final link, to get floor plans for you. https://www.hansenpolebuildings.com/2019/10/show-me-your-barndominium-plans-please/ .

While “turn key” does exist, you can look at a savings of roughly 25% just to act as your own General Contractor.

I will look forward to accompanying you on your journey!

This entry was posted in Post Frame Home, Barndominium, Insulation, Shouse, Pole Barn Questions, Pole Barn Design, Pole Barn Planning, Building Drainage, Pole Barn Homes and tagged raised heel trusses, closed cell spray foam insulation, windows U-29 energy value, energy efficiency credits, R-49 attic insulation, BIBS insulation on March 12, 2020 by admin.

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!

This entry was posted in Pole Barn Planning, Pole Barn Structure, Barndominium, Ventilation, Building Interior, Pole Barn Homes, Insulation, Post Frame Home, Roofing Materials and tagged closed cell spray foam insulation, reflective insulation, plywood, condensation, roofing felt, reflective radiant barrier, ganged wood trusses, closed cell spray foam on January 21, 2020 by admin.

Tstud for Post Frame Bookshelf Wall Girts

Tstud™ for Post Frame Bookshelf Wall Girts

I have been somewhat enamored of Tstuds’ potential since one of our clients asked if they would be a viable option last summer.

First I had to find out what a Tstud even was, as I had never heard of them before. Once you skip past ads at the start of this video, it gives a pretty good idea of how Tstuds work in traditional stick frame construction: https://www.youtube.com/watch?t=140s&v=mxDSulcLpAE.

Framing with Tstuds minimizes air infiltration, reduces carbon footprints and saves on electrical energy costs.

A lumber frame is obviously great for providing post frame buildings’ structural integrity. However, this same framing is also a massive weak spot in a wall insulation system – where external air can easily infiltrate. Traditionally a Weather Resistant Barrier (https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/) is used to cover a post frame home, shouse (shop/house) or barndominium and blanket those weak points.

Tstuds are a new engineered framing product, essentially framing lumber with an insulated core. Tstuds consist of two long wood 2×3 members connected by crisscrossing dowels factory filled with closed cell spray foam. A 2×6 has an R-5.5 value, where a similarly sized Tstud is R-20 (or equivalent to a 2×6 wall cavity filled with fiberglass batt insulation).

Tstud’s thermal benefits are undoubtedly their main draw. Their closed cell foam core gives it roughly three times as much insulation value as a typical 2×6 bookshelf girt. By framing with Tstud wall girts and filling in wall cavities with batt insulation, there is no need to consider having to add exterior insulation. As long term readers of this column are aware, exterior insulation, for post frame buildings, takes away or eliminates diaphragm strength of steel siding.

Another structural benefit with using Tstuds for bookshelf wall girts is they have engineering tests showing they are up to three times stronger than a #2 graded 2×6!

Now some possible downsides, distribution and availability is highly limited. And (according to Tstud), “We are retailing about the same price as an LVL stud but we are obviously a 5 in 1 solution. In the future we will be about the price as an LSL stud”.

The Home Depot® currently has a 2x4x8 foot LVL stud at $50 or $9375 per thousand board feet. This would make a 12 foot long 2×8 Tstud wall girt roughly $150 or over 11 times more than equivalent sized dimensional lumber. Picking arbitrarily a 36 foot by 48 foot post frame building with a 12 foot eave, this would add nearly $10,000 to your cost of materials! While nifty in design, it is not for the pocketbook faint of heart.

This entry was posted in Pole Barn Structure, Budget, Pole Barn Design, Pole Barn Planning and tagged fiberglass batt insulation, bookshelf girts, bookshelf wall girts, closed cell spray foam insulation, Tstud, thermal benefits on December 3, 2019 by admin.

Overhead Door Header Problems

Overhead Door Header Problems (and More)

Reader MITCH in NASHVILLE writes:

“I recently purchased a property that the previous owner had just built a 30×50 pole barn on. It has foil faced double bubble on the roof and walls. I need to heat and possibly cool the space. What are the options for insulating the ceiling? The ridge is vented. There is no soffit and thus no vent there. The trusses are 5ft apart. Your all-seeing wisdom is appreciated.”

There are times I wish I was not what Mitch feels is “all-seeing”, because I find lots of problems in photos building owners are unaware of.

Back in my post frame building contractor days I would go visit some of our newly constructed buildings, as time and logistics allowed. I generally had very, very good crews and we had an extremely high satisfaction rate from our clients. I would find things wrong (in my eyes anyhow) and send crews out to make repairs. More than once I would field phone calls from clients asking what was going on. They were perfectly happy with their buildings. I would explain to them they might be satisfied, but I was not!

Mitch’s photo shows a frequent challenge posed with post frame buildings where headers (in this case more appropriately known as truss carriers), support trusses between columns. I am not a gambler, but would place money on this not having been an engineered building. Just guessing, this builder used the same size truss carrier for all locations. Usually these truss carriers would be sized to support a single truss centered between two columns. Here, due to door location and width, this carrier supports two trusses, or double what it should have been carrying.

Look back at this photo – there is a noticeable sag across overhead door top! This same sag will be evident along sidewall eave line outside.

Before any thoughts of insulating are considered, a competent professional engineer should be engaged to design an appropriate repair for this header. Engineer should be advised this header will also need to be capable of handling the weight of a ceiling without undue deflection occurring.

Moving forward, contact the roof truss manufacturer to get a truss repair to upgrade trusses to support at least a five psf (pounds per square foot) bottom chord dead load, with 10 psf being even better. Each truss should be stamped with information of who fabricated them.

Once header and truss repairs have been completed, use white duct tape to seal all gaps present in your roof’s radiant reflective barrier. Without these being sealed, there is a potential for warm moist air to get between barrier and roof steel and condensing.

Place ceiling joists on hangers between roof truss bottom chords every two feet. Your previously engaged engineer can verify if 2×4 Standard ceiling joists will be adequate.

Install vents in each gable end. Placed in the top half of each gable, a net free venting area of 360 square inches or more will be required for each endwall.

Hang 5/8” Type X gypsum wallboard on bottom of ceiling joists, leaving an attic access somewhere towards building center. Have a spray foam insulation installer apply closed cell foam along a two foot strip closest to each sidewall. Blow in fiberglass, cellulose or rock wool insulation across remainder of ceiling surface.

This entry was posted in Trusses, Professional Engineer, Pole Barn Questions, About The Pole Barn Guru, Constructing a Pole Building, Pole Building How To Guides and tagged engineer, truss carriers, radiant reflective barrier, closed cell spray foam insulation, type X gypsom wallboard, building deflection, five psf bottom chord dead load on October 17, 2019 by admin.

When Attic Insulation is Baffling

Proper insulation provisions seem to be one of the least considered items when it comes to post frame (pole building) planning.

Here is a case in point from reader JOHN in BEND:

“We have just built a 32’ x 48’ pole building with commercial GIRT construction, metal siding, 4/12 pitch metal roof, concrete floor, 12 ft ceilings located in the high desert region of central Oregon. The building will be used as a training center for a sport shooting club, and only occasionally occupied/heated.

We plan to insulate the walls and (flat) ceiling with R19 fiberglass batts and cover both walls & ceiling with 5/8” drywall. We have some questions/concerns about adequate venting for the attic area above the ceiling. We had a vent-a-ridge installed along the entire length of the building (48ft which will provide about 5 sq ft of roof ventilation). We are now installing 4″ round soffit vents to match the 5 sq ft ridge vent to provide airflow. We had also planned on installing styrofoam soffit/rafter baffles to ensure the fiberglass batts didn’t block the natural airflow from the soffits. Then we noticed that the purlins run horizontally very near to the soffits. The styrofoam baffles appear to be designed for vertical facing rafters that will naturally channel air up towards the vents. Now we are wondering if styrofoam baffles (and our venting scheme in general) will work properly and whether we need to also install gable end vents.

Thanks for the help. We are a volunteer organization and just don’t have the construction expertise.”

From your photo, it appears the ceiling joist closest to the inside of the wall is a 2×6 with airspace above it. If so, your R-19 batt insulation will still have airflow above it. The baffles you invested in should be returned for credit, as they are not applicable for a post frame installation with widely spaced trusses.

Now your true challenge, R-19 insulation is woefully inadequate for your location. Your attic should have at least R-49 (https://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table) which would be about 16″ of blown in insulation.

Normally I would recommend to clients to have raised heel trusses to allow for full insulation thickness. In your case, I would recommend the area in the three to four feet closest to the sidewalls to be insulated with closed cell spray foam on top of the ceiling, to the thickness of the ceiling joists, then blow in fiberglass for the balance of the attic. Do not use faced batt insulation.

This entry was posted in Ventilation, Building Interior, Insulation, Pole Barn Questions, Pole Building How To Guides, Pole Barn Planning, Pole Barn Structure and tagged closed cell foam insulation, closed cell spray foam insulation, attic baffles, pole building baffles, R-49 insulation, batt insulation on July 19, 2019 by admin.

Converting a Pole Barn into a Home

I happen to live in a post-frame home. It was designed to be lived in from day one, so we did not face obstacles in having to convert a pole barn.

Reader DAN in SIDNEY writes:

“I have an existing pole barn that has no current foundation. It looks like 6×6 pt poles right into the ground. I am trying to convert the pole barn into a home and my first task on my list was a foundation. I was told required by code I need a frost protected shallow foundation. My question is what is the best way to add these footers with my poles already in the ground? Do I just pour around it or extend my pour outside the poles a few inches? Thank you for your time.”

Well DAN I will gladly assist with answers to your challenge, however first I might end up bursting your bubble.

Your building itself could very well pose some other challenges. Most often these come from walls not stiff enough (from a deflection standpoint) to prevent cracking of any gypsum wallboard surfaces. This is an area to be looked into by a RDP (Registered Design Professional – architect or engineer) you are going to hire (please nod your head yes).

Chances are excellent roof trusses in your building are not designed to support a ceiling load. If you do not have original sealed truss drawings for your building, you will need to contact whomever fabricated them. Every truss should have an ink stamp stating who manufactured them somewhere along their bottom chord.

Gambrel roof pole barn In many cases it may be possible for an engineered truss repair to be made, to upgrade load carrying capacity of truss bottom chords to a minimum of five psf. I’m sorry to say, this is not free. Truss company’s engineer will need to put his or her license on the line in designing a “fix” for trusses designed for a load other than is now intended. It’s not same as designing original trusses. If you think about it, redesigning and augmenting something you have built, is always more time consuming (and brain challenging!) than first time around. His time and expertise are not without a charge. It’s not usually “much”, like a couple hundred dollars. Then there is cost of materials to do repairs. This will be final out-of-pocket expense if you are doing truss repairs yourself. If not, a contractor’s charge must be added. All totaled, it could run you anywhere from a couple hundred dollars to over a thousand or more.

Siding should probably be removed and reinstalled with a Weather Resistant Barrier underneath, or plan upon using a two inch or thicker flash coat of closed cell spray foam insulation against siding insides. If a dead attic space has been created, attic area needs to be adequately ventilated to prevent condensation. You can find out more about adequate attic ventilation here: https://www.hansenpolebuildings.com/2012/08/ventilation-blows/.

Once you have decided to survive all of the above, let’s deal with your FPSF (Frost Protected Shallow Foundation). This article: https://www.hansenpolebuildings.com/2019/02/minimizing-excavation-in-post-frame-buildings/ addresses an FPSF scenario for new post-frame construction. In your case you can follow along doing essentially the same thing, although your columns are already in ground.

Ultimately your conversions costs may exceed starting from scratch and erecting a new post frame building designed to be your home from start. If this is your case, please call and discuss with a Hansen Pole Buildings’ Designer at (866)200-9657.

This entry was posted in Post Frame Home, Insulation, Pole Barn Questions, Pole Barn Design, Pole Barn Structure, Trusses, Ventilation, Footings, Pole Barn Homes and tagged Frost Protected Shallow Foundation, closed cell spray foam insulation, ceiling load, trusses on April 19, 2019 by admin.

Help Me Insulate My Pole Building

This story is sad, to me. As post frame building “experts” we (an industry collective we) owe it to our clients to educate them at design phase to avoid a situation such as reader ERIC in SPOKANE VALLEY has become happily (or maybe less happy) involved in.

Eric writes:

“I want to start insulating my pole building. 30x40x16, roof layers are metal, synthetic underlayment, osb, 2×8 purlins. My question is, can I leave an air gap between roof and insulation, as I plan on using R19 batting and covering with facing. Has an open ridge vent. Thank you.”

Mike the Pole Barn Guru responds:

Placing batts between purlins is probably not a Top Twenty best answer for several reasons:

If you do not completely fill purlin cavities, Code requires airflow from eave to ridge over top of the insulation. You have no way to achieve this without a major remodel. You don’t even want to go there.

Getting a perfectly sealed vapor barrier under purlins would be nearly impossible to achieve.

You would have to seal the ridge vent (it isn’t working anyhow, because your building does not have an air intake from enclosed vented soffits).

While installing a flat ceiling at truss bottom chord height might appear to be a quick solution, it also is fraught with some perils:

Trusses are probably not designed to support a ceiling load. It might be possible to obtain an engineered repair from the company who produced your building’s trusses.

Ventilation system would need to be addressed for newly created dead attic space.

Closed cell spray foam insulation would need to be added in the area closest to eave sidewalls.

Weighing what you have to start with, my recommendation is to spray three inches of closed cell foam insulation below your roof sheathing. This will provide a greater R value than R19 batts and provides a vapor barrier. You will need to seal off the ridge (foam installer may be able to just spray foam underside).

Also, I notice in your photo what appears to be a total absence of truss web and bottom chord bracing. I’d have to have a copy of your building’s sealed plans, a truss drawing and some more photos to truly discern.

How Could This Have Been Avoided?

Whoever provided this post frame building should have been asking some important questions:

Will you, or anyone who might own this building in future years ever want to climate control (heat, cool or both)?

If yes, what method of roof insulation is being considered? I like insulation over a flat level ceiling personally, as I then no longer pay to heat or cool the attic area. In order to do this right, energy heels (https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/) should be utilized. It also means having adequate attic insulation with soffit vents as intakes and ridge vents as exhaust.

It all could have been so much simpler.