Tag Archives: batt insulation

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.

What Bubble Insulation Brand do you Recommend, if Any?

What Bubble Insulation Brand do you Recommend?

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

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

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

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

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

Dead Air as an Insulator

Dead Air as an Insulator

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

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

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

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

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

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

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

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

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

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

Insulating a Hybrid Building

Insulating a Hybrid Building

Reader COLTON in DAWSON writes:

“Insulation question? I am going with a Worldwide Steel Building. Identical to a Perka. Part of it will be shop and part will be house. It’s a steel web truss with wood purlins and girts. I’m stuck on a lot of guys say just put house wrap on the entire outside or a foil. And batt/roll in the 2’ purlin and girt spacing. And some want to use metal building insulation and roll it on top. I’m not sold on the squashing it in between the tin and possibly causing issues there. I would rather house wrap it and fill in between the purlins and girts with unfaced fiberglass then add a clear vapor barrier inside and then install tin inside the shop and drywall inside the house. Just want your honest opinion since you lived and learned. I enjoy all your helpful information. Thanks!”

My grandson Colton just turned 10 yesterday!

Thank you for your kind words.

You are now faced with what can be a perplexing challenge with a steel framework/wood girts and purlins hybrid building – how to best insulate.

For walls – siding, weather resistant barrier (aka house wrap), unfaced batts, clear poly, interior finish works fine. On your roof, house wrap allows moisture to pass through and be trapped between it and roof steel – possibly causing premature degradation of your roofing. You need a thermal break directly below roof steel. I would recommend an Integral Condensation Control (https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/). If this is not an available option, then a Reflective Radiant Barrier with well-sealed seams will work (we have it in six foot wide rolls with a tab on one side having an adhesive pull strip). Metal Building Insulation can be an effective condensation control under roof steel (provided seams are sealed), however it is difficult to work with, provides limited actual insulation value and can cause your roof steel to pucker. Code requires ventilation from eave-to-ridge above batt insulation between purlins, and there is just no practical way to do it. Instead, place ceiling joists between bottom chords of steel frames and blow in fiberglass insulation. Vent dead attic space above insulation (ideally at eaves as an intake, ridge as an exhaust).

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.

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 BuildingsMy 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.

Creating Extra Work in Barndominium Framing

Creating Extra Work In Barndominium Framing

A supposed downside of post frame (pole barn) buildings for barndominiums is having to frame a wall inside of an exterior wall in order to create an insulation cavity and a way to support interior finishes.

This myth is created and propagated by post frame kit suppliers and post frame builders who do not understand there is a solution – and a very cost effective one (in both labor and materials).

Rather than framing exterior girts (as shown in photo) and then adding vertical stud walls between columns, bookshelf girts can be utilized.

I’ve done several thousand pole buildings using this “bookshelf” or “commercial” girt method. I have two of them myself – in Northeastern WA, so I have a cold climate to contend with.

Use a commercial girt one size larger than wall columns (2×8 on a 6×6 post, etc.), setting commercial girts so 1-1/2″ hangs past the column’s exterior face. Wrap framing with a well sealed high quality Weather Resistant Barrier (for extended reading on Weather Resistant Barriers https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/). 

As an alternative to using a Weather Resistant Barrier, closed cell spray foam can be applied to the interior face of siding as part of a flash-and-batt system https://www.hansenpolebuildings.com/2020/01/flash-and-batt-insulating-barndominium-walls/.

You will find this installation method compensates for any irregularities in column dimensions and creates a deeper insulation cavity. Side benefits – electrical can be run around column exteriors, without a need to drill through them to run wires. On walls a multiple of three feet in length, it also saves having to rip an edge of a panel off either the first or last sheet of steel on a wall.

In either case, block ends of bookshelf commercial girts solid against columns with what is called a “bearing block”.  Take 2×4’s or larger (depends upon engineering) cut 22-1/2” long to fit between commercial girts and install them flat against the post on faces where girts will attach.  Wide face of the block should be flat against the column and aligned with the post edge (not sticking out past column edge unlike girts).   Nail these girt support blocks to columns with a minimum of  two (2)10d galvanized common nails at each end (higher wind loads may require more nails).  This type of nailing is quick and easy and provides a solid support for commercial girt above blocks.  This is a far more solid and stable connection than toe-nailing. Toe-nailing is done by angling a nail upwards from bottom (or downwards from top) of commercial girt, at a 45 degree angle trying to catch enough post edge as the nail goes through to column to hold it there.  Toe-nailing is a very poor connection (and is subject to lots of installation errors).

For maximum cost effective R value, use BIBS insulation. I found it to be cost competitive with installed batt insulation, has a higher R value and completely fills all voids. https://www.hansenpolebuildings.com/2011/11/bibs/

I fondly remember a gal who called me one day asking for “canning jar shelves”…you know like you did before for us.”  Checking our records, I quickly discovered we designed commercial girts on their first building.  They liked them so much – they wanted them again!

Post Frame Condensation and Insulation Challenge

Solving Yet Another Post Frame Condensation and Insulation Challenge

Long time loyal readers will sigh as yet another post frame building has been erected without thoughts to how to properly insulate and control condensation. Had our new friend invested in a Hansen Pole Building, chances are good we would not be having this question and I would have had to write about something else today! Our Building Designers follow with these recommendations: https://www.hansenpolebuildings.com/2019/11/post-frame-building-insulation/.

Our new friend COREY in POST FALLS writes: 

“I have a 36×48 pole building with trusses on 12’ with BCDL 5psf, the roof is plywood sheeted with composition roofing with ridge vent and gable vents. The wall Purlins are on the exterior of the poles and there is no vapor barrier. I would like to install a ceiling with insulation and insulate the walls. I am looking for vapor barrier and insulation recommendations. Was thinking of installing 2×4 on 24 centers to bottom of trusses and installing OSB and blown in insulation, and then framing in between poles adding batt insulation and sheeting with OSB, but am unsure of controlling vapor. Thank you.”

Mike the Pole Barn Guru responds:

Small world, many years ago I graduated from Post Falls High School!

A vented ridge relying upon gable vents as an air intake is usually very inefficient. You should make sure your vents in each end are located in the top half of your attic and have at least 415 square inches of net free ventilating area on each end. This means you are probably going to have to add more vents. Effective ventilation of this area is essential to preventing mold and mildew in your attic.

Wall girts flat on column exteriors are inadequate to carry imposed loads and will not meet deflection limitations. I would suggest you reinforce each of them to create either an “L” or a “T”. Assuming you have 6×6 wall columns, you could place a 2×8 bookshelf style girt on top or bottom of each girt, nailing through 2×8 into existing girts with a 10d common nail at say 12 inches on center. This will create an insulation cavity and allow for easy interior finish.

For ceiling joists between your trusses, 2×4 will not be adequate you should use 2×6 #2 with joist hangers on each end.

Unless you have a Weather Resistant Barrier (https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/) between framing and wall steel, my recommendation would be to have two inches of closed cell insulation spray foam to the inside of wall steel. Then fill balance of wall cavity with BIBs insulation: https://www.hansenpolebuildings.com/2011/11/bibs/ with a well sealed vapor barrier towards the inside space.

Planning for a New Post Frame Home

When it comes to planning for a new post frame home, shouse or barndominium, there are a myriad of questions and concerns to be answered and pondered.

Or, at least I hope you are – rather than just stumbling in blindly!

Reader NICK in NORTH CAROLINA writes:

“Hi, I’m looking into options for building a post frame home in the coming year in NC and wanted to understand more of the details regarding you current building products and suggested techniques.  

Do you provide a means to support the posts on top of the concrete pillars with a bracket vs the post being embedded into the concrete?

Your current package only provides for insulation of the roof, no interior walls, correct?

Can another 2×6 skirt board be added to the inside of the building to isolate the concrete flooring from the post and to provide a cavity for insulation to be installed between the outside/inside girts?

Do you have a listing of contractors that are familiar with your products in given areas that could be used to build the structure?

If using the design service listed for $695, does that include the design for all interior walls/rooms/fixtures as well as electrical/plumbing/mechanical?

Thanks for any information you can provide.”

All good questions. In answer to them:

Yes we can provide plans with a third-party engineered design for bracket set columns, as well as brackets. https://www.hansenpolebuildings.com/2019/05/sturdi-wall-plus-concrete-brackets/

We typically recommend using either a Reflective Radiant Barrier (https://www.hansenpolebuildings.com/2017/05/effective-reflective-insulation/) between roof framing and roof steel, or using roof steel with factory applied Dripstop https://www.hansenpolebuildings.com/2012/11/drip-stop/

We can provide batt insulation for walls and/or ceilings, however there are more energy efficient methods of insulating https://www.hansenpolebuildings.com/2018/06/pole-barn-insulation-oh-so-confusing/

It (extra 2×6 interior splash plank) could, however there are structural advantages to having columns surrounded (constrained) on exterior splash plank interior. (https://www.hansenpolebuildings.com/2018/11/importance-of-constrained-posts/) I’d recommend doing a Frost Protected Shallow Foundation post frame style instead: https://www.hansenpolebuildings.com/2017/09/post-frame-frost-walls/

About Hansen BuildingsAlthough our buildings are designed for an average literate English speaking person to successfully construct their own building (most of them do, and do a wonderful job – because they will read and follow instructions), for those who do need an erector, in many areas we can provide contacts for you to vet.

Our floor plan and elevation package offer (http://www.hansenpolebuildings.com/post-frame-floor-plans/?fbclid=IwAR2ta5IFSxrltv5eAyBVmg-JUsoPfy9hbWtP86svOTPfG1q5pGmfhA7yd5Q)  includes all interior walls, rooms and fixtures. For an added fee you can include electrical/plumbing/mechanical (note: typically all of these last three services can usually be provided at no charge by subcontractors who will be doing these specific trades).

Please feel free to reach out to me at any time with questions. An answer to most questions can also be found at www.HansenPoleBuildings.com by clicking on SEARCH in the upper right hand corner of any page. Type in a word or two and hit ENTER and up pops relevant articles.

Temporary Client Insanity – Truss Problems?

Temporary Client Insanity – Truss Problems? 

Long ago someone told me during the course of any construction project there comes a time when every client goes absolutely bat-pooh crazy. Personally, even knowing what I know, I am guilty of freaking out and having had a case of temporary client insanity during our own remodel and construction projects for our home.

For hyperventilation they have people breath from a brown paper bag, in my case – perhaps a plastic bag over my head and tied tightly about my neck would have been more appropriate.

Below I will share a client’s concerns. He remained much calmer (totally appreciated) during this process than I might have. He wrote to Justine (Hansen Pole Buildings’ Master of All Things Trusses):

“Justine, one more thing, the top chords of the trusses show 2×8 and the trusses were delivered with a 2×6 top chord, so all the bracing (purlins) will be hanging down. This roof is going to be insulated.

Also, the double trusses are not fastened together and I think I should have more than 1 set of scissored trusses.”

Our Technical Support response:

Building plans are drafted prior to receipt of truss drawings, so trusses as drawn on your plans are merely a depiction of what they may look like. Top and bottom chords as well as internal diagonal webs may be entirely different. The roof slopes will be accurate. Your building’s roof purlins certainly may hang below roof truss top chords, as this has no bearing upon your ability to insulate (please refer to Figure 9-5 of your Hansen Pole Buildings’ Construction Manual). As your roof has a Reflective Radiant Barrier, if you intend to use batt insulation between purlins, make sure to use unfaced insulation without a vapor barrier on underside, otherwise moisture can become trapped between two vapor barriers. This can lead to ineffective damp insulation as well as potential mold and mildew issues.

Per change order #3 your building is to have standard trusses in front 24 feet and a vaulted ceiling in rear 24 feet. With a pair of scissor trusses at 12 feet in front of rear endwall, this allows for the rear 24 feet to be vaulted and front 24 feet to have a level bottom chord.

Truss assembly people are not carpenters – and rarely do truss manufacturing facilities even have nail guns. It also avoids nail wounds from inexperienced or inappropriate use. As an example – back in 1979, I was shopping for a new employer designing and selling trusses. I interviewed with Tilden Truss, near Seattle. They used air guns firing a “T” staple to initially set steel truss plates. Their fabrication shop ceiling was covered with hundreds (if not thousands) of these “T” staples!

You will find it much easier to maneuver single trusses around your building site, than twice as heavy double trusses.

Please feel free to address any building assembly concerns to TechSupport@HansenPoleBuildings.com.

Another crisis averted.

Spray Foam Advantages Over Batt Insulation

Once again – confession time. I’ve never personally used spray foam insulation.

My oldest stepson, Jake, teaches high school chemistry and physics. He is one smart dude, as he has a master’s degree. When he added onto what was formerly his grandparent’s home, in the Browns Valley, MN area, he utilized closed cell spray foam insulation.

Not only is Jake smart, but he is also frugal, which tells me he did his research and compared costs of not only the original installation, but also savings over time.

Polyurethane foam insulation is available in closed-cell and open-cell formulas. With closed-cell foam, the high-density cells are closed and filled with a gas which helps the foam expand to fill the spaces around it. Open-cell foam cells are not as dense and are filled with air, which gives the insulation a spongy texture.

Polyurethane and isocyanate foams are applied as a two-component mixture which comes together at the tip of a spray gun, and forms an expanding material. While open-cell foams typically have R-values of 3.5 per inch, closed-cell foams can attain R-values of 7 per inch. Closed-cell foam is very strong, and structurally reinforces the insulated surface. By contrast, open-cell foam is soft when cured, with little structural strength. However, it provides superior sound resistance and allows timber to breathe. It is also fire-resistant and won’t sustain a flame.

insulation-rollSpray foam insulation costs more than batt insulation, but it has higher R-values. It also forms an air barrier, which can eliminate some other weatherizing tasks, such as caulking. This plastic insulation goes on as a liquid and expands to fill the available space, sealing all gaps and cracks and stopping any air leaks (This can also keep out bugs or other vermin). Another advantage is foam can fill wall cavities in finished walls without tearing the walls apart (as required with batts). It also provides acoustical insulation and increases structural stability. When building a new post frame building, this type of insulation helps reduce construction time and the number of specialized contractors, which in turn saves money.

The cost can be high compared to traditional insulation; however, open cell foams provide a better economical ratio. Open-cell foam is $1 to $1.20 per sq. ft. while closed-cell foam is $1.75 to $3 per sq. ft. (for a 2-by-4-framed wall). Both require professional installation.

Here is an earlier example of the investments into each: https://www.hansenpolebuildings.com/2014/02/insulation-foam-fiberglass/

Although for moisture control closed-cell foam is non-porous, open-cell requires a vapor barrier; however, the added cost of closed-cell foam may not be as advantageous as vapor barriers are usually required by building codes, regardless of the type of insulation used. Also, closed-cell polyurethane insulation levels can drop over time as some of the low-conductivity gas escapes and air replaces it in a phenomenon known as thermal drift.

In summary, DIY people use fiberglass as it is readily available, maintains a reasonable price ratio and is easy to install. Although it is not as easy to sustain the higher performance required by today’s insulation standards over time. It is also a health hazard. Most tract homes also use fiberglass insulation for the same reasons. However, the installation experience of the contractors can improve the overall performance.

Higher-end tract homes and custom homes tend to use the cellulose and foam solutions. They provide a superior insulation level and a number of other advantages, including air and vapor blocking, noise reduction and insect minimization.

As with all things, you get what you pay for and you can pay up front or pay later. There is no shortcut to energy efficiency and saving money.

We will be adding an elevator shaft to our own post frame building home later this summer. Although it is not a large footprint area, it will be over 30 feet tall and keeping it the temperature of the rest of the building will be a high priority – so I will be investigating spray foam myself.

Shop Insulation

I really enjoy the Hansen Pole Buildings’ Designers. They honestly want to know, and in our industry there is a lot to know. A typical day for a Building Designer can run the gamut from the farm, to the office, home or the store as well as enjoying clients from everywhere in the country.

BInsulated Buildinguilding Designer Doug asked, I’m sorry to keep beating the insulation horse, but I have a client who wants to put up a 60×100 building on his timberland. I asked him about heating it and he wants to put a wood stove in it. So he wants to heat it occasionally. It’s in Clackamas County, OR, so it will get cold. 

 If this were your building and you wanted it to be cost and wood-stove effective, what would you do?

 I’m tempted to give him one quote with reflective roof insulation and house wrap, and one with full batt insulation. Am I going down the right road here?

 Thank you for your help.”

 I so appreciate being asked how I would do something. Me – I am frugal, but I will do it right. And most aesthetic elements of pole buildings also have a function and add value for the investment.

My response to Doug: I rarely heat mine, but I did it right, so no one will ever need to mess with it. And the resale is huge from a well done garage.

Me (this is exactly what I did too)….I would commercial girt the walls, use housewrap on outside and BIBs insulation on the walls; ceiling – ceiling load plus ceiling joists, raised heel trusses (means eave height needs to be taller), vented overhangs & ridge, blow in R-60 fiberglass over 5/8″ Type X drywall.

I didn’t do it just because I could, or could afford it – it was about doing it right.”

 Read more about climate control here: https://www.hansenpolebuildings.com/blog/2012/04/climate-controlled/

 The cost of a building, is in deciding to do it at all. Once this hurdle has been crossed I always encourage clients to build the largest building which is economically feasible and will fit on your site. You only get one chance to do it right or wrong – please, if at all possible do it “right”.

Are the Poles Close Enough?

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

Email all questions to: PoleBarnGuru@HansenPoleBuildings.com

DEAR POLE BARN GURU:How close is close enough for pole placement? After setting and leveling poles to the string, the poles on one side of the barn are 1/2″ off (lengthwise) from the other side. Is this close enough? KARMIC IN KANSAS CITY

DEAR KARMIC: There actually exists a document entitled, “Accepted Practices for Post-Frame Building Construction: Framing Tolerances”. In the document, in Section 6.4: “Wall length. In rectangular buildings, the overall length of opposing walls should not differ by more than 2.0 inches.”

In my humble opinion “only” two inches would be a HUGE difference. Variations such as this need to be hidden somewhere and two inches would be huge.

In your particular case, if the poles are merely placed in the holes and braced, I would recommend adjusting a corner column to get equal overall lengths.

If the columns have been set in concrete, it is best to then make the overall dimensions at the roofline correct. This will make squaring up the roof to install roofing far easier. In the event this circumstance is the choice, when it comes time to do the siding, plumb the corner(s) which are most likely to be noticed.

On the out-of-plumb corners, the edge of the corner trim will not align with the steel ribs (there will be a ½ inch variation from top to bottom). Most people will never see it – but putting it on the least viewed corner reduces the probability.

DEAR POLE BARN GURU: Hi: How do I install fiberglass batts of R 19 in my walls of pole barn without touching the metal walls? Thanks. ART IN ALBION

DEAR ART: The easiest way would be to install a quality housewrap over the outside of the wall girts and under the wall steel before siding it.

In the event your pole building has been sided, there really is not a negative effect in the event the fiberglass happens to be in contact with the wall steel. It IS essential to have a vapor barrier on the inside of the insulation which provides a total seal. If the vapor barrier is not completely sealed moisture will escape into the wall cavity, and be trapped by the steel siding. When the siding is cold enough, condensation will form, saturating the fiberglass and reducing its efficiency.

You may want to read more on climate controlled pole buildings at:

https://www.hansenpolebuildings.com/blog/2012/04/climate-controlled/

DEAR POLE BARN GURU:What about putting the concrete up to the slab level?

CONCRETING IN CANTON

DEAR CONCRETING: I will assume your question is in regards to backfilling the columns. If so, there is no documented negative reason (lots of old wives’ tales) to not fill the holes entirely with concrete – other than cost (concrete can become expensive backfill). It will make your building very resistant to uplift forces.

Thermography Proves Energy Efficiency of Post Frame Buildings

Thermal Image of HomeThe National Frame Building Association (NFBA) commissioned a report, which was produced in May 2010, to illustrate point of heat transfer in different types of buildings using thermographic images. Both builders and registered design professionals (architects and engineers) familiar with post frame buildings know these buildings use fewer structural components to create an exceptionally economical, energy efficient and environmentally friendly building. With fewer required structural members, wide spaces are created between wall columns, with fewer breaks in insulation.  As well, wood has natural insulating properties compared to steel or masonry structural components.

Post frame has been believed to reduce some of the heat transfer observed in other construction methods, due to wider insulation cavities and less thermal bridging. To confirm these concepts, thermal images which provided visual examples of heat transfer were captured. These images highlight inefficiencies which may be caused by the thermal bridging effects of nonwood structural components, compressed insulation and interruptions in contiguous insulation.  The authors felt some of the examples could be improved with additional measures, which would further distinguish their construction costs compared to those for post frame.

The report covered a very small sampling of commercial buildings – post frame, wood stud framed, masonry and steel framed.

Surface temperature variations which appear using thermography of building envelopes can be due to variations in the thermal conductivity (or thermal resistance) of materials, and/or air movement (and hence heat transfer by convection). Other sources of variation include reflective and wet surfaces. Air movement through a thermal envelope is known as air infiltration when air moves from outside to inside, or air exfiltration when air moves from inside to outside.

Thermal imagining does not quantify heat transfer; it just indicates regions of elevated heat gain or loss.

The post frame building investigated using thermography had R-19 fiberglass wall insulation, R-38 cellulose ceiling insulation and R-8.1 polystyrene perimeter foundation insulation.

Air infiltration points appeared to occur at electrical and plumbing penetrations, which can be resolved with minor measures taken prior to construction completion.

The all steel building had R-19 fiberglass insulation in the roof and walls and no foundation insulation. The building was found to have major air leakage points, enough so it was impossible to depressurize it to determine air infiltration points.

Thermography of the all steel building showed surface temperature drop as the thickness of roof insulation decreased near each roof purlin, with the lowest temperatures occurring where the insulation is compressed by the eave strut. A similar temperature profile was observed at each wall column. Lower surface temperatures were also located near the base plates, due to lack of foundation perimeter insulation.

The masonry building measured had untreated concrete block walls, other than an office portion furred in with 2×2 lumber and insulated with R-5.8 fiberglass batts. Ceilings had R-19 fiberglass batts, with no perimeter foundation insulation.

The studwall building was a restaurant with 4,125 square feet of conditioned space. Insulation was R-11 fiberglass wall batts and R-38 cellulose in ceilings. The foundation perimeter was non-insulated. This building was relatively “leaky” from an air infiltration standpoint, with measureable air infiltration at the bottom and top wall plates, as well as at penetrations.

Lower surface temperatures were seen at the wall studs, where the heat loss through framing (depending upon size and spacing of the studs) can vary from 33 to 49 percent of the total.

This study underscored the importance of sealing cracks or spaces between framing materials in a buildings thermal envelope and showed both the measurable difference a small amount of insulation can make and the impact of compressing fiberglass insulation.

Finally, this study showed a uniformly insulated thermal envelope is readily achievable with post-frame construction. There are fewer breaks in insulation where bridging may occur compared to stud-framed structures. Wood structural components do not conduct heat as readily as steel or masonry structural components. Wood posts and heavy trusses used for post-frame require fewer structural materials to be installed, so fewer materials are required. The primary building materials are renewable wood structural components and recyclable steel or other types of cladding. Thermography helps illustrate where thermal bridging may occur. Given these factors and the comparatively low cost of post-frame buildings, post-frame construction may be among the most cost-effective ways to build for sustainability and energy efficiency.

Dear Guru: Which Insulation Should I Use in My Metal Pole Building?

DEAR POLE BARN GURU:  I have a few questions that you might be able to easily answer.

I have a metal pole building wood framed. Most of it has the standard Condensation/insulation blanket in it however some of it got damaged by mice and had to be ripped out. We are now trying to finish that area of the building to use as an office, Heated but NO A/C.

To make this a little more complicated the room is already pre-framed out to add extra insulation, this framing is now blocking any good access to the beams and girts that are structural (I have pictures but don’t know how to attach).

When talking to insulation contractors I have gotten mixed and conflicting information, I am not sure how much they know about insulating metal buildings.

How to insulate?

1. Can I use Fiberglass batts then cover with a vapor barrier and sheetrock? (The wood framing would be in the fiberglass batts) If I can… do I leave space between the fiber glass and the metal or do I want the insulation to be in contact with the metal and fill the wall as much as possible? (One insulation guy said to PACK it as full as possible with NO air gaps)

2. If the Fiberglass will not work properly installed this way, (condensation problems?) would I want to use 2″ closed cell Spray foam? Would the spray foam cause any damage or issues with the metal siding?

3. Should I do this a totally different way than I have asked?

4. Is there any issue to adding Fiberglass bats insulation between the purlins, in effect creating a hot roof. KITSAP KELSEY

DEAR KELSEY: You’ve made some good progress getting everything stripped down to the point you are at.

 One wall at a time, I would remove the wall steel and install a quality housewrap. Make sure to leave enough to tightly cover around corners. You may be surprised at how quickly this can be done and the siding reinstalled. It is a good idea to use larger diameter/larger diameter screws to reattach.

 Rather than batt insulation, install BIBS insulation. It will completely fill any voids and give a higher R value than batts.

 Packing batt insulation in as tightly as possible would severely reduce the R value of the batts. Fiberglass batt insulation is effective only when not compressed – it is the dead air trapped within the fibers which gives the R value, not the fiberglass itself.

 Placing batts between the roof purlins is not a good idea. The Code requires insulation batts in vaulted ceilings to have continuous air flow (ventilation) above the batts. Even if say 3-1/2” insulation was placed between them, the dead air above the fiberglass would be trapped between the purlins, taking away any possible airflow (not to mention having to also have sufficient ventilation at the eaves and the ridge). It would also create an airspace trapped between two vapor barriers, the condensation control blanket insulation between the purlins and the roof steel, as well as the facing of the batts.

DEAR POLE BARN GURU: I am planning to build a pole barn. I want to build it on the side of a hill with one side built into the hill. I would like to build into the hill to a depth resulting with about a 5 ft earthbag wall with crusher run limestone in the bags. A french drain would be put on the outside with some crushed rock to relieve hydraulic pressure. I would like some ideas on how to interface the poles to the earthbag partial wall. Would buttresses be needed? I can cut some red oak lumber on my portable sawmill for the sill on top of the earthbags or do a concrete beam. If the poles are 6”, and are set in the center of the bag, how do I get the siding to shed water on the outside of the bags. I know I will need to put girts on the poles for siding but they typically aren’t more than 2x4s. Looking for ideas. EARTHBAG

DEAR EARTHBAG: Post frame buildings, are by their very nature probably the easiest building for an individual to construct on their own. My first thought is why take something so simple, and make it more difficult than it has to be? Not to mention the many additional costs you have outlined.

Rather than trying to incorporate the earthbags into the building itself, why not just build an independent retaining wall away from the building? This would eliminate so many potential issues and would make the pole building construction easy, as it should be.

And Now…Insulation Crime!

If you didn’t read yesterday’s blog – is good to catch up as a lead-in for today – well worth the time.  In it I discussed a problem a reader had asked for tech support about an insulation issue.

So today – yet another reader has written….

“I am in the process of finishing a pole building. The building will be used as my workshop and it will be heated, I live in Washington State. The contractor that put up the exterior placed R-23 Kraft Faced fiberglass insulation between the 2 X 6 rafters with the facing against the metal corrugated roof. This means that the vapor barrier is facing the roof, not the inside of my building. I plan to install sheetrock on the ceiling. It is not uncommon for the temperature to dip below zero here, and in the summer reach 100 for a month or more. My question is can I place a 4 mil poly vapor barrier on the interior side of the roof thereby wrapping the fiberglass insulation in two vapor barriers?”

What this building owner has is a pole building with 2×6 roof purlins on edge. Condensation on the inside of steel roofing applied directly on top of purlins can be an issue. This particular builder errantly installed batt insulation with the vapor barrier towards the steel, in efforts to reduce or eliminate the condensation problem.

If the builder would have properly installed the insulation between the purlins, with the Kraft facing towards the climate controlled area, making sure all seams were sealed, it would have been both effective as insulation and the vapor barrier would have kept the warm moist air inside the building, from condensing on the underside of the roof steel.

Why do I call this scenario “insulation crime”?  Because the builder took his client’s hard earned money and in return, gave him nothing but a problem to be solved.

Nearly every jurisdiction in the state of Washington requires both a Building Permit as well as the inspection of new buildings under construction. If this was a permitted building, the Building Inspector should have noticed the improper insulation installation and issued a correction notice – rather than signing off on a final inspection.

Fiberglass Insulation is Boring

Fiberglass insulation is difficult to write about. In my opinion just about everyone knows about this topic or how the product works. There just isn’t much sizzle to the topic. I would hate to work for an advertising agency or public relations firm having to write about this stuff on a weekly or monthly basis! What can you say about fiberglass to excite potential pole building owners or contractors?

I actually started researching fiberglass insulation when questioned by a Building Official as to the amount of weight it would add to a roof system. Fiberglass is a very lightweight material. In this particular case, to obtain an R-factor of 49, it would take 20-1/2 inches of blown in fiberglass. Installed with the proper density, this thickness adds a weight of only .922 pounds per square foot. This means every inch of fiberglass insulation is adding only .045 pounds of weight!

This kind of weight will not overload average ceiling materials. The biggest concern – proper installation of ceiling drywall. Often drywall hangers do not install enough screws in ceilings (note – screws, not nails). A minimum of five screws need to be used across a four foot wide panel. This means one at each edge and then spaced every foot across the panel. It is essential to not tear through the drywall paper, so do not count any screws which do.

I wondered if flow-through ventilation for attics actually sucked air and heat from attic fiberglass insulation (all attic spaces require ventilation, by Building Code). According to the experts, batt insulation does not suffer from convective heat loss. Blown-in fiberglass, however, can suffer minimal heat loss in very cold regions. This loss only begins to happen when attic temperatures drop below freezing.

How about the R-factors of batts vs. blown-in fiberglass insulation? It didn’t surprise me to find out batts are better insulators. The primary reason for this is the tight tolerances found in the manufacturing process. Batts are uniform. The placement and quantity of the glass fibers can be controlled. This is not the case with blown-in fiberglass. The density of the material is controlled by the installer and settings in the machinery used to blow in the fiberglass.

What happens if the roof leaks? Fiberglass attic insulation is not ruined by water. It will retain its R-value once it dries. However, moisture may cause mildew and mold problems, so it is essential to speed the drying process. You may need to set up fans or heat the area, just like drying out carpet.

Wall insulation (and drywall), which is saturated from flood waters must be removed and properly disposed of. Flood waters potentially contain massive amounts of bacteria which will very probably cause a “sick house” if not remediated. Consult with your local health department for proper steps in treating your “sick house”.

While both batt and blow-in fiberglass insulation are made from the same material, they clearly have distinct applications.  Light, relatively easy to install, they perform an important function in your pole building.  Yes, they “fly under the radar” and quite frankly, may be considered “boring” to some of us, but I’d not want to live in minus 40 degree weather without them!

Fiberglass insulation in pole buildings

The best time to insulate your new pole building…is at the time of construction. There are many building features which are more easily done at time of construction, but sometimes the old pocketbook only stretches so far.

At the very least, if you can prepare your building for future “additions” of features such as additional doors, windows, and insulation, you will be time and money ahead.  In the building planning stage, one of the “lists” you might want to make in order to make the best decisions in designing and ordering your new pole barn, is “what are all the possible uses of my building going to be?”  I’m talking not just in the next few months, but way down the road, like even five or more years from now.

Many times what starts out as a simple accessory building, becomes so much more. With the recent challenges for folks selling and purchasing properties and homes, I’ve seen a huge surge in clients building their garage/accessory building on a new building site before they even think about building their new home.  Whether due to waiting to have the former house and real estate sold, or just not enough cash flow to make it all happen at once, more clients have been opting to insulate their pole buildings and live in them while the rest of their plans come to light.

With this in mind, designing for insulation is important.  On my most recent personal building, for example, knowing I wanted to be comfortable in shirtsleeves in -40 degree weather, (and not pay to heat the outside world), I chose to put in deeper outside walls of my building than were necessary by code, to accept a thicker insulation I also put in fiberglass insulation within the interior walls, as part of the building was “cold storage” separating the warmer areas by interior walls.  So let’s talk about fiberglass insulation.

Fiberglass itself is not some “magic” insulator, it is the dead air trapped in the fiberglass which is doing the work. Smash the air out, and you lose R value.

This is not to say fiberglass insulation, is still not one of the most affordable and best insulation choices.  Sometimes it just comes down to two questions: 1. Will it do what I want it to?  And 2. Will the cost of the product and installation be a good investment over time?

With proper advance structural planning, roof purlins and wall girts can be spaced at 24 inches on center. This will facilitate the later installation of batt insulation. Properly installed, this method can be effective for maintaining a controlled climate within the building. Installation of kraft (paper faced) fiberglass insulation is relatively quick, as it is manufactured with staple tabs along the sides of the rolls for easy application. Many professional installers prefer to use unfaced insulation and add a clear vinyl visqueen vapor barrier to the inside of the fiberglass/framing assembly. In either case, with a tight seal it is clean, neat and contributes to mold prevention and pest control.

I would be remiss if I didn’t advise you to be safety conscious during installation.  Put on protective gloves, a dust mask and goggles when working with insulation. Insulation is made of tiny fiberglass shards, which can cause serious irritation of the skin, eyes, nose and throat if you don’t take proper precautions.

Overall fiberglass insulation batts remain an easy to install option and affordable choice for condensation, climate, mold and pest control.