Tag Archives: fiberglass insulation

Cellulose for a Pole Barn Attic

Multiple options are available for insulating attics of post frame (pole barn) attics. Reader NATE in BURNHAM writes:

“Hello! I have been doing some research all evening and I can’t seem to find an answer. I did take the time to read some various forums and blogs regarding this subject to no avail…having said that, here is my question; According to the attached spec sheet for my roof trusses (4ft O.C) spanning my 52Lx28Wx10H pole building, would blown in cellulose insulation at an R38 value combined with 6ml plastic sheeting (vapor barrier) and thin gauge metal ceiling be supported? I do know from the specs that my BCDL is 5psf. Any help on this would be wonderful as I am at a stopping point in finishing my garage. Thank you!”

Mike the Pole Barn Guru advises:

I am going to hopefully change some of your plans here….

Unless your building is where there are 8000 heating degree days or more, you should not have a ceiling vapor barrier (no 6ml plastic sheeting). In Pennsylvania you are well under this requirement (Northern Minnesota would qualify). You do need to have sufficient eave intake and ridge exhaust ventilation to allow warm moist air from inside of your building to be vented out above your insulation. Your total NFVA (Net Free Ventilation Area) must be no less than 699 square inches, with at least 50% and no more than 60% located at the sidewall eaves.

Blown in cellulose weighs roughly 2.5 to 3 pcf (pounds per cubic foot). Blown in cellulose will settle as much as 20% and can take up to two years to do so. Cellulose gives R-3.5 per inch, so your R-38 would be 10.86 inches thick (after settle), so I would plan on no less than 13.5 inches blown in to achieve your R-38. To be safe, I would assume 3.4 psf (pounds per square foot). Besides settling, blown cellulose does have another downside – in order to be fire retardant it is treated with borax or boric acid. Borates can be corrosive to steel in humid or moist environments, so you may want to consider a different insulation type, such as fiberglass. Fiberglass is also lighter weight, coming in at about a pound per cubic foot.

Steel liner panels are most typically 29 gauge steel weighing in around 0.6 psf.

Your five psf BCDL (bottom chord dead load) has to also account, in part, for weight of your trusses and bottom chord bracing, as well as any electrical and light fixtures. Most often this is considered to be a pound per square foot. This is going to put your proposed use of cellulose right at capacity, without any remaining margin for error.

Decisions, Decisions – Vapor Barrier for a Post Frame Steel Reroof

Decisions, Decisions – Vapor Barrier for a Post Frame Steel Reroof

There are few reasons to replace an existing post frame building’s steel roof, as properly installed it should last a lifetime. Among these reasons could be:

Tired of Existing Color
Old roofing was nailed on
Tree fell through roof

This last one actually occurred to our shouse (shop/house) when I lived in Northeast Washington!

Loyal reader and Hansen Pole Buildings’ client MIKE in COUPEVILLE writes:

Reflective Insulation“I am currently re-siding/re-roofing an existing pole building in order to match the exterior of the building I recently purchased from you.  This building is roughly 32 x34 and the roof purlins are 2×6 on end roughly every 2 feet.  I’m using Fabral’s grand rib 3 29ga for the roof and it will have fully vented soffit overhangs and a vented ridge cap.  I am trying to figure out what I’m going to do for at least a vapor barrier under the roof steel, I see you seem to recommend foil faced bubble insulation but that is not very common in my area.  I am seeing a lot of people using lamtec wmp-vrr (fiberglass insulation with a poly backing)  3″ thick and I believe they lay these wide rolls on top of the purlins and then place the metal roofing on top of that then screw down the roofing compressing the fiberglass insulation between the metal roofing and the purlins.  Have you seen this style of insulating before?  Do you think it is an acceptable way of doing it?  I see as killing two birds with one stone.  I may be insulating this shop in the future so if I do then the roof is already insulated plus I believe it acts as a vapor barrier which is the main reason to do it as I don’t want any condensation dripping down on the inside of the shop.  I live in the Seattle area if that helps to know what my climate is like.  Thanks in advance for your input.” 

Mike the Pole Barn Guru responds:

Our recommendation would be to order your roof steel with factory applied I.C.C. (https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/).

Metal Building Insulation (fiberglass with a vinyl facing) is a decent condensation control, provided all of the seams are tightly sealed. It is a pain to work with, provides very little effective insulation value and makes your roofing pucker outwards between purlins https://www.hansenpolebuildings.com/2011/11/metal-building-insulation-in-pole-buildings-part-i/.

If it is too late for an I.C.C. then the radiant reflective barrier (https://www.hansenpolebuildings.com/2017/05/effective-reflective-insulation/)

 is probably your best option.  Order in six foot width rolls to minimize seams and make sure to get a product including a tab along one edge with an adhesive pull strip attached.

How Best to Use Metal Building Insulation

How To Best Use Metal Building Insulation

Loyal reader ANDY in SOUTH CAROLINA writes:

“ I read with interest the article “What house wrap is good for” on your website and would like to include house wrap on a pole building I’m currently planning to build in the upstate of South Carolina.  Typically builders in that area simply use 3” polypropylene faced fiberglass insulation between the wall girts and steel siding. My situation is a bit different than most I have seen in that my single story building will be 1500 sq ft total, with 900ft dedicated to garage and shop space, and 600 ft dedicated to a guest apartment. If I were to place house wrap between the girts and steel as I believe you recommend, could the 3 inch faced insulation simply be placed on the inside of the girts for the garage space, and significantly more fiberglass insulation used around the apartment – inside deeper cavities of flush walls?  

Thank you.”

For those of you who need to know, here is article referenced by Andy: https://www.hansenpolebuildings.com/2012/11/house-wrap/

Surprisingly there are a lot of builders who “sell” people on how valuable a benefit Metal Building Insulation is. Long time readers may recall my personal adventures with it: https://www.hansenpolebuildings.com/2011/11/metal-building-insulation-in-pole-buildings-part-i/

Three inch thick Metal Building Insulation makes for a very poor return on investment as every time it crosses a wall girt it gets compressed pretty well to R-0. If lucky, one might net an R-3 or so out of it. It also tends to cause steel siding to pucker outward between girts. Properly sealed, it does make for a decent condensation control.

My recommendation would be to place a well-sealed WRB (Weather Resistant Barrier) between all wall framing and siding. Use commercial style bookshelf girts to create an insulation cavity https://www.hansenpolebuildings.com/2020/05/how-to-install-bookshelf-girts-for-insulation/. Use unfaced batt insulation with a minimum 6 mil clear visqueen vapor barrier on the inside. For what you would pay for three inch Metal Building Insulation, you can completely fill your insulation cavities.

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.

Worldwide Steel Buildings or Post Frame?

Loyal reader STEPHEN in AUSTIN writes:

“Mike –  I am so thankful for all the info you and your company have provided over the years. Your experience and knowledge have helped so many.  I especially love your promotion of bookshelf girts.  Every time I see a building framed within a building, I ask why?  Bookshelf girts make so much sense.  In my research, I also came across Worldwide Buildings, a competitor of yours.  They have a similar system:  https://youtu.be/yilRYwxukRQ

What would you see as some of the cons to their setup?  I am assuming cost is probably the biggest drawback.  Anything else?  I would plan on foam board (Possibly as a WRB as well that is taped) for any structure for a thermal break, whether it is steel or wood.  Any input you could give would be appreciated.”

Mike the Pole Barn Guru comments:

Thank you very much for your kind words. My goal is to see to it people avoid making crucial mistakes so they end up with buildings best meeting their wants and needs, and be as ideal as possible – even if they are not Hansen Pole Buildings.

Until recently my son Adam, his wife and our grandson lived in Austin, TX we are in a small world!

Bookshelf wall girts solve so many potential challenges and seem like a fairly obvious design solution to me. I also scratch my head when I see people framing up a house inside of a PEMB (pre-engineered metal building.).

I do know some of Worldwide’s staff, have met them in person, and they certainly seem like good people. I have no idea what sort of an investment comparison there is. Our buildings do come complete with engineer sealed drawings and sealed verifying calculations including a foundation plan, where these would be extras elsewhere. It does appear you would need some degree of precision in placing steel frame bolts. They also may have some additional expense involved with their slabs (usually PEMB slabs require a significant amount of rebar). 

Steel frameworks are great transfers of thermal energy – you would want to significantly isolate them with insulation having as great an R value as you would be using in your roof and walls. I see a lot of vinyl backed fiberglass insulation being applied on their website. This is not a very effective insulator as it gets crushed down to nothing at any purlin. For walls, you want a WRB (Weather Resistant Barrier) allowing any moisture inside walls to escape outward, so this vinyl backing would not be ideal. 

Foam board insulation should not be placed between framing and siding as it will allow your building’s siding to shift with wind and over time will cause deformation of screw shanks and/or elongate screw holes and eventually cause leaks. Ideally you would glue any foam insulation boards on the interior side of framing (to prevent thermal transfer from screws), taping all joints and sealing to concrete slab.

On their website they show girt clips on their frames for supporting 2×4 bookshelf wall girts – making for a fairly shallow insulation cavity. As near as I can tell, their packages do not include any lumber for girts, purlins, etc., merely steel frames, roofing and siding.

Thank you again for being an avid reader, please continue asking any questions.

Will I Have Moisture Issues?

Condensation and moisture issues in any building can be problematic. No one purposely designs a building with an idea to have dripping from under roof condensation, or mold and mildew from trapped moisture.

Hansen Pole Buildings’ client and loyal reader KURT in SAINT HELENS writes:

Question about roof insulation. Plan on insulating 2″ double-laminated with WMP-VR on one side and FSK-HD Foil facing on the other. Layers for the roof will consist of metal roofing, 30# roofing felt, 1/2 plywood and the insulation. Will I have moisture issues with this configuration?
Thanks for your input.”

Mike the Pole Barn Guru responds:

Thank you for your question Kurt, obviously you have given a great deal of thought to condensation and moisture issues in your new post frame building.

Your layer of plywood and felt will provide a thermal break preventing any warm moist air inside of your building from contacting with a cooler steel roof. 

For those interested, here is some light reading about WMP-VR https://www.hansenpolebuildings.com/2014/10/metal-building-insulation-2/, a faced metal building “insulation”.

FSK facing, or foil-scrim-kraft is a flame retardant vapor-barrier. It is one of the most commonly used facings in today’s insulation industry. During manufacturing processes of an FSK facing, a layer of lightweight aluminum foil is layered against a tri-directional, reinforcing fiberglass scrim (yarn) and then paired with a final layer of natural brown kraft paper. This is all laminated together using a flame-retardant adhesive.

Once this process is complete, facing is rolled into a giant master roll and delivered to a fiberglass manufacturing facility. This is where manufactured fiberglass insulation is adhered to facing’s kraft paper side. 

FSK facing is most commonly utilized with duct wrap, duct board, and mechanical spin-glas boards on outward-facing, exposed surfaces of HVAC ductwork. This FSK facing not only serves as a vapor-barrier to facilitate condensation control, but it is also a protective barrier for fiberglass insulation itself. Aluminum foil gives FSK its distinctive silver color and can typically be easily recognized on any HVAC system.

This two inch thick metal building “insulation” is going to be an unnecessary expense and will provide little or no actual insulating value. As long as you have adequate ventilation (both intake and exhaust) and your concrete floor has a well- sealed high quality vapor barrier below it, you should not experience moisture issues. Keep in mind – in the months immediately following pouring your concrete slab, expect to have excess moisture within your building. Once your concrete floor has cured, these issues should go away.

Insulation Values Reflect Real-World Energy Performance?

Insulation R Values Reflect Real-World Energy Performance?

Energy efficiency has become huge for post frame building construction. More and more people are discovering post frame buildings as being a cost effective design solution for residential and commercial construction.

Long time readers of this column have seen article after article in this vein, increasing with time. You have also had an opportunity to witness questions from many current post frame building owners who wished they would have designed appropriately to begin with. Proper advance planning can certainly help to achieve desired results.

Let us assume, for a moment, you have created a post frame building with commercial 2×8 bookshelf wall girts and 22 inch high raised heel trusses. In your walls, BIBs https://www.hansenpolebuildings.com/2011/11/bibs/) fiberglass insulation 7-1/4” deep has been used. This will give a laboratory R value somewhere in excess of 30. In attic space, 20 inches of blown in fiberglass will provide a R value of over 60. You have done your work and are happy your decision will give a more than satisfactory end resultant.

Then along I come and poke holes in your investment.

Keep in mind, my very own post frame home has fiberglass insulation very much like our imaginary scenario above.

The most common yardstick for measuring insulation performance will be R value, but there’s a problem. Insulation packaging shows lab analysis of R values, but it’s based upon used testing completely eliminating air movement from results. This matters a lot with fluffy insulation materials because air movement greatly lowers real-world insulation performance. Drafts and air currents often happen within wall cavities and attics and this will be why real-world insulation performance can be significantly lower than advertised values.

Alternatively, insulation products not allowing air movement through them (spray foams and rigid foams, for instance) have real-world insulation values almost identical to what you see printed upon packaging and used in advertising. Their performance doesn’t decline. Air-impervious insulations can be more than twice as effective as air-porous insulations of identical R value under real-world conditions.

Where does all of this leave us as post frame insulation specifiers and building owners?

When I added an exterior elevator shaft to our post frame home two years ago, my insulation choice was closed cell spray foam. I did make an error in that I did not listen to my own inner voice. Our local installer made recommendations for thickness I felt were insufficient, so I had roof and wall sprayed one inch thicker. I should have gone thicker yet as there was plenty of space available to fill. As a result the elevator shaft is cold and drafty into our living space.

Considering closed cell spray foam? Think it may be expensive? Consider its performance will probably be twice as effective as fiberglass and closed cell spray foam suddenly doesn’t seem so costly.


Insulation Between Roof Purlins

From the number of “Ask the Pole Barn Guru Questions” I receive and the new pole buildings I see being constructed, climate control is of very high importance. When I first entered the post frame industry 35 years ago, no one cared about it as virtually all ‘pole barns’ were farm buildings or small private garages. Not the case anymore! Pole Buildings run the gamut from heated shops, airplane hangers with living spaces and custom designed homes or year around lake cabins.

For heating and cooling, it is most efficient to have to control the least amount of space. Reducing the height of the area to be heated, will result in more comfortable temperatures in the area humans typically occupy.

Installing a ceilingThis area can be reduced by finishing off the ceiling (with my personal preference being gypsum wallboard) and blowing in insulation above the ceiling – along with having a properly ventilated attic space. To give a rough idea of the volume of space differentials on a 40 foot wide by 60 foot long by 12 eave height building, having the most typical roof slope (4/12), about 25,000 finished cubic foot of area is to be conditioned with the ceiling, as opposed to nearly 34,000 cubic feet otherwise.

A significant amount of some sort of fuel is going to be used to heat or cool the extra one-third volume of space!

Some people prefer to insulate between the building roof purlins, however this can be fraught with potential challenges if not done properly.

The easiest solution, however possibly not most cost effective, is to utilize spray foam insulation. For most people, this is just not an affordable solution (read more at: https://www.hansenpolebuildings.com/2014/02/insulation-foam-fiberglass/).

Unfaced (typically fiberglass) insulation can be placed between the purlins. The purlin dimensions can be increased to allow for thicker insulation – which will be required (in most cases) if energy code requirements need to be met. By Code, airflow must be provided above this type of insulation. As roof purlins run the longitudinal direction of the building, 2×4 material can be placed flat on top of the purlins, running from eave to ridge. In order to utilize the space created by these 2x4s, the eaves and ridge will need to be ventilated.

A vapor barrier will need to be installed above the air flow area, if the roof is through screwed steel over purlins. An ideal solution would be a reflective radiant barrier, with another flatwise layer of 2x4s placed on top of it (in the same direction as the roof purlins). This creates another dead air space which improves the efficiency of the reflective radiant barrier.

Seriously looking to insulate between roof purlins while conserving energy? Design it right in the beginning!

How Long Will a Pole Barn House Last?

DEAR POLE BARN GURU: How long will a pole barn house last? Should I pour concrete in with the poles? Should I put sleeves on the bottoms of the poles? Question from Karen Sasakwa, OK DEAR KAREN: A properly treated pressure treated timber should outlast the lifetime of any of us here on the planet today. https://www.hansenpolebuildings.com/blog/2012/10/pressure-treated-posts-2/ This means plan on a properly designed pole barn house being around for generations. For the sake of preventing settling, uplift and overturning concrete should be poured around and below the base of the treated columns. https://www.hansenpolebuildings.com/blog/2013/02/concrete-pier/ We can provide plastic sleeves, however the huge majority of new building owners do not use them. https://www.hansenpolebuildings.com/blog/2012/04/plasti-sleeves/

Mike the Pole Barn Guru

DEAR POLE BARN GURU: I have built a 30x40x18. Installed a 6mil vapor barrier on bottom of trusses and a steel ceiling. I blew loose fill r48 in an attic with 2×3 gable vents, ventilated ridge cap “flexovent” and vented soffit.

Now for the walls Tyvec on all exterior walls between girts and exterior panels. I want to wainscot the interior walls to 8′ and finish above w/white poly laminated fiberglass custom manufactured to fill pole voids starting at a nailer girt at the top of the liner wainscot. The grade board is insulated w/2″ pink foam and the same is custom cut and placed on the slab to finish flush with the interior nailer girt to isolate the slab from whatever I insulated the wainscot wall with.

Now my question? I was thinking about filling the cavities in the walls w/cellulose loose fill and possibly tamping it or vibrating it to maybe to achieve some compaction? To slow settling and per industry standards install it correctly. I would use filler strips at top and bottom of all panels to eliminate loss. The fiberglass could always be unattached from the nailer at a later date and more added if settling creates an open space between the glass and the cellulose? My question should I place a vapor barrier between the steel liner panels and keep it continuous with the poly vapor barrier on the glass above it? And will this work? Don’t be afraid of new ideas and just recommend glass behind the wall panels. I don’t like the voids glass always creates in profiled panels with diagonal girts.

Thanks Mark, Ohio City, OH

DEAR MARK: There might very well be an easier way to get maximum R value and fill all of the voids using fiberglass insulation – BIBs. You can read all about it right here: https://www.hansenpolebuildings.com/blog/2011/11/bibs/

My wife and I used it in for our pole barn house and it has performed better than we anticipated for heat/cooling loss.

DEAR POLE BARN GURU: I have an older home with a huge attached garage. I am looking to add a laundry room/bathroom to the garage however wanting it to look original. My home is on a crawl space as well. Could I do a pole barn structure inside the garage? Positive and negatives would be great as well. Cameron in Lima, OH

DEAR CAMERON: Could you? Certainly, however as much as I love pole barn (post frame) construction, building a pole barn structure inside your huge attached garage is probably an overkill. As these interior walls will be non-structural (not load bearing) it would be the most economical to frame 2×4 stud walls with a pressure preservative treated bottom plate.

Mike the Pole Barn Guru

Metal Building Insulation

WMP®-VR Faced Metal Building Insulation

Strange, unusual or uninformed requests are part of the territory when it comes to the world of pole buildings.

Just today we received this statement as part of a request for a quote on a building kit package:

Metal Building Insulation“I would like to line the entire building with MBI (2″ fiberglass with a WVPMR backing Metal Building Insulation)”

My long time loyal readers read of my exploits and experiences with Metal Building Insulation. For the uninitiated, here is a chance for some education (as well as a laugh or two at my expense): https://www.hansenpolebuildings.com/blog/2011/11/metal-building-insulation-in-pole-buildings-part-i/ as well as: https://www.hansenpolebuildings.com/blog/2011/11/metal-building-insulation/

In my humble opinion, the product the client was actually looking for is WMP-VR. WMP® is a registered trademark of Lamtec® Corporation. From their 260,000 square foot facility in Northeastern Pennsylvania, Lamtec has been producing laminated insulation facings for nearly 40 years.

WMP-VR facings has a white polypropylene film, laminated with a flame resistant adhesive to a tri-directional fiberglass/polyester reinforcing and a Kraft paper. With a perm rating of 0.09 this facing will be an excellent vapor retarder (read more about perm ratings here: https://www.hansenpolebuildings.com/blog/2012/11/house-wrap/).

The reinforced facing will aid in preventing rips and tears which, if under or unrepaired, would compromise the ability of the assembly to resist transmission of water vapor.

If the client’s only intent is to control condensation on the inside of steel roofing and siding, then this might be a solution. I would issue the caution of the possibility of noticeable “puckering” of the steel between framing members, due to the thickness of the fiberglass insulation.

More often than not, people have the mistaken idea this two inch thick fiberglass blanket of insulation is going to allow cost effective climate control of the space within the building. Fully expanded, the two inches of fiberglass are going to yield an R value of about 6.4. My opinion is this is better than nothing…..

Well, how thick is the fiberglass when it is crushed between a wood wall girt or roof purlin and the steel siding or roofing? If your answer is – “not very”, you are absolutely correct. And what is the R value of the now very small thickness of fiberglass?

Approaching zero!

Faced metal building insulations do have their places – this just happens to probably not be one!

Insulation: Foam It or Fiberglass It?

I enjoy Hansen Pole Buildings’ Designers who really like to sink their teeth into a subject.

This morning Rick asks me, “Have you ever done a cost comparison on spray foam roof insulation vs the costs of condensation barrier, ceiling load trusses, joists, drywall ceiling and blown in insulation?”

The entire question was brought about, as Rick really gets his clients to think about how they will be using their buildings.

In order to do a comparison, I just plucked from the air a 40’x60’ building, double trusses every 12’ with a 4/12 roof slope and 12” overhangs. Fairly common, pretty standard.

So, what needs to be done in order to spray foam a pole building?

Spray Foam InsulationFor starters, keep in mind (by Code) spray foam insulation cannot be left exposed, it has to be covered with inflammable material – like gypsum wallboard. Gypsum Wallboard is not as flexible as steel, so it has deflection criteria which mean upsizing the roof purlins from 2×6 to 2×8, or changing the column spacing to 10’ on center(o.c.). In the end, when I priced it out the change to 10’ o.c. was less costly, adding only about $900.

In either case, the truss loading will need to be increased to support the extra weight of the system – the top chord loading for spray foam or the bottom chord to create the dead attic space. Statistically – pretty much a wash in costs.

Due to the run of the roof, the spray version is going to take a little more drywall – call it $50

In the northern ½ of the United States, the recommended minimum attic insulation is R-49.

Spray foam is not inexpensive. With 2×6 purlins on edge, the maximum foam insulation thickness is 5-1/2 inches. At R-7 per inch for closed cell foam, will result in an R 38.5. The going rate for spray foam runs from $1 to $1.25 per square foot (sft), per inch of thickness – plus travel and fuel surcharges. To keep it easy, I will use $1 and ignore the rest. Including the run of the roof, roughly 2520 sft at $5.50 per sft is going to cost $13,860.

Total added costs for spray foam = $14,810

How about fiberglass in a dead attic space?

Increased truss load has previously been covered.

Ceiling framing must be added between trusses to support the wallboard – roughly $1200 including all of the Simpson hangers.

A reflective radiant barrier must be placed between the roof purlins and the roof steel, to prevent condensation, which would then rain on the insulation. $650

And the ridge must be vented. Under $200

According to Lowe’s, to get an R49 with fiberglass would require 74 bags of blow-in insulation at $32.75 a bag for just over $2400.

Total costs for fiberglass = $4450.

In summary, spray foam costs would be roughly 333% of the cost of fiberglass, to get to 78% of the R value. The other downside is with spray foam, the area of the trusses now has to be heated (almost 8000 cubic feet of space) before the area below it is going to feel warm!

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.

GreenFiber Insulation

When we were kids, we (and all the extended family) went camping three times every summer – over Memorial, Independence and Labor Day weekends. Dad was always keeping his eyes open for old cabins. He knew many years ago newspapers were used for insulation, and he often scored on interesting tidbits of history in finding portions of 50-70 year old newspapers.

Even our ancestors knew they were losing heat all winter when there was no insulation. Over the past few decades, cooling costs have also increased the need to be able to maintain temperatures inside pole buildings.

Everything seems to be turning green, and manufacturers answer growing demands for quality products which consider both cost and environment.

Any efforts to improve the energy efficiency of a pole building should begin with insulation. Without insulation, heat passes out through the walls and ceiling in winter and in during the summer.

green fiber insulationGenerations ago, old newspapers were used for insulation. Now GreenFiber insulation is made from 85 percent recycled paper fiber. It is effective insulation without the toxins, itch and dust which plague installers of traditional fiberglass products

GreenFiber offers loose-fill insulation for attics or stabilized product for floors and walls. Advantages of natural insulation from GreenFiber include: high-efficiency thermal properties, high R-value, fire resistance, noise reduction, comfortable living and environmental responsibility.

For new construction, install stabilized “blankets” in wall cavities, floors and ceilings. Loose-fill insulation provides the highest quality of insulation by filling all gaps between girts, floor or ceiling joists, purlins or rafters. Of course, insulation may be blown in for new construction as well.

GreenFiber insulation also offers accessories to complete a DIY (Do It Yourself) blow-in installation, including plugs for holes drilled in subsiding or drywall and the actual blower needed to do the work.

GreenFiber insulation is fairly cost competitive to fiberglass insulation, without the downsides. They will even provide information to help determine how much R-value is needed for any particular region or application, as well as tools to figure the amount of product necessary and how to install it.

Federal tax credits may also be available for insulating.

This one is a Thumbs up for me!

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.

Metal Building Insulation in Pole Building Part II

If you didn’t read my yesterday’s blog – you may want to prior to reading today’s, which is the “rest of the story” on metal building insulation, commonly known as “MBI”.

My first experience installing MBI was not a fun one, in any sense of the word “fun”.

What no one warned us about were safety issues during installation. We should have been advised to wear 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. Instead, we spent several days with red eyes, itching skin and hacking up our lungs!

Now fiberglass itself is not some “magic” insulator, it is the dead air trapped in the uncompressed fiberglass which is doing the work. Smash the air out, and you lose R value. As far as an insulator, every time metal building insulation crosses a framing member, it is compressed to nearly nothing and loses its insulation value. People have this mistaken illusion “thicker must be better”.  Not true. Going to thicker products generally does not really add to the overall heat transfer resistance.

In years since, I’ve had clients tell me how a competitor proposed to insulate their new pole building with R-11 (3-1/2” thick) or even R-19 (6” thick) metal building insulation! First, I would hate to even imagine what the steel would look like, after trying to mash insulation this thick down and screw the metal through the insulation to the roof purlins. It would NOT be pretty. (read yesterday’s blog to see why).  Secondly, there is no way the fiberglass is going to come anywhere close to being able to fully expand between the roof purlins. Keep in mind the “product” does indeed have an R-11 capability (in the case of 3-1/2” thickness), when it is laid out in your driveway. As soon as it gets compressed, R values start to shrink. My educated opinion is a 3-1/2” thick product, in service in a pole building, is probably offering a true R value of between 2 and 4 – just slightly above nothing.

We (Hansen Pole Buildings) now partner with several lumber yard chains, providing pole building kit packages to their clients. Two summers ago I was visiting one of the lumber yard locations in Pennsylvania, in order to provide training to their staff. I went out into their warehouse to greet the store manager. Looking up at the roof of this pole building, I saw tattered MBI hanging down from between the roof purlins and hundreds of birds pecking at the fiberglass, to carry it away for nesting! Any hole in the vinyl at all, and a bird in the building, will result in exactly the same scenario being replayed – much to the chagrin of the poor pole building owner who now has no roof insulation, no condensation control vapor barrier under the roof steel of his building, and nothing but a mess.

In my over 30 years of experience, I can truthfully say I’ve never seen Metal Building insulation look to be a perfect “clean and neat” install product under roof steel.  Moreover, far too often I’ve visited older buildings where the inside view of this product “over time was enough to convince me it was not the optimal choice for pole buildings underneath steel.  Back up a few days to read other blogs where I discuss vapor barrier and reflective radiant barriers.  And stay tuned – for more on other insulation products!

Building Insulation: Vapor Barrier

Insulation is one of the topics, once brought into conversation, seems to make most folks’ eyes glaze over.  Many know enough to ask about R Value, and understand “the higher the better”.  Or so they think.  Sometimes you need to stop a minute and go back to the source of what I call “the need”.  This is the way I teach our Building Designers, and clients as well, to think about any feature or addition to their pole building kit when they design their new building.  What are you going to need for your building?  Don’t just throw a bunch of stuff in and on there because it “my neighbor put it on his building”.  What are your needs?  Obviously we all choose features we want on our building, “just because”.  Just because it looks nice, gives the building a classier look, a lower profile, or we think the eagle on the weathervane hovering over the cupola is “pretty cool”.  This is all well and good, but insulation is not one of those “pretty parts” of a building.  Necessary yes, but what type and where do you put it?

When I designed my most recent pole building for my own use, I researched several types of insulation, and ended up using not one or two, but three different types of insulation, and each of them for their own specific purpose in relation to cost.  In other words, “what is the cost value” for each of them?

The types of insulation I looked at ranged from what most folks think of when you say “insulation”: fiberglass insulation, to foam board, spray on foam and B.I.B.’s (Blow in Blanket) along with the reflective type vapor barrier insulation in various configurations and applications.  I ended up putting reflective radiant barrier under my roof steel, wrapped my entire outside of the building in a reflective radiant barrier, put reflective radiant barrier under the heated concrete floor, fiberglass insulation in the interior walls, and then B.I.B.’s in the exterior walls.  Wow, I hear clients saying, “How do you know what to put where?”  Easy – once again it goes back to the “need”.  Over the next couple of days I will cover a few of the insulation choices out there, so get out a sheet of paper, make yourself a grid, and next time you need insulation, ask yourself these easy questions to decide “which insulation you are going to put where” in your new pole building.

First question, what is R value? For those of you who are not familiar with R values, it is simply the measure of resistance to heat flow. R-1 is equal to the resistance of a 1” thickness of wood. Insulation materials have tiny pockets of trapped air. These pockets resist the transfer of heat through material.  The ability of insulation to slow the transfer of heat is measured in R-values.  The higher the R-value, the better insulation’s ability to resist the flow of heat through it. Before you consider these products, read the test reports carefully.  In order to achieve the full promised values, the products must be installed in the center of an appropriate dead air space.

Second question, what are you going to be using your building for?  This will help you to determine what type of insulation you are going to need.  Of course, your “need” for insulation also depends on where you live.  If you are in Minnesota where I have my newest building, and want to change the oil in your car in January, putting reflective radiant barrier in the roof and even on the walls is probably not going to keep me warm.  No heating system is going to keep up with the heat pumping out of my building!

And, if you live in Knoxville, Tennessee and are OK working in your shop with coveralls on a few hours a week, your insulation answer will be greatly different than if you want to sit in your new shop in your shirtsleeves with your buddies watching the Super Bowl come January!

So your first project is this: take a sheet of paper and write down all the things you want to “do” within the confines your new building, including keeping pets, horses, or other animals at the right temperature.  Also make a list of other reasons we put insulation in spaces – noise for one.  Do you need good sound abatement for the “practice garage” for your son’s rock and roll band?  Is the loft bedroom right above where you work on motors or have a workshop with noisy machinery?

Once you decide on what your needs are for insulation, you can just match it to the Insulation Grid we’ll be making over the next several days.  I’ll be back tomorrow to start with the simplest of all insulation: reflective radiant barrier which includes a vapor barrier.  Winter is coming, so stay warm!