Pole Barn Insulation

[ArtisanFarms]

I know, not a new topic, but sometimes people have new opinions/experiences.

I’m located in Central NY and will be building a 30x50x12 pole barn shop this year and am trying to make a decision on insulation.

I’ve been quoted R19 fiberglass batts in the walls and R42 chopped fiberglass in the ceiling or R21 foam in the walls with R42 chopped fiberglass in the ceiling. The spray foam would be $1,450 more than fiberglass. I’m planning to heat with minisplits and will keep the shop between 50 & 65 depending upon how it is being used.

Both options will have tyvek underneath the steel siding and liner panels for the interior walls and ceiling with rat guard at the base and appropriate trim in the corners and between the wall and ceiling to minimize any gaps and reduce potential airflow. The exterior wall will also have rat guard at the base and vented soffits and baffles in the eaves to facilitate air flow over the chopped fiberglass ceiling insulation to the vented ridge. I’m planning to surface mount the electrical in EMT to minimize penetrations.

My contractor is recommending the fiberglass option as being more cost effective over the project life (20 years). I tend to agree, but am looking for other’s opinions and experiences. Cost is definitely a driver here, but so is comfort. This will be my last shop (I’m 58) and I’d like to build something that will be good to work in for as long as I’m able to work in a shop.

 

[ndfastang]

I'm in Wyoming with a 30x48x11 so I'm close to yours in size. I did my walls with R19 and am doing my ceiling in R38-42 as well. I am recessing my electrical into the wall though and am dealing around the boxes. It gets sips windy here and typically teens for low in the winter. I would have done closed cell spray but we get hail here allot!!! I will surely replace the outer paneling at least twice in the 10 to 12 years i will live here. The spray in doesn't work well with replacing panels. If you don't have that issue, go for the spray and some other supplemental insulation. I think your venting sounds solid. I have a ridge vent up to that I stuffed rain gutter breathable foam in. We have Miller moth problems here in spring..... badly!. I'm going to put a single Hanke vent in the attic on the non windy end. I think you have a sound plan. I'm going with a 36,000btu mini split myself with the same temp range in mind. I think you'll do fine. I wish I had the extra foot of height. It would make a world of difference with my truck on the lift.

 

[dcg9381]

I did foam, it's more expensive, but just dead easy and gets in all the nooks and crannies, better for sealing the building. I'd consider a combo too - IE, a foamed roof deck and then bat the walls, which would give you a good combination of economy and installation ease.

I have a 40x60x16, my insulation is "moderate" (maybe R-15). It doesn't get cold here much, but when it does get down to freezing, mini-split performance is impacted (fewer BTUs) and note that the Daikin units that I have also have a defrost cycle... I use 2 x 24k BTU units, cools well into the 100 degree mark, but below freezing, I'm probably not going to heat past the high 60s..

 

[karoc]

I did foam, it's more expensive, but just dead easy and gets in all the nooks and crannies, better for sealing the building. I'd consider a combo too - IE, a foamed roof deck and then bat the walls, which would give you a good combination of economy and installation ease.

I have a 40x60x16, my insulation is "moderate" (maybe R-15). It doesn't get cold here much, but when it does get down to freezing, mini-split performance is impacted (fewer BTUs) and note that the Daikin units that I have also have a defrost cycle... I use 2 x 24k BTU units, cools well into the 100 degree mark, but below freezing, I'm probably not going to heat past the high 60s..

Have you had any problems with the metal popping, how do you like the spray foam. I have read so many good things about it.

 

[Dragfluid]

42x72x14. Dense packed cellulose in the walls with 1" polyiso between that and the 1/2 drywall. House wrap underneath the outside steel. Approx R36. We blew 20" in the ceiling and expect it to settle 2-3". I heat it with an 85k BTU hanging propane furnace. I have 3) 52" ceiling fans. It's very warm and comfortable winter and summer. I cool it with a tiny 5k BTU window unit. You can see pics in my build thread for more details.

 

[jvitez]

No offense intended with my comments, but fibreglass is actually the worst type of insulation available now, maybe with the exception of bubble wrap. Critters will live in it, if it gets wet it collapses down the stud bay, and it supports mold. Only good thing is it's relatively cheap.

Blown in attic fibreglass is touted as keeping it's R-value by not settling, but because it stays fluffy it supports convective heat loss within the insulation itself, more so the higher the temperature difference between the ceiling temp and the attic temp.

Blown in cellulose ceiling insulation is far better. The top couple of inches does settle a bit, but gravity and moisture cause a crust to form on top sealing the rest of the insulation from convection currents, so it retains it's R-value at very cold temps.

Mineral wool insulation is far better wall insulation than fibreglass. Water pours right off the mineral wool, critters don't like living in it, and it doesn't burn well in a fire.

Closed cell spray foam is the best, both in R-value per inch (~7), and in air sealing. But it is the most expensive.

If it was my pole barn I'd use Rockwool mineral insulation in the walls, and blown in cellulose in the ceiling.

 

[dcg9381]

Have you had any problems with the metal popping, how do you like the spray foam. I have read so many good things about it.

I haven't had any issues with metal popping (not sure what that means). Metal building suppliers like to steer you away from this stuff and may say "voids warranty" - my guess is because they want to sell you their own insulation solution (which isn't nearly as good).

I'm aware of a bunch of metal buildings (hangers) that have had foam for more than 10 years with no problems.

I really like foam - I've done 3 structures with it. I won't use a different type of insulation due to the "closed envelope" that it provides over any form of bat or cellulose. It's down side is that it's expensive (comparatively) and needs to be installed by a contractor that knows what he's doing.