Insulation

[MSU 21]

About to get started on a pole barn. The builder uses foil backed bubble insulation. Would it cause any issues putting roll insulation between it and the interior wall? What would be the best option for putting insulation in the roof. Using metal trusses.

 

[gstrom99]

I've heard/read that the bubble wrap insulation is pretty useless and can trap moisture, on the roof anyway.

 

[RustyA]

We used the foil roll insulation between the metal roofing and the purlins in an uninsulated pole building. It was designed to help control condensation on steel roof in cold climates. I've been in bare roof pole barns where it actually rains inside when the roof sweats on cool humid days from melting frost.
Ours never sweated except in the lean to that the roll insulation was not installed.

 

[m1garand762]

Before you commit to a pole barn do some research on ICF we are building our house cheaper that way and it’s actually a lot better than using wood

 

[Fallon]

Before you commit to a pole barn do some research on ICF we are building our house cheaper that way and it’s actually a lot better than using wood

Last o saw a few years ago ICF was 15-20% more than stick built. Better insulation, air tight construction, massively reduced noise, "bullet proof" & a host of other benefits though. Would likely be what I eyed up if we ever end up building a house (or new shop).

 

[m1garand762]

Last o saw a few years ago ICF was 15-20% more than stick built. Better insulation, air tight construction, massively reduced noise, "bullet proof" & a host of other benefits though. Would likely be what I eyed up if we ever end up building a house (or new shop).

The quotes we got for our house were 6%less than stick built, but I am building it myself it’s not hard and you can take the class for the license online in a few hours. Not naming brands but we went with the only brand of block that is green in color

 

[Fallon]

The quotes we got for our house were 6%less than stick built, but I am building it myself it’s not hard and you can take the class for the license online in a few hours. Not naming brands but we went with the only brand of block that is green in color

Could very easily be these days. It's probably pushing decade at this point since I looked into it. We ended up buying rather than building, so I stopped looking into it.

 

[dieselscout80]

Our new garage is being built and we had them instal the bubble insulation directly behind the sheet metal. The manufacturer website says it’s up to R6.

When it’s done I want to add more insulation to both the ceiling and walls.

The structural steel tubing is 2.5” square on five foot centers.

Options
1. adding a second layer of the bubble insulation but stick it to the inside of the steel tubing creating a 2.5” dead air space between the layers of bubble insulation. Would this give me a higher R value than just the two layers of bubble insulation?

2. add 2” foam boards between the posts without compressing the bubble insulation. and use spray foam to secure/ seal them. What R value should I get?

3. for the ceiling I may blow in say a foot of fiberglass insulation and the walls could w done with option one our two.

 

[drumminj]

I've seen many articles that comment on how the bubble insulation r-value isn't accurate. It's really only R-1.5 or so. It works well as the 'outer' layer for a pole barn though as it won't be damaged by water and doesn't support birds or mice nesting in it like fiberglass batts.

Personally, I'd go with the rigid foam board as your second layer. XPS, EPS, and polyiso have different r-values per inch and different characteristics -- if I remember correctly, XPS insulative value degrades over time and polyiso's insulative value declines as temperature drops, but EPS has the lowest R value per inch. I'd verify that, though, as my memory may have jumbled up those details.

Did you exclude batts in the walls for some reason?

 

[ROUSTABOUT]

Our new garage is being built and we had them instal the bubble insulation directly behind the sheet metal. The manufacturer website says it’s up to R6.

When it’s done I want to add more insulation to both the ceiling and walls.

The structural steel tubing is 2.5” square on five foot centers.

Options
1. adding a second layer of the bubble insulation but stick it to the inside of the steel tubing creating a 2.5” dead air space between the layers of bubble insulation. Would this give me a higher R value than just the two layers of bubble insulation?

2. add 2” foam boards between the posts without compressing the bubble insulation. and use spray foam to secure/ seal them. What R value should I get?

3. for the ceiling I may blow in say a foot of fiberglass insulation and the walls could w done with option one our two.

You are fine as long as two vapor barriers aren't against each other. I've built things with extra insulation behind the metal building insulation. Have each vapor barrier facing toward inside building. Put double batts above ceiling tiles below vinyl insulation. Did walls too. Over 20 years ago and no problems. You can get 9" batts for the wall. Of course you can get less, but batts are the way to go. I have built many projects as a contractor.

 

[LouNY]

Everyone has their own thoughts mine are spray foam is the best, followed by foam board well fitted and sealed, then lastly fiberglas batting.

 

[ROUSTABOUT]

Last o saw a few years ago ICF was 15-20% more than stick built. Better insulation, air tight construction, massively reduced noise, "bullet proof" & a host of other benefits though. Would likely be what I eyed up if we ever end up building a house (or new shop).

I don't think ICF is any more expensive. Built several structures with them. That 60 dollar light bill compared to a 300 dollar light bill is where they outshine the rest. Not to mention tornado and hurricane resistance. One 16" by 48" block is the same as six cinder blocks. I been laying those instead of cinders. Used them as forms many times. Cut off inside and used like header blocks on a slab. I also love FASTFOOT, a very useful product. But, what do I know.

 

[ROUSTABOUT]

Everyone has their own thoughts mine are spray foam is the best, followed by foam board well fitted and sealed, then lastly fiberglas batting.

I've seen just as much spray foam taken out as I have seen put in.

 

[ROUSTABOUT]

I've heard/read that the bubble wrap insulation is pretty useless and can trap moisture, on the roof anyway.

Never had a problem with it. I put it on all the time and have for a long time. That's a fine example of hear say.

 

[ROUSTABOUT]

Before you commit to a pole barn do some research on ICF we are building our house cheaper that way and it’s actually a lot better than using wood

I can handle any ICF questions. I've built big ole monsters with ICF. Three story 10,000 sq ft was my biggest. Ten foot down was my deepest. Add in radiant floor heat and a colored slab with wet set blocks and I pulled it off perfectly, down in that 10' hole, 5,000 sq ft slab. No pump truck, poured out of a truck. Those are the days you remember.

 

[LouNY]

I've seen just as much spray foam taken out as I have seen put in.

I have not.

 

[ROUSTABOUT]

I have not.

Twice I have personally seen it taken out from under a house and then replace all the floor joists. Caused them to dry rot. Ive seen it have to come down from metal buildings too. Caused too much rust, held moisture.

 

[Jimmy Joe]

I always read the vapor barrier should be on the warm side of the wall but that seems to be a grey area as when people reside their homes they add foam insulation to the exterior seems not to cause a problem.

 

[EddieWalker]

I know of a house that was for sale for $800,000 in my area that used open cell spray foam on the roof that hasn't been able to sell because the foam is holding so much moisture that it's rotting out the roof. The house is only a couple years old, but the shingles look like they are at the end of their life. It's really bad.

I've seen a few metal buildings with open cell foam insulation that are visibly rusting on the outside. They need to have the foam removed, but haven't done so yet and they are trying to find an option to the moisture issues caused by the foam.

I've never seen an issue with closed cell foam on a house or metal building.

I personally prefer fiberglass insulation over foam because of the price, but I'll be using closed cell foam on the ceiling of my great room when I'm ready to insulate it. My reasoning for spending the extra money is that it's the only way I'll be able to get the R Value I want with a limited amount of space. The isn't going to be an attic, just the thickness of my trusses and purlins for a total of 7 inches.

If I was going to insulate a metal building, and I had a limited budget, I would fiberglass the walls, and try to put a ceiling on it so I could blow in fiberglass in an attic. Using metal R panels for a ceiling allows you to go 4 feet for your joists without any issues. If that wasn't possible, then closed cell foam as thick as you can afford would be the only other good option. I don't see any advantage in cost by buying sheets of foam and trying to fit them into place. You still need to buy cans of foam to fill the gaps and tape all the seams. The YouTube versions that I've seen of this being done convinced me that it's not a good option.

 

[Mtsoxfan]

I've seen just as much spray foam taken out as I have seen put in.

Just curious, why was faom taken out so often?

I used a foil backed bubble wrap, 1/4" thick to insulate my garage doors. All the companies boasted R8, doubling up only brings to R10.