Pole barn wall insulation FOAM or FOAM??

[midwest farms]

Hi, I am new to the forum but should have come here several months ago. I have been building a 30x54 x 18 pole barn in my spare time doing most of the work by myself but have had a few willing hands to help with the concrete finishing, heavy framing trusses and perlins and hanging the longer sheets (end walls and roof). Thankfully the project is coming to an end. As with all projects the budget has come to an end as well! I plan to insulate and sheet the inside of the barn (foam on walls and sheeting and loose cellulose on top of the ceiling).

Here's where I could use some insight:

I priced having the walls foamed with close cell. Quotes were 3-4k for 1.5" foam. With an R value somewhere around 9-10. Instead, I was considering hanging 4x 8 sheets of 2" polysio foam board. I can buy factory seconds locally and could sheet the interior walls for about $900. R value is around 12. I was considering hanging this with a 1" gap on all edges and then using DIY closed cell foam kit to fill and seal all the voids. The DIY kits cover about 600 square foot and can be bought for about $650. That would save $1500 to $2000 and basically gain the same if not better R value. I know this won't be "pretty" but the walls will be covered. This savings will basically pay for much of the interior liner steel!

Advantages as I see them:
1. Gain a sealed envelope and minimize any air infiltration like closed cell spray foam.
2. Save significant $'s which would be put back into the interior liner steel.
3. Slightly higher R value (negligible really)

A couple things I was concerned about:

1. Will this cause sweating in the dead air space between the steel and the rigid foam? (primary concern)
2. Will the closed cell foam adhere to polysio foam? If it will stick to painted steel I don't know why it wouldn't stick to rigid foam.
3. Although water resistant it can absorb water. This type of panel is also used for roof underlayment and is foil backed on both sides so I am less concerned.


Let me know your thoughts or if you have ever seen something similar to this attempted before. I'm open to suggestions!

Thanks in advance!

 

[AlZee]

I just went the sprayed foam route this summer in a pole barn about the same size as yours. I did the walls and roof for a totally sealed building. Bit the bullet and paid the bucks but would do it again. Very happy with the building.

Biggest advantage (besides the insulation factor) in a metal pole barn is increased structural rigidity. Winds in Wyoming really whip around and and now I barely notice them. Also, the amount of dust penetrating the building was cut down dramatically.

This may be an advantage you haven't considered for spray foam. It was a major one for me. However, I would say that if you don't spray your ceiling then you'll lose a lot of the advantages of the spray if all other factors remain the same. IMHO it's an all or nothing deal for spray.

Several folks on the board went with foam boards and have great success. Do a search and some of your issues are addressed.

 

[midwest farms]

The rigidity is a great point. I was trying to get the best of both worlds gaining a totally sealed wall while avoiding the full cost of the spray foam for the entire project. I am wanting to finish the barn with a metal ceiling fastened to the bottom cord of the trusses so was planning to use blown in. I guess I could have that foamed as well and add blow in on top if I needed more R value.

 

[midwest farms]

This brings up a second point:

If I were to foam the entire building including the underside of the roof, would this cause a potential sweating problem in the attic if I still installed a steel ceiling on the bottom side of the truss cords?

 

[AlZee]

That's a good question because that's my plan for the future. No insulation, just metal or sheet rock. The installers told me that I may see some sweating inside, but that a cheap fan to move the air around is the solution. I'll get to see soon at this is the first winter for the insulation.

 

[PeterT]

Spray in foam is nice, but it sure is expensive. I did the do it yourself from Tiger spray foam and it was about $600 for 50 cubic feet. I ordered two kits, and had 4 cannisters (about the size of bbq propane tank) delivered.
It went on pretty easy, not too big of a mess.

I found out later, I could of had the pros come in and do it for about the same price.

 

[csargents1546]

As long as you provide enought air movement above you ceiling, sweating should be minimal.

 

[zeebad1]

I hired a company from central Illinois to cover the walls & roof of my building, and after 2 years, am very thankful for that decision.

I know that it's very costly, but it's just like field drainage tile. It's going to cost you, whether you have it, or not.

I've been in very nice, well insulated buildings, still to hear or feel the wind blowing through the walls at times. I have none of that, as my building is sealed up tight.

No fans, and no sweating in mine.

 

[AlZee]

Amen to hiring the pros. I priced it out and the DIY was about the same price. Pros knocked it out in two days, cleaned up their mess and swept out the pole-barn to boot.