Pole barn roof insulation

[rick1ryan]

I have a 40'X90' pole barn structure which already has the plastic insulation installed under the metal. The barn is completely enclosed in T-111 and insulated all around with R-19. I'm thinking about insulating the roof further and have looked at blown insulation (expensive-$7k+) and now looking at Poly ISO ($2.5k) The ISO would have to be cut into 2' strips then glued to the bubble insulation. Wondering if anyone here had done this or had any info in regards. Thanks in advance.

 

[GSVette]

I didn’t go the poly iso route- did consider it. I have R19 batt installed between purlins and then covered with the white plastic paper( don’t recall what it is actually called).

 

[WranglerX]

Have you consider labor cost (time) between spray foam and sheet foam.... If you go with sheet foam be sure you have excellent glue .... Gluing sheets to your "bubble" (need better description) may not actually be doable....

 

[tguy]

Before you glue anything to the bubble insulation, make sure it was properly installed. The bubble wrap in my building was installed directly touching the metal roofing, and 10 years later it has deteriorated and is falling down in pieces!

 

[mx842]

Before you glue anything to the bubble insulation, make sure it was properly installed. The bubble wrap in my building was installed directly touching the metal roofing, and 10 years later it has deteriorated and is falling down in pieces!

Just my thoughts.....Most Any insulation needs an air gap between what you are insulating and the insulation itself. Moisture is your enemy of course the foam could probably hold up to the moisture form any condensation that may form but I don't know what's going to happen to any wood that might be in the area. Plus like some others have stated I don't know how much luck you are going to have gluing that foam to the bubble wrap. You could put ferring strips between the two and glue and nail to them. Then you would prolly need to tape the seams unless the pieces fit really tight.

 

[DanMc77]

Insulation in a large building. How do you keep the mice out? What a menace.

 

[EddieWalker]

I have never done this, so I'm not speaking from personal experience. I worked on a house once that the 2 inch poly attached to the bottom of their rafters with long screws and it was very well insulated. Each sheet was installed kind of like you would install plywood or osb, except it was on the underside of the roof.

I would not rely on glue. If the bubble insulation fails, then it will all fail.

If you want to cut it into 2 foot strips, hold it in place with strapping of some kind. Probably 1x2's

You can also buy thin metal rods that are designed to hold fiberglass batt insulation between floor joists that should work. Or you could just install fiberglass batts instead of the foam sheets and hold it in place with staples and the metal rods.

 

[TractorGuy]

I'm not sure if or how it relates but I wrapped some cylinder heads up in bubble wrap once and put them in cardboard boxes. When they sold the buyer picked them up. When I unwrapped them they were dripping wet and the cams were rusting. They had been wrapped for about 2 months.

I will NEVER wrap metal in bubble wrap again.