I recently built a barn, a wood structure with R Panel siding, with a room up top that I’d like to control the temperature in. I’ve been told every possible way to insulate, from spray foam to a spray on radiant barrier paint with just regular roll-in insulation. Any thoughts? (the metal is attached to 2×4 lathes with no decking anywhere and studs/rafters are on 16″ centers)
Thanks for your input,
Tom: Yeah, when you have a metal building and you’re going to condition the inside, which would be this room, I assume he’s going to have air conditioning and heating. The metal can’t stay exposed on the inside, it’ll sweat, it’ll get cold, it’ll get hot, it’ll reach dew point. So any time you have a metal building of any kind, and that’s what the R-panels are, you have to put insulation up directly to the metal so the air won’t touch it. That way it won’t sweat. It’s kind of like a koozie on a beer can, it’s just the best way to explain it.
So in this case whether you do … and I’m not a big fan of spray on foam, but on metal this would be an application it would work or you can get the fiberglass, but it has to be put up pretty tight against it. That’s an old way of insulating metal buildings. They actually have some vinyl-coated insulation that goes for metal buildings that gets put up tight against it so it won’t sweat even if it’s not air conditioned in warehouses and stuff, but you have to insulate up against it. The radiant barrier is not going to be a factor here because if you spray it on the metal you still have to insulate against it then the radiant barrier doesn’t work.
Charlie: So in this case, this is one place where you say the spray would work?
Tom: Spray would work on a metal.