CooperFarm
Active member
Good morning GJ folks- Construction is complete on my new 26x38x12 pole building, just waiting on concrete. In the meantime I'm seeking suggestions on insulating the ceiling/roof. I intend to use 3"x4'x8' polyiso boards that I picked up off CL, but I'm a little uncertain as to their exact placement. Should I fit them as close to the metal roofing as possible (ie: secured directly to the purlins) or drop them down flush with the bottom edge of the truss top chords, thus leaving a 4" air gap between the foam and the metal roofing? I've got 12 inch overhang (eave and gable) and vented soffits and ridge. Would I be defeating the purpose of the vents by effectively isolating them behind the foam? BTW, I'm located in NJ, where it has already been over 90º and humid. Forgive my ignorance, I'm new to this realm. Any suggestions would be greatly appreciated! 