Hey, need some help on how to insulate my roof. This is a pole barn building that originally had a steel roof and now has sheathing and shingles. The walls just have 1" foam board then the steel but nothing for the ceiling roof. In the winter when out there I lose all my heat as soon as I turn off the heater, so is it worth nailing foam board to the bottom of the purlins or r13 rolls then foam board? Or will that cause any problems with ventilation and moisture on the bottom of the osb? I'm trying to insulate the roof line and not add a ceiling to keep height in the shop.
