"Building assesmblies need to be able to dry in at least 1 direction. Rigid insualtion on top will limit the drying to the outside so you should allow it to dry inward. I would agree with David and use cellulose. I would not use poly on the…"
"I would consider using cellulose insulation blown in between the rafters, rather than spray foam against the skip sheathing. Foam on both sides is risky, in my opinion, and will make any future repairs to the roof structure a real challenge. Since…"
We are going to be rehabbing a home in CT in which the third floor is part of the living space. We want to get the insulation level up by using either nailbase or 2 layers of 2" tuff-r with staggered seams on top of the deck. We are going to use close cell spray foam with polyisocyanurate insulation to…See More