I have read that with me putting two layers of 1 1/2 inch foil-faced rigid foam with staggered joints on the outside walls, I don’t put a vapor barrier on the inside.
Now on my low-slope roof, I have 2×12 rafters. Starting at the top, I have:
15 lb. felt paper-
ice shield over the full roof-
1/2 inch plywood sheathing-
1 5/8 inch air space to vent-
1 inch foil-faced rigid foam, caulked at the edges-
1 1/2 inch foil-faced rigid foam, caulked, with staggered joints-
2 inch foil-faced rigid foam, caulked, with staggered joints-
5 1/2 inch Roxul insulation.
Do I put the vapor barrier on the inside?
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