How to insulate a hot roof from the inside
I’ve talked to roofers. None of them knows anyone willing to put the foam board insulation on the roof decking under the shingles.
I need to replace moldy drywall inside a closet that was put up to covering failing plaster. After 122 years, I think it’s entitled to fail, so no complaint there.
If I attached the closed-cell foam board insulation inside, where does the vapor barrier go? Against the lath before I put up the foam board? Or over the foam board before I put up drywall?
From reading GBA, I take it the single most important detail is fully sealing the vapor barrier. Will do, just want to know where.