Discussion Starter · #1 ·
To get more R value in my attic conversion project I am adding 1" foam board after putting R-21 into my 2X6 rafters. I am using unfaced batts and was planning on using foam board with foil backing. Question, most foam boards come with backing on both sides. Would this constitute a double moisture barrier? I didn't think so, but want to make sure before putting up. Sheetrock will be put up after foam board.