Is it OK to put a plastic vapor retarder over faced insulation?
Thomas writes from Wasilla, Alaska: “I am building a garage here in Alaska- south central area so weather isn’t usually extreme. Is it ok to use faced insulation and put a plastic vapor barrier over the faced insulation?” Answer: If you are installing Kraft-faced insulation, a poly vapor barrier is typically not necessary. The Kraft-facing is a sufficient vapor-retarder. The use of poly over Kraft is, however, acceptable. There should be no moisture problem as long as the poly and Kraft are adjacent. Check with your local building code to be sure there are no special vapor retarder requirements in your area.
