Any problem using unfaced insulation and covering it with plastic?
Roy writes from Beckley, West Virginia: “Are there any problems with using an unfaced insulation in a 2×6 wall and then sealing it with a sheet of plastic? All walls are above grade. I always thought it was easier to do this way. Any problems or concerns I should be aware of? What insulation would you recommend r-21?” Answer: Our Kraft-faced insulation would be adequate as a residential vapor retarder. However, it is common to use unfaced insulation and a 4-6 mil poly over it in above-grade applications.
