Hot Diggity Sog
Well-Known Member
I think you want to do black plastic on the exterior. The foam board will prevent moisture to pass thru it (providing it is closed cell XPS). I suggest the Dow XPS 1 inch board.
It will much easier to create an air tight seal with the foam than with the plastic (I would think). Neither will allow moisture to pass so unless the interior layer is not tight you shouldn't have an issue. You want to use PL300 adhesive and low expansion closed cell spray foam for your 2 gluing/sealing products.
It will much easier to create an air tight seal with the foam than with the plastic (I would think). Neither will allow moisture to pass so unless the interior layer is not tight you shouldn't have an issue. You want to use PL300 adhesive and low expansion closed cell spray foam for your 2 gluing/sealing products.