Quote Originally Posted by Dana View Post
Then, be sure to use high-permeability paints on the gypsum or you'll be looking at mold on the furring strips/studs in only a few years- it has to be able to dry toward the interior. Don't use vinyl or foil wallpapers- same story, only worse. There's a bunch of research & data on this- you can read up on it here:

I'm with you up until the paint . Most paints do not have a low enough perm rating for this to be a concern, unless you buy one that specfically is designated as such e.g, vapor retarding paint.

I do like you point of foaming any seams after installing the XPS....This is often over looked especially when the sheet meets the floor