What type of interior insulation with 1″ exterior rigid foam?
I had a strong hand in the design of my new home. However, I was a newbie when detailing the exterior wall details and we only put on 1″ of exterior rigid foam. I now wish we would have done 2″, but it’s too late to change. We are currently planning on installing closed cell foam as interior insulation, but I just heard Martin speak on the Fine Homebuilding podcast and he says that rigid foam on the exterior and closed cell foam on the interior is a dumb idea. We live on Cape Cod, have 2×6 exterior walls with plywood sheathing, a liquid WRB, the 1″ XPS foam, a rainscreen and cedar shingles. Would you recommend cellulose as the interior insulation to use in this situation?
Thank you for any guidance you can provide!
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