Certainteed Membrain: Reviews and opinions, please
New build, climate zone 6a. High altitude snow country. My insulation contractor is really pushing me away from doing a ccSPF on the underside of my sheathing and very strongly suggesting I use this certainteed membrain. Here are my options for roof design for my un-vented 2.5/12 pitch cathedral ceiling shed roof:
A) 14″ TJI rafters with 5.5″ of ccSPF and 8.5″ of netted and blown in insulation
B) 16″ TJI rafters with 16″ of netted and blown insulation but using Certainteed Membrain – a nylon smart vapor retarder.
The Membrain is stapled to the underside of the TJI’s and has a 6″ overlap between sheets. It doesn’t sound like the seams of the membrain (not membrane :)) are taped or sealed.
What experience do people have with this product?
Is method B a good design? It is more than $10,000 cheaper than option A.
My walls are exterior foam and netted and blown fiberglass stud cavity with a latex paint vapor retarder. How do I connect this membrain to my latex paint so I have one continuous vapor retarding control layer?
I really appreciate any insight into this product.