Roof deck: open-cell or closed-cell foam?
I’ve been going back and forth with my spray foam company. My foamer originally pushed open cell but is now telling me closed cell, which was my decision, is the best application for my situation. He originally said that open cell was overall a better value.
I have 2 by 9’s at the roof. So I’m limited on space for spraying.
My final plan was to put r21 of closed cell spray in with r21 of regular batts underneathe it to achieve r40+.
I live in NY.
After talking to an energy guy, a pro, he said open cell 100%. It lets the water come through so you know if there’s a leak. But my sprayer said so what? He said the open cell foam would absorb 20lbs of water before that happened and if you had to fix the area, you would have to remove the wet open cell foam.
So. Anyone have some guidance on this?
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