Vapor permeable rigid insulation boards???
Is there such a thing? I’m assuming all rigid foam boards are not vapor permeable?
I have a home addition with a flat EPDM roof. I missed adding insulation underneath the EPDM since it’s technically not required in climate zone 2. Now I wish I had.
so im thinking of open cell spray foam in between the 2×6 roof rafters. Then adding some other piece of sheet type continuous insulation that can be screwed or nailed to the bottom of the rafters before my Sheetrock goes up.
id like to add R-value and eliminate thermal bridging which is probably quite significant since the rafters are 12”oc. Since I already have a vapor barrier on the outside (epdm) I assume I would need something permeable on the inside so I don’t create a double vapor barrier?
anybody have any ideas or tips on what could be used?
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