Roof Venting
chrislene
| Posted in General Questions on
Is a roof that has a plywood deck with 3/4 furring strips on it and then another plywood layer on top with asphalt shingles considered a vented roof? The vent channels are between the two roof decks not beneath the bottom deck as one might traditional find them. Wondering if it OK to use open cell spray foam in this type of vented roof assembly. Zone 6. Thanks
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That is technically not a vented roof, the vent channel must be 1.5” and is supposed to be under structural roof deck and above the permeable insulation. Someone who uses open cell spray foam could chime in about it’s code compliance in this situation, though I would personally not use it, as there is the risk in cold climates for it to hold moisture. I would not use open cell at all, but definitely not in zone 6.