Open cell spray foam under roof deck
A couple years ago we converted our vented attic to an unvented/conditioned attic with open cell spray foam applied under the plywood roof deck. We even installed an HVAC vent in the attic to keep the RH in the attic similar to the rest of the house. So far everything seems fine but I’ve recently read about issues with open cell under roof decks, including one article on this website. I live in climate zone 4, asphalt roof over plywood deck. Should I be concerned about having a wet roof deck? And what can be done to help if so – possibly over roofing with 4 or so inches of rigid insulation? Which I’ve thought about doing anyway to increase the R value and eliminate thermal bridging from the rafters. Thanks.
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