Is former ventilation space a problem with exterior rigid foam.
Hello, thanks for all the info here on GBA!
I have a cape cod and I keep on coming back to the idea of exterior rigid foam to insulate my roof with shallow rafters. I was talking with a contractor and he said rigid foam above roof sheathing with the ventilation gap beneath wouldn’t be good for moisture. Is this considered true?
I thought it didn’t matter because the new roof assembly would either be not vented because of a sealed roof envelope and the option to vent the new roof decking if need be.
Thanks for the help,
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