Is it possible to reach a dew point inside of a wall cavity that is insulated with 3.5 inches of closed cell spray foam?
My wall assembly consists of fiber cement siding, Tyvek Drain Wrap, 1″ XPS Foam Board, OSB sheeting, 3.5 inches of closed cell spray foam inside of a 2 X 6 stud wall, drywall, latex paint. I have complete the Advanced Green Building Science course and learned how to calculate dew points, but they don’t take in account the permeability of the cavity insulation . I am not finding any information and/or specifics for closed cell spray foam from this site or other creditable sites. My spray foam contractor is saying that moisture can not move trough the spray foam or through the XPS so moisture should never get to the OSB and create a mold problem.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part