Adding Rigid Foam Insulation on Top of Existing Vapor Barrier
Currently sitting near the SF Bay in climate zone 3. I have a ventilated crawlspace that someone went to the trouble of sealing (up to the rim joist), but didn’t insulate. I’d like to seal and condition the whole thing but all the details I’ve looked at show the insulation behind the poly barrier (against the wall). Am I doomed to pulling the barrier off the walls (with all the attached adhesive, fasteners, etc) and attempting to sandwich foam board behind it? Or, is there some way to layer it on top that won’t create a moisture nightmare?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part