Should a Vapor Barrier be installed over Exterior Grade Plywood?
I have a 40 year old cottage in the Kawarthas. It has exterior grade Plywood. The walls are insulated with traditional Fiberglass Pink. I will be putting solid 3/4" wood siding over top of the exterior walls. I plan on strapping the cottage with 1" x 2" and filling the gaps with 1" of Rigid Foam insulation. In the future I may add A/C to the cottage. Do you believe a Vapor Barrier to be necessary? Thank-you Michael