Exterior rigid foam insulation under siding
Crown2001
| Posted in Energy, Heating & Insulation on
I live in Massachusetts(zone 5). My house siding is the original wooden shingles covered with vinyl siding. The walls are drywall, poly sheeting, 2×4 studs with fiberglass and plywood sheathing. I want to remove the old wooden shingles and vinyl siding and replace with 1” rigid foam on the exterior covered with house wrap and vinyl siding. New constructions windows will be installed spaced out 1” to sit on the rigid foam. Will there be moisture issues since neither the poly sheeting on the inside or rigid foam on the outside will allow moisture to escape the wall cavities?
Replies
Place the WRB over the sheathing, then install your 1" rigid on top of it. This way is typical. I would recommend installing a WRB with a drainage plane built into it: Rainslicker by B.O.
This allows any moisture that gets past the vinyl siding and insulation to drain freely down and out. Double check with the siding manufacturer regarding attachment over 1" of rigid insulation. They may require furring for attachment.