A layer of sheathing over new exterior foam insulation flattens the walls and simplifies flashing and siding installation.
After cleaning off the stem walls and reapplying asphalt dampproofing, workers installed a double layer of 1 1/2-inch-thick XPS foam, staggering and foaming the joints to minimize air intrusion.
A peel-and-stick ICF waterproofing membrane protects the new foam from moisture below grade, while a stucco coating protects the above-grade portion from UV damage.
After removing the old windows and installing plywood window bucks, workers wrapped the walls with 4x8 panels of 4-inch-thick polyisocyanurate foam.
The panels were glued to the vertical cedar siding.
Plywood cleats secured with long screws were used to temporarily hold them in place until the glue set.
Before installing the AdvanTech sheathing, the carpenters cut slots for biscuit joints in the butt ends of the panels.