Thermographic imagery revealed empty wall cavities (top), air infiltration around windows (center), and cold spots around framing members like corners and plates (above).
The crew stripped off the old cedar shingle siding, focusing on one side of the house at a time to protect the exposed walls and insulation from the weather.
After removing trim from the old windows (this frame was fitted with new jamb liners and replacement sash), crew members filled voids and gaps around the frames with spray foam.
The walls were wrapped with 1-inch-thick sheets of polyisocyanurate foam, which adds R-6 to the wall assembly and acts as an air and vapor barrier and drainage plane. All joints — including gaps between the rigid foam and jamb extensions — were foamed.
Battens ripped from 3/8-inch plywood were fastened through the foam and sheathing into the wall framing to provide solid nailing for the fiber-cement siding and create a drying airspace behind it.
Strips of 3/8-inch-thick Cor-A-Vent installed along the base of the wall between the battens keep out insects.