Building a High-Performance Shell, Images 11-17

A galvanized metal flashing, air-sealed to the rim and foundation with adhesive, provides a starter strip for the foam sheathing and protects the bottom edge from burrowing bugs, rodents, and flying sparks. The attached insect screen was later folded up over the ends of the vertical vent strips behind the siding.

Expanding foam seals random cutouts in the rim joist. The first layer of 2-inch foam is installed vertically and sealed and bonded to the frame with adhesive.

The second layer installs horizontally, overlapping in an alternating weave at building corners.

Air-sealing tape is used on the first layer where it intersects the projecting window bucks.

Before framing the unheated attached garage, the author applied foam sheathing to the common wall, establishing a thermal break between the two structures.

Structural screws driven through the foam tie the isolated frames together. Here, the author anchors a walk-out bay rafter to the wall framing.

With the foam sheathing serving as a drainage plane, 1x3 vertical strapping creates a venting and drying space behind the siding. Additional strips around windows and doors provide separate backing for trim and siding.

Join the Discussion

Please read our Content Guidelines before posting

Close X