A carpenter sets up a jig to mark and cut the top ends of the wood I-joists for the wall at an angle matching the roof slope.
A carpenter snaps a layout line for the wood I-joist on the house wall. I-joist flanges line up with studs in the wall, and are screwed into the studs using GRK structural fasteners. The taped OSB skin on the inner stud wall serves as the airtight barrier for the building.
Here, the carpenter screws a short length of I-joist into the wall above the window buck. At the intersection between the walls and the roof, the wall I-joist cavity meets the roof I-joist cavity and allows for continuous insulation over the joint, with only minimal interruption where blocking has been installed.
The carpenter sends a screw home from the wall I-joist flange into the roof I-joist flange. Roof sheathing will come down across this joint and terminate at the outboard face of the wall I-joists.
A view of the wall corner cavity, formed by an assembly of wood I-joists. The vertical insulation cavity here, once dense-blown with cellulose, will virtually eliminate thermal bridging at the wall intersection (a key consideration in Passive House construction methods).
Framing out wall blocking at the outboard edge of the OSB window buck. The Marvin windows chosen for this project have a nailing fin, for which this blocking will provide an attachment point. Kruse will have to integrate that nailing fin into the vapor-open drainage plane membrane to be applied later over the I-joist wall assembly.
Completed window bucks, including blocking, for small windows on the building’s north wall. Tape over the OSB skin beneath the I-joists helps form the building’s air barrier. The corners of the window bucks are also taped, to integrate the window framing into the air barrier. An exterior drainage plane membrane, and strapping for the siding, will be applied next. Flanged windows will be fastened to the 2x4 blocking surrounding the OSB window bucks.
Another view of the completed window bucks, showing the ProClima Tescon VANA tape used for air-sealing the OSB skin and the window buck joints.
A framed opening for a large south-facing window. South-facing windows will supply solar heat gain in winter and also provide a pleasing view of the nearby hills and ski slope to the south.