More Passive House details
The Outsulation is now being installed on the envelope of the entire project. The Panelwrights crew is battling windy conditions that make installing exterior sheet insulation (Outsulation) and house-wrap a difficult exercise. This stage of the process is critical to addressing all the potential areas where a thermal bridge could allow the loss of energy through the wall assembly.
All windows and doors get a perimeter of dimensional lumber and high density EPS. The foam has a compressive strength of 25psi and the dimensional lumber is screwed tight to the perimeter with Trufast screws. These heavy duty fasteners allow the dimensional lumber to act as a solid attachment for the window flange. In addition, the foam disconnects the thermal bridge of the imbedded lumber in the SIPs which surrounds the window and door openings.
This north wall is being covered with the standard two layers of EPS foam. The sheets are staggered and screwed in place awaiting a covering of house-wrap and vertical batons.
Notice the two layers of foam and how they cover the area where solid lumber would effectively bleed energy from the structure. The lower horizontal band is both the blocking for the transition trim between siding and foundation as well as the solid support for the vertical batons. This band is also held off the structure by high density EPS.
In addition to our work on the exterior, the other trades have begun their own installation. Due to a pre-construction meeting, all the trades are well versed in the correct way to approach this project. For a successful build, every member of the building force has to understand the importance of preserving the integrity of air-tightness in the envelope. We have identified every penetration in the entire envelope and then detailed the specification for both making the penetration and subsequent sealing.
This clearly shows how the plumber cut an oversized hole in the envelope before inserting the PVC pipe. This oversized hole allowed the Panelwrights to inject a single component foam in the space around the pipe and get a perfect seal.
The window package has been partially delivered and the installation is underway. If all stays on schedule, we should have a blower door test that will let us celebrate a very Happy New Year.