Now that we have created a pretty airtight structure we can begin poking holes in it.
To ensure our next blower door test is as good as the 1st one we have to maintain our air barrier.
Cut open the window rough openings
I was very impressed at how well the inner wall and outer wall rough openings lined up!
With the Zip board removed, we used 6" Grace Window flashing to extend the Zip System to the inside face of the inner wall.
With the air barrier extended into the house we can build the solid window buck.
We chose to use 1/2" zip board (the cut out section of the window) for the 2 sides and top. We used left over sub floor for the sill. I figured the thicker sill material would be a good idea with a heavy window suspended between the 2 walls.
Now we need to install our 2" rigid foamboard to insulate the window buck and prevent "short circuiting" around the window frame
Install beveled rigid foamboard to window sill to allow for water drainage
Wrap window buck foamboard with Solitex Mento. The Solitex Mento will be the connection between the Grace 6" tape and the inside surface of the window.
Install stop blocks on the outside of the window opening so the window can be lifted and pushed flush to the stop blocks
Prep the window - For fixed pane windows a metal clip is inserted into the UPVC frame. We can then screw the metal clip through the rigid foam into the solid buck.
For operable windows we predrill holes though the UPVC frame. Once the window is in place we can install the screws from the Manufacturer.
Shim window and screw into place. Once in place we removed all of the shims (except for the bottom).
Seal the window in place
We filled the void between the Mento and the window with low expanding foam. Then we taped the Mento to the Window on all 4 sides.
I hope this helps show that the detail of installing the Passive House Windows is just as important as the window itself.
The door install is very similar with a little change to the threshold.
Because the low profile threshold of the doors (The bottom of the door is only 3/16" above the bottom of the frame) we cannot install to door directly on the subfloor. We raised the door 1" with a combination of rigid foamboard and pressure treated lumber to maintain a thermal break and still give the stability due to the weight of the door. This way the depth of the flooring will not interfere with the operation of the door.
Also, since the exterior doors are all in-swing we wanted to allow for full 180 degree swing. We installed the door to the inside of the wall assembly.
With the windows and doors installed (except for the front door) we can begin the installation of our Rain Screen in conjunction with Rough Plumbing and Rough Electric. Our 2nd Blower Door test will be coming shortly as well!