Basement Insulation and Framing Work Is Underway
Posted from: MD, USA
Today PanelWrights arrived onsite and began preparation for the basement wall and first floor framing work.
When I arrived they had already set down the 2×8 treated wood plates at the top of the foundation walls. These sit on top of a sill sealer and and added layer of sealant, and are fastened with steel bolts down into the concrete. You can see the plate at the top of the walls in the first picture.
While some men were setting the wall plate, others were caulking the joint between the concrete slab and the foundation walls. I wrote in our Aug. 8 blog post that we were going to use a termination bar to seal the StegoWrap vapor barrier to the foundation wall. Keith came up with a better idea: cut the StegoWrap at the top of the slab and embed it in sealant. Katrin Klingenberg liked the idea and suggested we add a layer of butyl tape over the sealant as an insurance measure. In the second picture you can see the sealant to the right and the butyl tape to the left as it is being applied.
Katrin also recommended that we apply 2” of EPS rigid foam to the interior face of the foundation wall. The idea behind this is that with the extra insulation we are ensuring that there will be no condensation of any warm moist air on a cold concrete surface. In the third picture you can see the rigid EPS board set against one of the foundation walls. The yellow stuff you see is closed cell foam insulation from a can (GreatStuff). Just prior to installing each board of rigid insulation, they sprayed a bead of this stuff at the bottom and the sides of each piece, then pushed the rigid boards into place. This is simply an added measure of security to keep the wall airtight and eliminate any gaps in the insulation. Like most things in Passive House construction, rather than using expensive and hi-tech new products, we are simply taking a little more care in how we put the house together.
As I left the site, the PanelWrights crew was putting down the treated pine floor plates for the stud walls that will go up inside the foundation walls. You can see the this in the fourth picture. Tomorrow the steel posts and the central bearing steel beam will be set in place and the floor framing will begin. That should be complete by Thursday.
The last picture shows one of the SIP wall panels which are now being delivered to the site. You can see that the foam is recessed at the edges. This is done so the panel can straddle the top of the wall plate and the OSB sides anchored to the plate. More on this as they begin going up in the next weeks.