First Floor Walls

Well it's been a few weeks since my last entry. A lot has happened since then but much of it was not terribly exciting.  Necessary, but not worth writing home (blogging) about.  Immediately after the foundation was complete, the first floor was constructed. Next, the basement was completed, holes were drilled in the basement walls for the geothermal system, drainage pipes were put in by the basement windows, and underground conduit was put in for electrical cables. After that, a whole lot of back-filling around the walls made the site look much more "presentable."

Basement covered (Click image for more photos.)

Because the foundation was constructed using Superior Walls, it was necessary to "cap" the walls with the first floor and pour the concrete for the basement floor before they could back-fill completely (this helps stabilize the foundation).  It was pretty neat to get a "floor" on top of the foundation so we could walk around on it, and the kids loved watching the concrete get poured down the stairwell hole.  We also had our first real mishap on the project, a broken basement window (courtesy of our general contractor Robin).  Oh well...if that's the worst thing that happens, we'll feel pretty fortunate.

Soon after the foundation was done, the wall panels were supposed to go up.  Unfortunately, scheduling conflicts pushed this off for over a week.  We are using Structural Insulated Panels (SIPs) for the walls and a portion of the roof.  SIPs are pre-fabricated panels consisting of a core of rigid foam insulation sandwiched between two sheets of oriented strand board (OSB).  Basically, it's an insulation sandwich.  Since the insulation completely fills the space between the OSB skins (except where there are holes for electric) and there are no studs to act as a thermal bridge, the effective "whole wall" insulating value of a SIPs wall is significantly higher (about 30%) than a traditional wall of the same thickness.  In addition, there is very little chance for air leaks in a SIPs wall, resulting in a much tighter, quieter, and more efficient building envelope.

On Wednesday, January 27, the panels arrived.  It was quite interesting to watch the panels being unloaded.  They attached a forklift attachment to a bulldozer and unloaded them a few at a time.  Sounds simple enough except that the panels are pretty big and there was not a lot of room for maneuvering.  I was a bit tense watching as it looked like a disaster was just waiting to happen.  But everything went pretty smoothly and the panels were all unloaded safe and sound.

Unloading SIPs (Click image for more photos.)

On Friday, January 29, the panels started going up.  Because there are no studs, the panels themselves are not tremendously heavy.  They are designed with a groove in the bottom that slides neatly over the top of a two-by-six board nailed to the floor (sort of like a tongue-and-groove floor connection).  Glue is applied when the panel is laying flat and then two guys push it up and two others hold it in place.  The next panel is similarly prepped and glued to the first.  Where the two panels come together, additional OSB strips are slid into place at the seam to block any potential air path.  When everything is leveled and satisfactory, the panels are nailed to the floor and to each other.  Later, when the electrical is all in place, they will seal the seams with spray-foam insulation.

Because the panels were all pre-cut off site to the exact specifications of the plans, they fit together beautifully like pieces of Lego.  I was quite surprised to see just how well everything fit with almost no (on-site) waste whatsoever.  Wow - in a matter of a few hours, it really started to look like a house.  By late Saturday, all of the first-floor walls were up and we could walk around inside.  In addition, they had drawn on the floor where the interior walls were going to go so we could really start to get a sense of what the interior was going to be like.  What a thrill!

First floor finished (Click image for more photos.)