Framing the floor deck.

This stage of construction takes us back to somewhere near the end of august 2011. I had completed framing the basement walls, and had put up the load bearing basement partition walls that support the floor framing. I used engineered I-joists, rim board and LVL beams, then 3/4" tongue and groove plywood as a subfloor. Never having built anything using engineered lumber before, I was impressed by how straight everything was and how well everything fit together - which I guess is the whole point. The entire floor structure was built on one plane, which is to say that the joists were fastened to the structural beams using hangers, creating a flat ceiling in the basement.

The completed floor deck. The poly in the center of the floor is covering the hole for future stairs and stovepipe. During assembly, I was careful to install the "smooth" side of the rim board to the exterior, so the airstop tape would stick (more on this in later posts). I waited on the application of the airstop tape to the rim board until the last possible moment so as to avoid unnecessary UV exposure.

Road map.

With my last post, we pretty much came to the end of the foundation work. I'm sure there will be a few revisits in the future, but now I'm looking forward to getting into all the other stuff. At a couple of points I had skipped ahead and made a few posts on some of the framing and airsealing work. In this post I wanted to start this new phase of the blog by laying out a "road map" - so as to show where I've been and where I'm going.

At various points throughout this project, I have had moments where the end goal seemed almost impossibly far away. During those moments I always found it useful to break the journey down into smaller pieces and simply focus on the next task - one task at a time and the next thing you know, you've made substantial progress.

"Wing" insulation, drainage and parging.

With the foundation insulation done, it was time to turn my attention to insulating the ground around the foundation. This insulation for the ground is sometimes called "wing" insulation and is an important part of the FPSF foundation design. The wing insulation effectively protects the shallow footings from frost heave by raising the frost line towards the surface. In my case the insulation plan called for R20 insulation extending outwards 4' from the footings but 6' at all corners (except where the footings were more than 6' below final grade).

The colder the climate, the higher the R value the wing insulation must provide to keep the earth below from freezing. Also, the colder the climate, the further the wing insulation must extend outwards from the foundation. When the underside of the slab and footings are insulated as well, the R value of the wing insulation must be increased more still since reduced heat loss from the underside of the foundation will contribute less towards keeping the earth under the footings from freezing.

Waterproofing and insulating the rest of the foundation.

I was very excited to be done with the concrete work - it was  a big job and I was really looking forward to setting my own pace with the rest of the project. Before I could do that, however, there was one last reason to bring out a couple of the concrete guys again - the "Blueskin". Applying the "Blueskin" waterproofing membrane wasn't terribly difficult, but I wouldn't want to try it single handed - it's too sticky, awkward and expensive.

4" rigid foam around the exterior wall makes a good capillary break but something more is required to fight hydrostatic pressure. We applied the "Blueskin" membrane only to within 12" of the top of the wall to save material - this stuff 'aint cheap. The black line around the top is a mastic "goo" that seals the edge of the membrane to the wall.