Creating a "Superior" Foundation

I'm still amazed to see where we are in construction today given the winter we had. We started the first week of January with site work to prepare for the foundation. This entailed creating a construction boundary with a silt fence around the perimeter of the work area (more like a snow fence!!!). We also protected a few trees, albeit with piles of snow rather than fencing given the ground cover. Soil was placed in one corner of the site (adjacent to the existing cottage) before excavation commenced. Our soil type is mainly clay, and our footing mix consists of 18" of crushed stone, with 4" under drain. Wall footings are 60" wide, with 10" of stone as well. Once this was done, everything was covered for a night to keep frost at bay. The next day, our Superior Walls(TM) arrived from nearby Lima, NY. We decided to go with these precast walls vs. concrete block for a number of reasons:

1. Our actual Superior Walls product is the Xi (meaning extra insulation). They provide an excellent thermal barrier because they have fewer seams, and they have the first layer of 2" rigid foam insulation embedded in them (an R12.5 in our case). The total wall thickness is 8'8", and the remaining cavity can be filled with whatever insulation we choose. We're still debating fill material at this time, and are considering dense pack cellulose as well as closed cell spray foam.

2. Engineering off-site ensures a minimal amount of waste, some of which can be reclaimed at the production facility and reincorporated into the production process. Additionally, there's no packaging waste on the job site, as the panels arrive on flat bed trucks ready to be lifted by crane into place.

3. At all seams between panels, workers applied a construction adhesive to ensure an air-tight bond. Each piece was bolted before being sealed again along the outside seam (see below, left) as well as inside each cavity (below right). A good portion of this wall will be below grade once site work is complete.

4. Finally, the pre-fabricated walls proved to be superior in light of our climate: very cold temperatures can make constructing traditional concrete block foundations on site difficult, if not impossible. Within one week of our wall's placement, we had topped off the foundation level, and the basement floor could be poured, giving us our foundation in an impressively short time frame. Here's a link to Superior Walls website where they discuss some of their "green" features:

http://www.superiorwalls.com/greeninfo.php

Note: Foundation drainage is VERY important, and is normally covered by most state and local codes, as well as the durability guidelines in LEED Homes. Our builder used flexible PVC pipes around the foundation walls, beginning at the high point (garage side, east) and directing water to a french drain constructed downslope at the northwest corner of the property. When we had our first big melt in early March, we were pleased to see just how much water flowed through the drains to this outlet.