Footings.

Using a simplified foundation plan I had made from the architect's plan, the concrete contractor and I marked out the outer edge of all the perimeter footings and the center-lines of the peninsula footings. Even with the slim steel pins we were using, it was difficult to drive them into the compacted gravel. A string line was stretched between the pins to outline the house's footprint.

With the string line in place, I had a few days to rough in my below grade plumbing. My plan is to eventually tie into my existing septic tank and field. Fortunately, the inlet at the septic tank is down slope enough that I can rely on gravity and not an ejection pump. For a long time before we started the initial excavation work, I thought for sure that I would need an ejection pump. When I shot the elevation after excavation, I was surprised to find that it was just perfectly down slope of the house.

I had already installed a run of 4" ABS from within 4' of the septic tank inlet to a spot that I figured (after much fussing) would be directly below where the main floor toilet would be. The rough-in work was pretty easy since the top of the gravel pad was already 10" below where the sub-slab rigid foam would be. I only had to do a little scraping with a pick at the low end and I did have to dig a hole around the existing 4" drain to install a "wye" and a 45. The worst part was the mosquitoes in the evening. In addition to the plumbing, I installed a run of 3" ABS as an air supply for the woodstove.

The drawing I submitted for my permit.

A few days later, a couple of guys came out to really level the gravel where the footings were going to be poured. I thought the pad was already pretty level (I could only come up with at most a 1/2" variation using a laser level) but these guys got it down to something close to an 1/8" by either raking down high spots or adding material and packing with a little plate tamper.

After leveling, the footing forms were brought in. My contractor had 12" panels for the interior footings but the 18" panels for the exterior perimeter had to be built from scratch. I worked with his crew under the very hot sun pounding stakes, leveling and bracing forms, fitting and trimming rigid foam and laying rebar. With seven people (including myself) we finished everything in a little less than two eight hour days - this included lots of extra breaks to prevent heat stroke. The rigid foam was installed as per my drawing in "Planning for the foundation". The foam boards fit snugly in the forms and didn't require any special bracing or fastening to keep them in place for the pour. I pushed several 3 1/2" ardox nails into each foam board at odd angles so that they would stay in place on the concrete after the forms were stripped.

Four courses of 15 millimeter rebar with stirrups 24" o.c.
The vertical bars are also 15 mm and are what tie the
basement (concrete) wall to the footings. Zoom in to
see the ardox nails in the foam.

The top two courses of rebar were set to protrude into
slab above. Notice how the forms at the exterior side
rise above the footings by 5" to form the slab edge. Also
notice that the inner forms have been stripped and the
foam boards remain firmly in place.