and God said, “build on the rock”...

With the septic and well finally in and the trees removed from the footprint of the house the next step was to scrape off the thin topsoil and expose the bedrock. My plan was to pour the footings directly on the rock, build up a short wall of block, backfill behind the block (inside the outline of the house) with crushed stone and then pour a slab on top - all of this to elevate the slab to get the proper slope for the plumbing drains to the now properly elevated septic system.

The exposed rock presented a very uneven surface with some solid ledge but also many boulders and soil-filled pockets that were difficult to remove. To satisfy a condition of the building permit I had a soils engineer come out to determine if the rock was in fact frost susceptible and the unfortunate conclusion was that it was. Covering the footings with five feet of backfill (the minimum for frost protection in our part of the world) was out of the question but keeping the heat in the ground next to the footing with rigid insulation would achieve the same result.

The first step though would be to lay in and compact a layer of gravel (Granular B - 2” minus, to be exact) to fill in some of the nooks and crannies, provide some drainage under the footings and make the job of forming the footings much easier.















The process of installing the “B” went according to plan and even offered me the opportunity to drive a piece of heavy equipment. Well not such a heavy piece of equipment, in fact it was the smallest ride-on compactor they make, but rumbling around on this thing gave me the brief illusion I was a serious contractor. After a couple of hours of this tooth rattling process, having nearly tipped the damn thing over several times, it was time to hand the keys back to the real operator and get the soils guy back out to do a “Proctor Density” test on the gravel pad.















The engineering tech showed up with a Nuclear Density Meter:

“Nuclear Density meters are a quick and fairly accurate way of determining density and moisture content. The meter uses a radioactive isotope source (Cesium 137) at the soil surface (backscatter) or from a probe placed into the soil (direct transmission). The isotope source gives off photons (usually Gamma rays) which radiate back to the meter's detectors on the bottom of the unit. Dense soil absorbs more radiation than loose soil and the readings reflect overall density”.















I hadn’t seen one of these before but I could tell from the skull and crossbones on the thing that I would be best to stand back. The technician on the other hand stood over the device with it positioned squarely between his legs. I asked him if he had any kids, to which he responded “three”. I then asked if they were normal, to which he laughed and said “absolutely not”...















With the gravel pad in and compacted to spec it was time to pour footings. I decided early on to use “Fastfoot” for the footing, a fabric forming system that is ideally suited for the uneven surface I knew was down there. Fastfoot offers the additional benefit of creating a capillary break with the ground so that moisture isn’t wicked up further into the foundation - not a huge benefit in my case with the slab so far above the footing but a real advantage with a basement or crawl space.















































































The product worked as advertised, making the job of forming footings on my sloping gravel pad much easier and faster than lumber forming would have been. Unfortunately by the time we came to the garage we had run out of the adjustable frames used to support the 2x4 rails and fabric so on this relatively flat part of the site we framed the footings the old-fashioned way and just lined them with Fastfoot to get the capillary break.

The concrete pour went well, in part because of my new neighbor Dick and my friend Barry, who just showed up unbidden at the right time with rubber boots and trowels. As the concrete set George and Jesse pounded vertical bars into the footing to fix the foundation wall. Two hours later we all stood back and stared at this dull grey spikey line of concrete snaking around the site, marveling at what was the first trace of the actual house itself.