I do not know if this is unique to the Essex ON area and Michigan but our building dept requires the following: Anything under 530 s/f can be pad build (no 4' frost wall IF you use an 18" rat wall.
OK this is good because I was doing what is called a frost protected shallow foundation. It is basically slab construction with 2' rigid foam wings around the foundation. VERY simple to build with 2X6s, ply and foam. Only have to dig down about 1'6", gravel 6" and foam. The design relies on the fact no water collects under the foundation so none can freeze and heave it. The actual document for canada is here: http://publications.gc.ca/collections/collection_2011/schl-cmhc/NH15-457-1998-eng.pdf
OK, so if I was to use that I still have to go down another 12" for the sake of a rat wall as shown here:
My question is (and I will make the argument to the BD) Will this not totally defeat the idea of letting the water drain out a basin and away from the foundation? In other words, does it not then basically become an inverted bathtub?
OK this is good because I was doing what is called a frost protected shallow foundation. It is basically slab construction with 2' rigid foam wings around the foundation. VERY simple to build with 2X6s, ply and foam. Only have to dig down about 1'6", gravel 6" and foam. The design relies on the fact no water collects under the foundation so none can freeze and heave it. The actual document for canada is here: http://publications.gc.ca/collections/collection_2011/schl-cmhc/NH15-457-1998-eng.pdf
OK, so if I was to use that I still have to go down another 12" for the sake of a rat wall as shown here:
My question is (and I will make the argument to the BD) Will this not totally defeat the idea of letting the water drain out a basin and away from the foundation? In other words, does it not then basically become an inverted bathtub?