Armed with the soil compositions and depths, I met with the excavators once again. This time they brought the transit and “shot” the grade. Based on a 24×40′ building, he came up with these numbers.
Based on those measurements, we would cut into the hill 27″ at the SE corner, add 7″ on the SW corner, cut 16″ on the NE corner and add 3″ on the NW corner.
The west side of the building would be built on the filled area so the building footings from the SW to the NW corner would go down an additional foot to 60″. At that depth, the footings would be set on ‘virgin’ grade and would be much more stable.
We had a plan that everyone approved. Except now I had a lot more work to do around the building. I would need to build retaining wall on the west side to keep the dirt in place. There was already a wall there but it was well below grade and had pretty much failed. I would also need to build a small block wall to hold back where the building would be cut into the existing grade. I’d also need to handle drainage a little different