Step 1: Geotechnical Study
The geotechnical study evaluates the ability of the ground to support the structure, water drainage, and other relevant items. It goes on to make a series of recommendations for the build.
Two bores were taken on the lot to a depth of 12 feet. These bores are examined to determine the soil type and moisture level. A standard penetration test (aka blow test)is also performed on each. This involves driving a tube into the ground using a 140 pound weight dropped from a height of 30 inches. The tube is driven 6″ into the ground and the number of blows required is counted. This indicates the firmness and density of the ground at the bottom of the whole.
My geotechnical study found:
- The top 6″ of the soil were a slightly sandy/silty clay.
- The remaining 11′ 6″ were clay.
- The clay was stiff to very stiff.
- Ground water wasn’t encountered at either site.
The geotechnical study made a variety of recommendations including
- Uniform 12″ lifts on all foundation walls.
- Drainage around the house requires a 1 foot slope per 10 feet of dirt compacted to 96% of its maximum dry density.
- Roof downspouts need to discharge of a minimum of 5-10 feet from the house.
- Landscaping requiring irrigation should be at least 5 feet from the foundation.
- Footings need to be a minimum of 16″ wide.
- Spread footings need to be placed a minimum of 3′ feet below ground level, except for exterior spread footings which must be 3′ 6″ below ground level. This depth ensures that they are below the frost level. Each footing must support 2500 pcf and be built on top of 18″ of structural fill compressed to 98% of maximum dry density.
- Floor slabs must be at least 6″ below the existing grade and have at least 6″ of compacted fill beneath them.
Step 2: The Dig
The dig was subcontracted out. Pictures are below.
Step 3: Footings
Yesterday (Dec. 12th) afternoon the forms for the footings were put in place. The photos below are a combination of those taken this morning before the concrete was poured and those taken this afternoon during the pour.
The entire foundation process has taken a long time. Sheridan had one of their two concrete companies go out of business. The other isn’t equipped to deal with the additional demand. Hence, the shortage has impacted many projects in the Sheridan area, including my house.
Step 4: Foundation
On Monday, the concrete subcontractor will begin putting the forms in place for the foundation. It’s a bit of an involved process that will take them about a week. They should be able to pour the foundation sometime around 12/21 – 12/26.
<<More to come.>>