What do you assess in building a house foundation? Soil conditions of every area will determine what kind of foundation should be built. Soil conditions will all be different. When beginning a house foundation, find a structural engineering firm.
A house foundation is forever and attention to details is important when building one to ensure it will remain dry and crack free. Foundation walls should be plumb, leveled and free of discolorations; if not these are signs of a weak concrete. Slab foundations should have sturdy footing and a vapor proofed, reinforced concrete pad sitting on a bed of compacted crushed stone, says Tom Silva, the host of This Old House at thisoldhouse.com.
When starting your foundation, the best thing to do is hire a structural engineering firm. Structural engineers will be the first to board test the soil. Once they have tested the soil, the engineer can design a specific slab for the specific soil conditions. "A lot of people do not do this because they do not want to pay any extra cost," says Jeffrey Ellison, who has seven years of experience in foundation repair and construction. He works for two major foundation companies in Austin, Texas. "It is usually between $300 to $800 to get an engineer involved on the project, but that is money well spent for the homeowner."
According to Ellison, when building slab foundations, soil conditions are very important. Different builders have different standards on what type of soil they will build on. A lot of the higher end builders can give you more square footage for your money, and will build in areas where the most expensive builders won't build. However, they do not do as much soil testing or board testing and within a couple of years the foundation of the home needs to be repaired. It is extremely important to soil test. One of the reasons we have so many foundation problems is due to the clay content of the soil. Texas is second only to California in foundation repair claims per capita. California's problems are a result of earthquakes and mudslides. However, in Texas we have very high clay content in the soil. With the exception of the hill country, a majority of the clay content is a mix of limestone and clay. Then, as you head south and east toward Houston, it turns into black clay; the slang name is called black gumbo. Both of these soils have very high clay content. Clay has a high plasticity rating, which is the industry term for how much a soil expands and contracts with changes in moisture. All soils do it, but clay based soil sod is three times more than any other type of soil, so it is like living on a sponge. Before building a home, all foundation contractors need to watch out for clay content.
On his website, Tom Silva says a good foundation needs to have steel enforced foundation walls and footings made of poured concrete. By comparison, all the laboriously assembled foundations of stone, brick, and mortar that have supported buildings for centuries are prone to cracks and leaks. "It must be tailored to its site like a custom suit, taking into account soil conditions, water tables, even the quality of the backfill."
