How Much Concrete Is in a Typical House Foundation?

Floor

• To figure the amount of concrete that goes into a home's foundation, begin with the basement floor. The volume of the floor, which is usually concrete poured in a wooden mold with steel reinforcing bars throughout, is equal to the square footage of the basement floor times the thickness of the floor. While steel reinforcement consumes some of the volume, concrete measurements for a foundation aren't precise since some concrete is wasted in the building process, and more concrete than will be needed is actually ordered and mixed.

Walls

• Concrete basement walls can be built in one of two ways. The first is using a poured-concrete method, similar to that used for a basement floor. The other uses prefabricated, hollow concrete blocks, which can be filled with reinforcing steel, poured concrete or insulation. The volume of each wall is equal to its height times its length, times the thickness of the wall. Taller walls require greater thickness to have the same strength as shorter walls, so building a poured-wall basement increases the amount of concrete in terms of both additional height and wall thickness.

Footings

• Some concrete foundations also include poured footings, which are buried beneath the basement floor for additional structural support. Poured concrete footings are used when homes are build in areas where the ground is subject to frost during the winter. The amount of concrete used in a footing can be measured as an extension of the wall below the level of the basement floor. However, the footing may be thicker than the wall, consuming additional concrete.

Typical Example

• The size and shape of a home's footprint has a major impact on the amount of concrete that goes into the foundation. A two-story, 2,000-square foot home may have a base that is 50 feet long and 20 feet wide. This means that the basement floor has a surface of 1,000 square feet. Given a thickness of 4 inches, the floor alone requires almost 12.5 cubic yards of concrete. If the same home has 8-foot-tall basement walls that are 8 inches thick, and no footings, the total amount of concrete in the foundation is around 40 cubic yards.