In conventional light frame construction on soil with a load bearing value of 2,000 psf for a one story building with 8 inch hollow concrete masonry walls, what is the minimum thickness of the spread footing?

In conventional light frame construction on soil with a load bearing value of 2,000 psf for a one story building with 8 inch hollow concrete masonry walls, what is the minimum thickness of the spread footing?

• A. 24 inches
• B. 12 inches
• C. 6 inches
• D. 15 inches

Answer: (C)

Distributing the wall load safely into the soil is the key idea. A spread footing must be thick enough to resist bending and shear from the wall while spreading the load over soil that can safely carry it. For conventional light-frame construction on soil with a bearing value around 2,000 psf and only a one-story building, six inches is the standard minimum thickness for a spread footing. This depth provides adequate concrete coverage and space for reinforcement, and it is sufficient to carry the loads from an 8-inch hollow concrete masonry wall without exceeding the soil’s bearing capacity. Thicker footings would be unnecessary here unless the loads were higher or frost considerations required deeper footings.

Distributing the wall load safely into the soil is the key idea. A spread footing must be thick enough to resist bending and shear from the wall while spreading the load over soil that can safely carry it. For conventional light-frame construction on soil with a bearing value around 2,000 psf and only a one-story building, six inches is the standard minimum thickness for a spread footing. This depth provides adequate concrete coverage and space for reinforcement, and it is sufficient to carry the loads from an 8-inch hollow concrete masonry wall without exceeding the soil’s bearing capacity. Thicker footings would be unnecessary here unless the loads were higher or frost considerations required deeper footings.