What is the minimum thickness of a footing for a single-story frame residence?

What is the minimum thickness of a footing for a single-story frame residence?

• A. 6 inches
• B. 8 inches
• C. 7 inches
• D. 4 inches

Answer: (A)

The main idea here is that footings must have enough cross-section to transfer the wall load safely into the soil. For a typical single-story frame house, six inches of concrete in the footing is the minimum that provides adequate strength and bearing resistance without wasting material. A thinner footing, like four inches, would be more prone to cracking, settlement, or insufficient bearing under even ordinary loads. Increasing thickness to seven or eight inches isn’t necessary for standard single-story designs and would simply raise material costs without adding meaningful benefit under normal conditions. In real projects, the exact footing size also depends on soil bearing capacity, frost depth, and wall loads, so engineers may specify larger footings if those factors demand it—but the minimum for a standard single-story frame is six inches.

The main idea here is that footings must have enough cross-section to transfer the wall load safely into the soil. For a typical single-story frame house, six inches of concrete in the footing is the minimum that provides adequate strength and bearing resistance without wasting material. A thinner footing, like four inches, would be more prone to cracking, settlement, or insufficient bearing under even ordinary loads. Increasing thickness to seven or eight inches isn’t necessary for standard single-story designs and would simply raise material costs without adding meaningful benefit under normal conditions. In real projects, the exact footing size also depends on soil bearing capacity, frost depth, and wall loads, so engineers may specify larger footings if those factors demand it—but the minimum for a standard single-story frame is six inches.