Residential Building Inspector B1Footings and FoundationsEasy
A building inspector is examining a newly poured concrete footing. According to the 2021 IRC, what is the minimum thickness required for a concrete footing supporting a residential wall?
- A12 inches
- B6 inches
- C4 inches
- D8 inches
Show answer & explanationAnswer & explanation
Correct answer: B. 6 inches
The 2021 IRC R403.1.4.1 specifies that concrete footings shall have a minimum thickness of 6 inches.
Why the other options are wrong
- A. Incorrect. 12 inches is typically thicker than the minimum required for standard residential footings.
- C. Incorrect. 4 inches is generally too thin for residential footings according to the IRC.
- D. Incorrect. While 8 inches might be used, it's not the minimum required by code.
Minimum Concrete Footing Thickness
The smallest allowable vertical dimension for a concrete footing supporting a residential wall, as specified by building codes.
- Ensures adequate strength to distribute loads.
- Prevents punching shear failure.
- Specified in IRC R403.1.4.1.
Memory trick: For a footing, think six solid inches to stand on.