Residential Building Inspector B1Wall Construction and Wall CoveringsMedium
A builder is constructing a residential basement wall using concrete. The wall is 8 feet high and will retain earth. What is the minimum specified compressive strength (f'c) required for the concrete used in this wall?
- A3,000 psi
- B2,500 psi
- C2,000 psi
- D3,500 psi
Show answer & explanationAnswer & explanation
Correct answer: B. 2,500 psi
According to IRC Table R404.1.2(1) and R404.1.2(2), for concrete basement walls retaining earth, the minimum specified compressive strength (f'c) is 2,500 psi. This ensures adequate strength to resist lateral soil pressures.
Why the other options are wrong
- A. 3,000 psi is commonly used and provides ample strength, but it is not the minimum required by code for this application.
- C. 2,000 psi is generally too low for basement walls retaining earth and would not meet code requirements.
- D. 3,500 psi is typically used for higher strength requirements or specific structural applications, exceeding the minimum for a standard basement wall.
Concrete Basement Wall f'c
Concrete used for basement walls retaining earth must have a minimum specified compressive strength (f'c) of 2,500 psi.
- Applies to cast-in-place concrete basement walls.
- Ensures resistance to lateral earth pressure.
- Refer to IRC Tables R404.1.2(1) and R404.1.2(2).
Memory trick: For a strong basement wall, two thousand 'Five Hundred' psi is the concrete minimum.