Residential Building Inspector B1Floor ConstructionHard
A residential building inspector is examining a floor system that uses steel C-joists. The plans indicate that the joists are 8 inches (203 mm) deep. For proper lateral support and to prevent rotation, what is the maximum spacing required for bridging or blocking between these C-joists?
- A8 feet (2.4 m)
- B5 feet (1.5 m)
- C10 feet (3.0 m)
- D6 feet (1.8 m)
Show answer & explanationAnswer & explanation
Correct answer: A. 8 feet (2.4 m)
According to the IRC, steel C-joists require bridging or blocking at intervals not exceeding 8 feet (2.4 m). This spacing is crucial for providing lateral support, preventing rotation, and distributing loads effectively across the floor system.
Why the other options are wrong
- B. 5 feet is not the maximum spacing specified by the IRC for steel C-joists.
- C. 10 feet exceeds the maximum spacing allowed by the IRC for steel C-joists.
- D. 6 feet is not the maximum spacing specified by the IRC for steel C-joists.
Steel C-Joist Bridging/Blocking Spacing
Steel C-joists require specific maximum spacing for bridging or blocking to ensure lateral stability, prevent rotation, and enhance load distribution.
- Maximum 8 feet (2.4 m) on center.
- Essential for lateral support and preventing rotation.
- Applies to steel C-joist floor systems.
Memory trick: Eight feet max for steel's straight run.