North Carolina Building Contractor License Practice Exam

Trimmer and header joists must be doubled when the span of the header exceeds what length?

1. 4 feet

2. 6 feet

3. 8 feet

4. 10 feet

The correct answer is: 8 feet

In building construction, particularly in framing, trimmer and header joists are critical for supporting the load of structures, especially when framing openings like doors and windows. Doubling these joists enhances their strength and load-bearing capacity, particularly when the header spans exceed a certain distance. When the span of a header exceeds 8 feet, it is necessary to double the trimmer and header joists to provide adequate support. This requirement is in accordance with standard building codes and practices that ensure structural integrity and safety. Doubling the joists helps distribute the weight and reduces the likelihood of sagging or failure, which can occur if the joists are not adequately supported. Construction professionals must follow these guidelines to ensure the safety and durability of their structures. Understanding the specific requirements for joists, headers, and other framing components is essential for compliance with building codes and maintaining a strong structural framework.