ICC Commercial Building Inspector Practice Test

What is the maximum span of a 2" x 10" Southern Pine #2 floor joist at 16" on center spacing for a residential area?

1. 12'-0"

2. 14'-0"

3. 16'-0"

4. 18'-0"

The correct answer is: 14'-0"

The maximum span for a 2" x 10" Southern Pine #2 floor joist spaced at 16 inches on center in a residential area is indeed 14 feet. This value is derived from the National Design Specification (NDS) for Wood Construction, which offers span tables that account for factors such as the type of wood, the size of the joist, the spacing, and the live and dead loads expected in a residential application. When determining the maximum span, it's important to consider the structural integrity of the floor system. Floor joists must be able to safely support the intended loads without excessive deflection or risk of failure. A span of 14 feet for a 2" x 10" joist is suitable for typical residential loading conditions, allowing for a balance of safety and material efficiency. Using spans longer than specified can lead to problems like sagging, bounce, and even structural failure, emphasizing the importance of adhering to these guidelines to ensure safe and sound construction practices.