California Residential Inspector Practice Exam

What is the maximum span for wood structural panels used as roof sheathing with a 40/20 span rating and no edge support when the panel thickness is 5/8 inch?

1. 24 inches

2. 32 inches

3. 36 inches

4. 40 inches

The correct answer is: 32 inches

The correct answer involves understanding the span rating of wood structural panels and how it correlates to roof sheathing applications. A 40/20 span rating indicates that the panel can support a maximum load of 40 pounds per square foot (psf) when used as a roof and 20 psf when used as a wall or floor, assuming no edge support. When applied to the question, a thickness of 5/8 inch for wood structural panels means they can be used in applications that require considerable support, such as in roofing systems. The maximum allowable span for panels used as roof sheathing or decking without any edge support is defined by building codes and standards. In this case, the maximum span for 5/8 inch thick panels with a 40/20 span rating is 32 inches. This figure is based on the performance criteria for the panel in terms of load-bearing capacity and material strength. Structures utilizing panels with this span rating help ensure that roofs are adequately supported while also maintaining structural integrity under various load conditions. Understanding these nuances is essential for making safe and effective choices in residential construction and inspection.