Which factor is used to determine the span rating of wood structural panels?

The span rating of wood structural panels is primarily determined by the thickness of the panel. This is because the thickness directly influences the panel's strength and ability to support loads over a given distance between supports. Thicker panels generally have higher load-bearing capacities, which allows them to span greater distances without sagging or failing. Therefore, when evaluating wood structural panels for use in construction, the thickness is a critical factor, as it helps builders and inspectors assess how far the panels can safely span between supports while maintaining structural integrity.

Even though other factors like density, manufacturing process, and sealing treatments might influence the overall performance and durability of the panels, they do not specifically dictate the span rating as clearly as thickness does. While density may affect strength and weight, it is only one component among many. The manufacturing process and any sealing treatments may contribute to the panel's resilience against moisture or pests, but they play a lesser role in the direct determination of span ratings.