When backfill is more than 12 inches above the interior grade of the crawl space, what must the thickness of plywood sheathing be when the backfill height is 36 inches?

When determining the required thickness of plywood sheathing for backfill heights in construction settings, it’s important to consider both load-bearing capacity and safety. In this scenario, when the backfill exceeds 12 inches above the interior grade of the crawl space and reaches 36 inches, the specific requirement of thickness becomes critical for ensuring that the sheathing can withstand the pressure exerted by the backfill.

The correct answer points to a plywood thickness of 15/32 inch. This standard thickness is sufficiently robust to offer support against the lateral loads resulting from the weight and pressure of the backfill material at that height. Generally, codes and best practices dictate specific thicknesses for sheathing based on loading conditions. In this case, for 36 inches of backfill, 15/32 inch plywood is chosen as it balances adequate strength without being excessively cumbersome.

This thickness is often recommended in building codes for scenarios with significant backfill heights, as it has proven effective in previous applications. It demonstrates that while options like 1/4 inch may be insufficient to handle such load, thicker materials such as 1/2 inch or 5/8 inch may be unnecessarily heavy and costly for the requirement at hand. Thus, 15/32 inch plywood is