Unrestricted Construction Supervisor License (CSL) Practice Exam 2026 - Free CSL License Practice Questions and Study Guide

When determining the minimum net thickness of floor sheathing with a joist spacing of 16 inches, it is important to consider both the structural requirements and the standards established by building codes. Sheathing acts as a critical component in distributing loads and providing stability to the floor system.

For joist spacing of 16 inches, the appropriate thickness for plywood or oriented strand board (OSB) sheathing is typically 5/8 inch. This thickness ensures that the sheathing has adequate strength and stiffness to prevent deflection under load. It also aligns with building code recommendations which often specify minimum thicknesses based on spacing to guarantee the safety and durability of the floor.

The other thicknesses listed typically do not meet the required specifications for this application when joist spacing is 16 inches, making the 5/8-inch thickness the correct choice.