Residential Building Inspector B1Building Planning and Life SafetyMedium
A residential building inspector is performing a rough-in inspection for a new dwelling. The plans indicate that the wall sheathing will be installed directly over the studs. What is the minimum nominal thickness of wood structural panel wall sheathing required to be fastened to studs spaced 24 inches on center?
- A7/16 inch
- B5/8 inch
- C1/2 inch
- D3/8 inch
Show answer & explanationAnswer & explanation
Correct answer: A. 7/16 inch
According to the 2021 IRC, Table R602.10.2(1) Wood Structural Panel Sheathing Requirements for Wind Design, for studs spaced 24 inches on center, the minimum nominal thickness of wood structural panel wall sheathing is 7/16 inch (11.1 mm) when used for shear walls or general sheathing.
Why the other options are wrong
- B. 5/8 inch is typically used for higher performance requirements, such as increased fire resistance or shear values.
- C. 1/2 inch is a common sheathing thickness but not the minimum required for 24-inch on-center studs.
- D. 3/8 inch sheathing is generally only permitted for studs spaced 16 inches on center or less.
Wall Sheathing Thickness
The minimum nominal thickness of wood structural panels required for wall sheathing, determined by stud spacing and design loads.
- Provides structural rigidity and shear resistance.
- Thickness varies with stud spacing.
- Specified in IRC Table R602.10.2(1).
Memory trick: Sheathing thickness depends on stud spread, keeping walls strong and steady.