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 dwelling is located in a seismic design category D2 area. What is the minimum nominal thickness required for wood structural panel wall sheathing used for shear walls in this dwelling?
- A7/16 inch
- B3/8 inch
- C5/8 inch
- D1/2 inch
Show answer & explanationAnswer & explanation
Correct answer: A. 7/16 inch
For dwellings in Seismic Design Category D2, the IRC requires a minimum nominal thickness of 7/16 inch for wood structural panel wall sheathing when used for shear walls. This ensures adequate resistance to seismic forces.
Why the other options are wrong
- B. 3/8 inch sheathing is generally not sufficient for shear walls in higher seismic categories.
- C. 5/8 inch sheathing is typically used for roofs or floors requiring higher strength, or for walls in very high load conditions, but exceeds the minimum for this scenario.
- D. 1/2 inch sheathing is also acceptable but not the minimum required.
Shear Wall Sheathing Thickness (Seismic D2)
In areas with high seismic risk (Seismic Design Category D2), wood structural panel wall sheathing used for shear walls must meet a minimum thickness to provide sufficient lateral force resistance.
- Applies to shear walls resisting seismic forces.
- Thickness depends on seismic design category.
- Ensures structural integrity during earthquakes.
Memory trick: For D2 seismic, 'seven-sixteenths' is the wall's strong shield.