Residential Building Inspector B1Wall Construction and Wall CoveringsHard
A builder is installing a continuous wood structural panel shear wall in a detached garage. The wall segment is 10 feet long and 8 feet high. If the required shear capacity for this segment is 300 pounds per linear foot, what is the minimum nominal thickness of wood structural panel required, assuming 16d common nails at 6 inches on center at all panel edges?
- A15/32 inch plywood
- B7/16 inch OSB
- C5/8 inch plywood
- D1/2 inch OSB
Show answer & explanationAnswer & explanation
Correct answer: B. 7/16 inch OSB
Consulting IRC Table R602.10.4(1) for wood structural panel shear walls, with 16d common nails at 6 inches o.c. at all panel edges, a 7/16-inch OSB panel provides a shear value of 350 plf (pounds per linear foot) for an 8-foot high wall. This exceeds the required 300 plf. Thinner panels or wider spacing would not meet the requirement.
Why the other options are wrong
- A. 15/32 inch plywood with 16d nails at 6" o.c. provides 390 plf capacity, which also meets the requirement but is thicker than necessary.
- C. 5/8 inch plywood provides significantly higher capacity (e.g., 520 plf) and is overkill for this specific shear requirement.
- D. 1/2 inch OSB (often specified as 15/32 or 7/16 actual) would also meet the requirement, but 7/16 is explicitly listed and sufficient.
Shear Wall Capacity Selection
Selecting the correct wood structural panel and fastening schedule for a shear wall involves matching the required shear capacity (plf) with values from IRC tables.
- Capacity depends on panel thickness, fastener type, and fastener spacing.
- Table R602.10.4(1) provides shear values for common configurations.
- Always select a combination that meets or exceeds the required plf.
Memory trick: Match the wall's 'muscle' (capacity) to the 'weight' it needs to hold, using the code table.