Commercial Building Inspector B2Structural SystemsMedium
A building inspector is reviewing the plans for a new single-story commercial building with wood-framed shear walls. The design specifies 7/16-inch oriented strand board (OSB) sheathing with 8d common nails spaced at 6 inches on center at all panel edges. What is the maximum allowable aspect ratio (height-to-width) for a shear wall segment with this sheathing and nailing schedule, assuming a single row of nails at the boundaries according to IBC 2021?
- A4.5:1
- B5:1
- C3.5:1
- D2:1
Show answer & explanationAnswer & explanation
Correct answer: C. 3.5:1
According to IBC 2021, Table 2306.4.1(1), for wood structural panel shear walls with 7/16-inch OSB and 8d common nails at 6 inches on center, the maximum aspect ratio for a single shear wall segment is 3.5:1. This table is used for determining nominal unit shear capacities and associated limitations.
Why the other options are wrong
- A. This ratio typically applies to walls with more robust sheathing or closer nailing schedules, or specific hold-down requirements.
- B. This aspect ratio is generally too high for standard wood structural panel shear walls and would likely require specialized design or materials.
- D. This is a common aspect ratio but not the maximum for this specific sheathing and nailing condition.
Wood Shear Wall Aspect Ratio
The ratio of a wood structural panel shear wall segment's height to its width, limited by code to ensure stable and predictable performance under lateral loads.
- Limits vary based on sheathing material, thickness, and nailing schedule.
- Higher ratios can lead to instability and reduced shear capacity.
- Found in IBC tables, typically Section 2306.4.
Memory trick: Wood Walls need 'Ratios' to Resist 'Racking' (lateral forces).