A 30-by-60-inch annealed pane beside a bottom stair landing has its lower edge 22 inches above the landing. It lies 48 inches from the bottom tread nosing within the 60-inch horizontal arc of less than 180 degrees described in 2021 IRC R308.4.7. No protective guard or approved compliant alternative is provided. What is the finding?
- APane area greater than 9 square feet exempts it from every stair-landing rule
- The bottom-landing hazardous-location rule applies, so compliant safety glazing is required
- CThe bottom-landing rule extends only 36 inches horizontally
- DAny adhesive film automatically establishes safety-glazing compliance
Where to look it up
https://codes.iccsafe.org/content/IRC2021P1/chapter-3-building-planning
Why B is correct
The pane area is 30 × 60 / 144 = 12.5 square feet. R308.4.3’s large-pane test does not apply on these facts because its below-18-inch bottom-edge condition is absent. Independently, R308.4.7 does apply: 22 inches is below 36 inches, and the pane is within the specified 60-inch arc without the guard exception. The resulting safety glazing must satisfy the applicable impact and identification requirements in R308.1 and R308.3. Do not assume an arbitrary film establishes compliance, that every unmarked pane is necessarily annealed, or that replacing a complete sash is the only possible approved remedy. Source: https://codes.iccsafe.org/content/IRC2021P1/chapter-3-building-planning