Question

Triangular openings at the open side of a stair, formed by a riser, tread, and bottom rail of the required guard shall not allow passage of a ______, in diameter, sphere?

1) 1-inch
2) 2-inch
3) 3-inch
4) 4-inch

Answer 1

The triangular openings at the side of a stair, as formed by a riser, tread, and bottom rail of the guard must not allow a 4-inch diameter sphere to pass through, which is a safety measure to protect children.

Step-by-step explanation:

The question pertains to the safety standards for stairway construction, specifically referencing the size of the diameter of a sphere that should not be able to pass through the openings in a stair guardrail system. According to most building codes, including those set by the International Residential Code (IRC) and International Building Code (IBC), the openings at the side of a stair should not allow the passage of a 4-inch diameter sphere. This rule is designed to prevent small children from slipping through the gaps and ensures the guardrails provide adequate safety.