How many risers on a set of stairs require a handrail?

• A. Two risers
• B. Four risers
• C. Six risers
• D. Eight risers

Answer: (B)

A handrail is required on a stair flight once it has four or more risers. A riser is the vertical part of a step, and a flight is the set of steps between landings. When there are four or more risers, the stairs reach a length where additional support is needed for safety, so a handrail must be provided (at least on one side). Stairs with three or fewer risers don’t meet this threshold, so a handrail isn’t required by this rule. Therefore, the number of risers that triggers the handrail requirement is four. Note that wider stairs may demand handrails on both sides, but the minimum trigger is four risers.