Structural Integrity: All stairs must be kept structurally sound. Don’t forget to examine the basement stairs. Check the area where they meet the floor and where they are attached to the floor joists above.
Stair Width and Clearance: Stairways should have a minimum headroom of 6 feet and 8 inches, and width of 3 feet.
Treads and Risers: The riser of a stair is the height of the step. The tread is the step’s depth. Riser heights and tread depths should be as uniform as possible. All treads should be level and secure. As a guide, stairs in new homes must have a maximum riser height of 7-3/4 inches and a minimum tread depth of 10 inches. The maximum difference in height for risers and depth for treads should not exceed 3/8-inch.
Handrails and Guardrails: You can check a railing’s stability and its fastenings by shaking it vigorously. Handrails are normally required to be 34 to 38 inches above the stair nosing on at least one side of all stairways having three or more risers. Guardrails are required on open sides of stairways and should have intermediate rails that do not allow the passage of a sphere 4 inches in diameter.
Lighting: All interior and exterior stairways should have a means to illuminate the stairs, including landings and treads. Interior stairways should have a light located at each landing, except where a light is installed directly over each stairway section. Public stair and hallway lights in multi-family buildings should be operable from centralized controls.
Smoke Detectors: In addition to having them installed in each bedroom or in hallways adjacent to each bedroom, smoke detectors should be installed above stairways and hallways. They should be located on or near the ceiling, near the heads of stairs, and away from corners. Periodically check the operation of all smoke detectors by pushing their test buttons.