Inspecting Spiral Staircases

Inspecting Spiral Staircases

Many staircases are poorly built. In addition to tripping hazards, many times they are not built to code. We know the requirements for “traditional” staircases. When inspecting a spiral staircase recently, my client and I both tripped when descending. My client asked me if the spiral staircase was built “up to code” I had to get my tape measure out. The requirements for rectangular treads differ from winder treads which also are different from a spiral staircase. All staircases with more than two treads should have a railing. A light and switch should be at the top and bottom of every staircase. The difference in height between any two risers should not exceed 3/8”. Riser boards should be used and open risers should not allow a 4” diameter sphere to pass. The minimum stairway width is 36” measured from the handrail. Minimum stairway headroom is 80”.  So what are the requirements for a properly built spiral staircase?   Spiral Stairway Requirements:  All treads should be identical The minimum tread depth is 7 ½” measured 12 inches from the narrowest side The maximum riser height is 9 ½” The minimum staircase width is 26” A stairway should not be more than 12 feet in height without a landing A landing should be as wide as the widest part of the staircase. If a door is present, the landing should be at least 36” X 36 “ The spiral staircase should be properly attached with minimal movement It is recommended that another rectangular 36” staircase is present in addition to a spiral staircase