ADAAG Manual

Handrails [4.9.4]

Continuous handrails are required along both sides of stairs. A center rail is not specified for wide stairways by ADAAG but may be required by local building or life safety codes.

Shape and Diameter

Use of a handrail requires the formation of a power grip so that hands and fingers can be opposed and the surface of the palm can be in maximum contact with the rail surface. Large sections, particularly those of rectangular design, are not as graspable as smaller circular sections. A gripping surface width between 1¼ to 1½ inches diameter is specified. Also permitted are rails that allow an opposing grip similar to that possible with a circular section of 1¼ to 1½ inches diameter. Standard IPS pipe designated as 1¼ to 1½ inch is acceptable. (Consider a 1¼ inch specification for pipe since a 1½ inch specification may result in an outer diameter close to 2 inches.) The 1½ inch clearance between walls and handrails is an absolute dimension; it provides knuckle clearance while preventing entrapment of the arm for people who lean on rails with their forearm.

Extensions

Extensions at the top provide support before the first step is made. The bottom extension is especially important in providing this support until one is fully vertical. For extensions to provide this support, they must be in line with the direction of travel on the stairs. Extensions are not required in alterations if they project into cross circulation paths. Extensions must be rounded or returned to the walls, floors, or posts. Requirements for protruding objects in 4.4 limit post-mounted overhangs to 12 inches if the leading edge is higher than 27 inches from the floor.