1123A.6 Interior Stairway Handrails
Handrail gripping surfaces shall comply with this section, or the shape shall provide equivalent gripping surface.
- Circular cross section. The handrail gripping surfaces with a circular cross section shall not be less than 11/4 inches (31.75 mm) nor more than 2 inches (50.8 mm) in cross-sectional dimension.
- Noncircular cross section. Handrail gripping surfaces with a noncircular cross section shall have a perimeter dimension of 4 inches (102 mm) minimum and 61/4 inches (159 mm) maximum, and a cross-section dimension of 21/4 inches (57 mm) maximum.
At the top of stair flights, handrails shall extend a minimum of 12 inches (305 mm) horizontally above landings, beginning directly above the first riser nosing. Extensions shall return to a wall, guard, or the walking surface, or shall be continuous to the handrail of an adjacent stair flight.
At the bottom of stair flights, handrails shall extend at the slope of the stair flight for a distance equal to one tread depth beyond the last riser nosing. Such extension shall continue with 12 inches (305 mm) minimum horizontal extension, shall be continuous to the handrail of an adjacent stair flight, or shall return to a wall, guard, or the walking surface. Handrail horizontal extensions shall be in the same direction as the stair flights. (See Figures 11A-6A and 11A-6E.)
Handrails may be located in a recess if the recess is a maximum of 3 inches (76.2 mm) deep and extends at least 18 inches (457 mm) above the top of the rail. Any wall or other surface adjacent to the handrail shall be free of sharp or abrasive elements. (See Figure 11A-6B.)
Handrail gripping surfaces shall be continuous along their length, and shall not be obstructed along their tops or sides. The bottoms of handrail gripping surfaces shall not be obstructed for more than 20 percent of their length. When provided, horizontal projections shall occur 11/2 inches (38 mm) minimum below the bottom of the handrail gripping surface. The distance between horizontal projections and the bottom of the gripping surface shall be permitted to be reduced by 1/8 inch (3.2 mm) for each 1/2 inch (12.7 mm) of additional handrail perimeter dimension that exceeds 4 inches (102 mm).