Laserfiche WebLink
R407.1 General. Stairways shall comply with R407. <br />R407.2 Treads and Risers. All steps on a flight of stairs shall have uniform riser heights <br />and uniform tread depths. Risers shall be 100 mm (4 in) high minimum and 180 mm (7 <br />in) high maximum. Treads shall be 28 cm (11 in) deep minimum. <br />R407.3 Open Risers. Open risers are not permitted. <br />R407.4 Tread Surface. Stairway treads shall comply with R301.5. Stairway treads shall <br />have a 51 mm (2 in) minimum wide strip that contrasts visually with the tread and riser. <br />The strip shall be located at the front of each tread and run the full width of the tread. <br />R407.5 Nosings. The radius of curvature at the leading edge of the tread shall be 13 mm <br />(0.5 inch) maximum. Nosings that project beyond risers shall have the underside of the <br />leading edge curved or beveled. Risers shall be permitted to slope under the tread at an <br />angle of 30 degrees maximum from vertical. The permitted projection of the nosing shall <br />extend 38 mm (1.5 in) maximum over the tread below. <br />R407.6 Handrails. Stairs shall have handrails complying with R408. <br />R408 Handrails <br />R408.1 General. Handrails provided along walking surfaces complying with R301, <br />required at ramps complying with R406, and required at stairs complying with R407 shall <br />comply with R408. <br />Advisory R408.1 General. Handrails are required on ramp runs with a rise greater than <br />150 mm (6 in) and on certain stairways. Handrails are not required on walking surfaces <br />with running slopes less than 5 percent. However, if handrails are provided on walking <br />surfaces with running slopes less than 5 percent, they must comply with R408. Sections <br />R408.2, R408.3, and R408.10 do not apply to handrails provided on walking surfaces <br />with running slopes less than 5 percent as those sections only reference requirements for <br />ramps and stairs. <br />R408.2 Where Required. Handrails shall be provided on both sides of stairs and ramps. <br />R408.3 Continuity. Handrails shall be continuous within the full length of each stair <br />flight or ramp run. Inside handrails on switchback or dogleg stairs and ramps shall be <br />continuous between flights or runs. <br />R408.4 Height. Top of gripping surfaces of handrails shall be 87 cm mm (34 in) <br />minimum and 97 cm (38 in) maximum vertically above walking surfaces, stair nosings, <br />and ramp surfaces. Handrails shall be at a consistent height above walking surfaces, stair <br />nosings, and ramp surfaces. <br />52 <br />