Stair Details
(a) Width -
Stairs shall measure at least 36 inches in width. Handrails and associated trim may project no more than 4 ½" into the required width at each side of the stairs.
(b) Headroom -
Stairs shall be provided with a minimum headroom clearance of 76 inches. The clearance shall be measured vertically from a line parallel to the nosing of the treads to the ceiling or soffit directly above that line.
(c) Treads and risers
- Except for spiral stairs and winders, risers may not exceed 8 inches in height measured vertically from tread to tread. Treads shall be at least 9 inches wide measured horizontally from nosing to nosing.
- Within individual stairways, tread widths and riser heights may vary in uniformity by a maximum of 3/8 inches. Variations in uniformity may not cause either dimension in subd. 1 to be exceeded.
(d) Winders -
Winder steps may be used provided the length of the tread is at least 36 inches and the width of the tread is at least 7 inches measured at a point 12 inches from the narrow end.
(e) Spiral Stairs -
Spiral stairs may be used as exit stairs.
- The tread shall measure at least 26 inches from the outer edge of the supporting column to the inner edge of the handrail and at least 7 inches in width from nosing ot nosing at a point 12 inches from the narrow end of the tread.
- The riser height shall be uniform and may not exceed 9 ½ inches.
