Section SPS 321.042 - LaddersLadders which are used as part of a required exit shall conform to this section.
(1) DESIGN LOAD. Ladders shall be designed to withstand loads of at least 200 pounds.(2) TREAD OR RUNGS. (a) Minimum tread requirements shall be specified in Table 321.042. Treads less than 9 inches in width shall have open risers. All treads shall be uniform in dimension. Pitch of Ladder Angle to Horizontal (degrees) | Maximum rise (inches) | Minimum Tread (inches) |
41.6 to 48.4 | 8 | 9 |
greater than 48.4 to 55.0 | 9 | 8 |
greater than 55.0 to 61.4 | 10 | 7 |
greater than 61.4 to 67.4 | 11 | 6 |
greater than 67.4 to 71.6 | 12 | 5 |
greater than 71.6 to 75.9 | 12 | 4 |
greater than 75.9 to 80.5 | 12 | 3 |
greater than 80.5 to 90 | 12 | 2 |
(b) Rungs may only be used for ladders with a pitch range of 75° to 90°. Rungs shall be at least 1 inch in diameter for metal ladders and 11/2 inch for wood ladders. All rungs shall be uniform in dimension.(3) RISERS. Risers shall be uniform in height and shall conform with Table 321.042.(4) WIDTH. The width of the ladder shall be a minimum of 20 inches wide and a maximum of 30 inches wide.(5) HANDRAILS. (a) Handrails shall be required for ladders with pitches less than 65°.(b) Handrails shall be located so the top of the handrail is at least 30 inches, but not more than 38 inches, above the nosing of the treads.(c) Open handrails shall be provided with intermediate rails or an ornamental pattern such that a sphere with a diameter of 6 inches or larger cannot pass through.(d) The clearance between the handrail and the wall surface shall be at least 11/2 inches.(e) Handrails shall be designed and constructed to withstand a 200 pound load applied in any direction.(6) CLEARANCES. (a) The ladder shall have a minimum clearance of at least 15 inches on either side of the center of the tread.(b) The edge of the tread nearest to the wall behind the ladder shall be separated from the wall by at least 7 inches.(c) A passage way clearance of at least 30 inches parallel to the slope of a 90° ladder shall be provided. A passage way clearance of at least 36 inches parallel to the slope of a 75° ladder shall be provided. Clearances for intermediate pitches shall vary between these 2 limits in proportion to the slope.(d) For ladders with less than a 75° pitch the vertical clearance above any tread or rung to an overhead obstruction shall be at least 6 feet 4 inches measured from the leading edge of the tread or rung.Wis. Admin. Code Department of Safety and Professional Services SPS 321.042
Renum. from Comm 21.04 (3) (f), cr. (intro.), Register, January, 1989, No. 397, eff. 2-1-89; am. (6) (b), Register, November, 1995, No. 479, eff. 12-1-95; am. (5) (b) and (c), Register, January, 1999, No. 517, eff. 2-1-99; correction in (2) (a), (3) made under s. 13.92(4) (b) 7, Stats., Register December 2011 No. 672.