SPS 321.04(2)(b)2.
2. Risers in spiral staircases may not exceed 9.5 inches in height measured vertically from tread to tread.
SPS 321.04(2)(c)1.1. `Rectangular treads.' Rectangular treads shall have minimum tread depth of 9 inches measured horizontally from nosing to nosing.
SPS 321.04(2)(c)2.
2. `Spiral staircase treads.' Spiral staircase treads shall have a minimum tread depth of 7 inches from nosing to nosing measured at a point 12 inches from the outer edge of the center column.
SPS 321.04(2)(c)3.
3. `Winder treads in series.' Two or more winder treads may be placed immediately adjacent to each other anywhere in a stairway provided both of the following conditions are met:
SPS 321.04(2)(c)3.a.
a. The winder treads shall have a minimum tread depth of 7 inches measured at a point 12 inches from the narrow end of the tread.
SPS 321.04(2)(c)3.b.
b. The depth of the immediately adjoining winder treads shall be equal at a point 12 inches from the narrow end of the tread or inside face of spindles or balusters.
SPS 321.04(2)(c)4.a.a. An individual winder tread may be placed between rectangular treads or at the end of a flight of rectangular treads provided the tread depth is at least 9 inches, when measured at a distance of 12 inches from the narrow end of the tread or from the inside face of the wall.
SPS 321.04(2)(d)1.1. Stairways shall be provided with a minimum headroom clearance of 76 inches measured vertically from a line parallel to the nosing of the treads to the ceiling, soffit or any overhead obstruction directly above that line.
SPS 321.04(2)(d)2.
2. The headroom clearance shall be maintained over an intermediate landing.
SPS 321.04(2)(d)3.
3. The headroom clearance shall be maintained over a landing that is at the top or bottom of a stairway for a minimum distance of 36 inches in the direction of travel of the stairway.
SPS 321.04(2)(e)1.1. Within a stairway flight, the greatest tread depth may not exceed the smallest tread depth by more than
3/8 inch and the greatest riser height may not exceed the smallest riser height by more than
3/8 inch.
SPS 321.04(2)(e)2.
2. The allowed variation in uniformity under subd.
1. may not be used to exceed the maximum riser height under par.
(b) or to decrease the minimum tread depth under par.
(c).
SPS 321.04(2)(f)
(f) Open risers. Stairways with open risers shall be constructed to prevent the through-passage of a sphere with a diameter of 4 inches or larger between any 2 adjacent treads.
SPS 321.04(2)(g)
(g)
Walking surface. The walking surface of stair treads and landings shall be a planar surface that is free of lips or protrusions that could present a tripping hazard.
SPS 321.04(3)(a)1.1. A flight of stairs with more than 3 risers shall be provided with at least one handrail for the full length of the flight.
SPS 321.04(3)(a)2.
2. Guards shall be provided on all open sides of stairs consisting of more than 3 risers and on all open sides of areas that are elevated more than 24 inches above the floor or exterior grade.
SPS 321.04 Note
Note: A handrail provided at 30 to 38 inches above the tread nosing meets the height requirement for a guard on a stairway.
SPS 321.04(3)(a)3.a.a. Except as provided in subd.
3. b., guards shall be constructed to prevent the through-passage of a sphere with a diameter of 4 3/8 inches, when applying a force of 4 pounds.
SPS 321.04(3)(a)3.b.
b. The triangular area formed by the tread, riser and bottom rail shall have an opening size that prevents the through-passage of a sphere with a diameter of 6 inches, when applying a force of 4 pounds.
SPS 321.04(3)(a)3.c.
c. Rope, cable, or similar materials used in guard infill shall be strung with maximum openings of 3 1/2 inches with vertical supports a maximum of 4 feet apart.
SPS 321.04 Note
Note: In some cases, the vertical supports could be simple cable stays that offer vertical support to the rope or cable span. Structural posts must be supplied to provide the rail with the minimum 200 pound load resistance, as well as to resist the tensile loads exerted by the tightened rope or cable.
SPS 321.04(3)(a)4.a.a. Handrails and guards shall be designed and constructed to withstand a 200 pound load applied in any direction.
SPS 321.04(3)(a)4.b.
b. Handrail or guard infill components, balusters and panel fillers shall withstand a horizontally applied perpendicular load of 50 pounds on any one-foot-square area.
SPS 321.04(3)(a)5.
5. Exterior handrails and guards shall be constructed of metal, decay resistant or pressure-treated wood, or shall be protected from the weather.
SPS 321.04(3)(b)1.a.a. Handrails shall be located at least 30 inches, but no more than 38 inches above the nosing of the treads, except as provided in subds.
1. b. to
d. Measurement shall be taken from the hard structural surface beneath any finish material to the top of the rail. Variations in uniformity are allowed only when a rail contacts a wall or newel post or where a turnout or volute is provided at the bottom tread.
SPS 321.04(3)(b)1.b.
b. A volute, turnout, or starting easing that does not comply with subd.
1. a. may extend over the lowest tread.
SPS 321.04(3)(b)1.d.
d. Where handrail fittings or bendings are used to provide a continuous transition between flights, or at winder treads, or from a handrail to a guard, or at the start of a flight, the height at the fittings or bendings may exceed 38 inches.
SPS 321.04(3)(b)2.
2. `Clearance.' The clearance between a handrail and the wall surface shall be at least 1 1/2 inches.
SPS 321.04(3)(b)3.a.a. Except as provided under subd.
3. b., the required handrail on winder stairs shall be placed on the side where the treads are wider.
SPS 321.04(3)(b)3.b.
b. Where all winder treads in a flight have a depth of at least 9 inches from nosing to nosing measured at a point 12 inches from the narrow end of the tread, the required handrail may be located on either side of the stairway.
SPS 321.04(3)(b)4.
4. `Projection.' Handrails and associated trim may project into the required width of stairs and landings a maximum of 4 1/2 inches on each side.
SPS 321.04(3)(b)5.
5. `Size and configuration.' Handrails shall be symmetrical about the vertical centerline to allow for equal wraparound of the thumb and fingers.
SPS 321.04(3)(b)5.a.
a. Handrails with a round or truncated round cross sectional gripping surface shall have a maximum whole diameter of 2 inches.
SPS 321.04(3)(b)5.b.
b. Handrails with a rectangular cross sectional gripping surface shall have a maximum perimeter of 6 1/4 inches with a maximum cross sectional dimension of 2 7/8 inches.
SPS 321.04(3)(b)5.c.
c. Handrails with other cross sections shall have a maximum cross sectional dimension of the gripping surface of 2 7/8 inches with a maximum linear gripping surface measurement of 6 1/4 inches and a minimum linear gripping surface of 4 inches.
SPS 321.04 Note
Note: See ch.
SPS 325 Appendix A for further information on handrail measurement.
SPS 321.04(3)(b)6.
6. `Continuity.' Handrails shall be continuous for the entire length of the stairs except in any one of the following cases:
SPS 321.04(3)(b)6.c.
c. A handrail may terminate at an intermediate wall provided the lower end of the upper rail is returned to the wall or provided with a flared end, the horizontal offset between the 2 rails is no more than 12 inches measured from the center of the rails, and both the upper and lower rails can be reached from the same tread without taking a step.
SPS 321.04(3)(c)1.a.a. All openings between floors, and open sides of landings, platforms, balconies or porches that are more than 24 inches above grade or a floor shall be protected with guards.
SPS 321.04(3)(c)1.b.
b. The requirements under subd.
1. a. apply where insect screens are the only means of enclosure or protection for a surface that is more than 24 inches above grade or a floor.
SPS 321.04(3)(c)1.c.
c. For exterior applications, the 24 inch vertical measurement shall be taken from the lowest point within 3 feet horizontally from the edge of the deck, landing, porch or similar structure.
SPS 321.04(3)(c)1.d.
d. This paragraph does not apply to window wells, egress wells, and retaining walls.
SPS 321.04(3)(c)2.
2. `Height.' Guards shall extend to at least 36 inches above the floor or to the underside of a stair handrail complying with s.
SPS 321.04 (3) (b). Measurement shall be taken from the hard structural surface beneath any finish material to the top of the guard.
SPS 321.04(3)(c)3.
3. `Opening size.' Guards shall be constructed to prevent the through-passage of a sphere with a diameter of 4 3/8 inches, when applying a force of 4 pounds.
SPS 321.04(4)(a)1.1. A level intermediate landing shall be provided in any stairway with a height of 12 feet or more.
SPS 321.04(4)(a)2.
2. Intermediate landings that connect 2 or more straight flights of stairs, or 2 flights of stairs at a right angle, shall be at least as wide as the treads and shall measure at least 36 inches in the direction of travel.
SPS 321.04(4)(a)3.
3. Curved or irregular landing shall have a radius of at least 36 inches.
SPS 321.04(4)(a)4.
4. Curved or irregular landings shall have a minimum straight line measurement of 26 inches between the nosing of the 2 connecting treads measured at a point 18 inches from the narrow end of the landing measured along the nosing of the 2 treads.
SPS 321.04(4)(b)
(b) Landings at the top and base of stairs. A level landing shall be provided at the top and base of every stairs except as provided in par.
(d). The landing shall be at least as wide as the treads and shall measure at least 3 feet in the direction of travel.
SPS 321.04(4)(c)
(c) Doors at landings. Except as provided in subds.
1. to
3. and par.
(d), level landings shall be provided on each side of any door located at the top or base of a stair, regardless of the direction of swing. In the following exceptions, a stairway between a dwelling and an attached garage, carport or porch is considered to be an interior stair:
SPS 321.04(4)(c)1.
1. A landing is not required between the door and the top of interior stairs if the door does not swing over the stairs.
SPS 321.04(4)(c)2.
2. A landing is not required between the door and the top of an interior stairs of 1 or 2 risers regardless of the direction of swing.
SPS 321.04(4)(c)3.
3. A landing is not required between a sliding glass door or an in-swinging glass door and the top of an exterior stairway of 3 or fewer risers.
SPS 321.04(4)(d)1.1. The exterior landing, platform, or sidewalk at an exterior doorway shall be located a maximum of 8 inches below the interior floor elevation, be sloped away from the doorway at a minimal rate that ensures drainage, and have a length of at least 36 inches in the direction of travel out of the dwelling.
SPS 321.04(4)(d)2.
2. The landing at the base of an exterior stair shall be sloped away from the stair at a minimal rate that ensures drainage.
SPS 321.04 History
History: Cr.
Register, November, 1979, No. 287, eff. 6-1-80; r. and recr.
Register, February, 1985, No. 350, eff. 3-1-85; am. (intro.), r. and recr. (1) (c), renum. (3) (f) to Comm 21.042,
Register, January, 1989, No. 397, eff. 2-1-89; r. and recr. (intro.) and (3) (c), am. (1) (a), (2) (a) and (c) 2. and (3) (a), cr. (2) (c) 6., March, 1992, No. 435, eff. 4-1-92; r. and recr.,
Register, November, 1995, No. 479, eff. 12-1-95; am. (1) (c) 1. and (d), renum. (2) (intro.) to (b) to be (2) (a) to (c) and am. (a), r. (2) (b) (intro.),
Register, February, 1997, No. 494, eff. 3-1-97; reprinted to restore dropped copy,
Register, March, 1997, No. 495; r. (1), renum. (intro.) to be (1) and am., renum. (2) and (3) to be (3) and (4), cr. (2) and r. and recr. (4) (a),
Register, March, 2001, No. 543, eff. 4-1-01;
CR 02-077: am. (2) (b) 1., (e) 1. and (3) (a), cr. (2) (f) and (3) (c) 3., r. and recr. (3) (b) 3., renum. (4) (c) to be (4) (c) 1. (intro.), a. to c. and 2. and am. (4) (c) 1. (intro.) and 2.
Register May 2003, No. 569, eff. 8-1-03;
CR 03-097: am. (2) (f), (3) (a) 3., and (c) 3.
Register November 2004 No. 587, eff. 1-1-05;
CR 08-043: r. and recr. (1), am. (2) (c) 2., 3. b. and (e) 1., cr. (2) (c) 3. c., 4. c., (g), (3) (a) 3. c., 4. b., c., (c) 1. b. and c., renum. (3) (a) 4. and (c) 1. to be (3) (a) 4. a. and (c) 1. a.
Register March 2009 No. 639, eff. 4-1-09;
CR 15-041: am. (1) (a) 2., (2) (a) 1., (c) 4. a., b., (3) (title), (a) 1. to 5., renum. (3) (b) 1. to (3) (b) 1. a. and am., cr. (3) (b) 1. b. to d., am. (3) (b) 3. a., b., (c) (title), 1. a., cr. (3) (c) 1. d., am. (3) (c) 2., 3., (4) (a) 2., (b), renum. (4) (c) 1. to (c) and am. (intro.) and 3., renum. (4) (c) 2. to (4) (d) 1. and am., cr. (4) (d) (title), 2.
Register December 2015 No. 720, eff. 1-1-16;
CR 15-041: am. (4) (c) 3. (omitted
Register December 2015 No. 720)
Register January 2016 No. 721.
SPS 321.042
SPS 321.042 Ladders. Ladders which are used as part of a required exit shall conform to this section.
SPS 321.042(1)
(1)
Design load. Ladders shall be designed to withstand loads of at least 200 pounds.
SPS 321.042(2)(a)(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.
-
See PDF for table 
SPS 321.042(2)(b)
(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 1 1/2 inch for wood ladders. All rungs shall be uniform in dimension.
SPS 321.042(3)
(3)
Risers. Risers shall be uniform in height and shall conform with Table 321.042.
SPS 321.042(4)
(4)
Width. The width of the ladder shall be a minimum of 20 inches wide and a maximum of 30 inches wide.
SPS 321.042(5)(a)(a) Handrails shall be required for ladders with pitches less than 65
°.
SPS 321.042(5)(b)
(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.
