Pennsylvania Code › Title 34 - LABOR AND INDUSTRY › Part I - Department of Labor and Industry › Chapter 50 - GENERAL REQUIREMENTS-BUILDINGS › MEANS OF EGRESS › Section 50.25 - Stair towers

Current through Register Vol. 54, No. 28, July 13, 2024
(a) A stair
				  tower shall be a stairway which is separated from all floors or areas of the
				  building. Stair towers shall lead directly to grade by an exit
				  discharge.
(b) Stair towers shall
				  be Class A or Class B types in accordance with the following table:
Class A
								Stair
Class B Stair
Minimum clear width in inches
40"
36"
Maximum height of riser
7 1/2"
8"
Minimum width of tread
10"
9"
Maximum angle of stairs in degrees
33°
40°
Required handrails (Each handrail is allowed to
								project 3" without decreasing minimumclear width)
Both sides
One side under 40" in width, both sides 40" or more in width
Maximum vertical distances between
								landings
9'
12'
(c)
				  The minimum width of landings shall be the same width as the stairs they serve.
				  Intermediate landings on straight run stairs shall have a minimum length of 3
				  feet.
(d) The narrowest width in a
				  stairway or landing serving a stairway shall determine the units of width for
				  the entire stairway.
(e) There
				  shall be no variation in the width of treads or the height of risers in any
				  flight. Variation in height of risers in adjacent flights shall not exceed 1/4
				  inch. All treads less than 10 inches, as measured horizontally between the face
				  of risers, shall have an effective projection of approximately 1 inch beyond
				  the face of the riser below.
(f)
				  Where material of stair treads and landings is such as to present a danger of
				  slipping, nonskid material shall be applied.
(g) No arrangement of treads known as winders
				  shall be permitted in required exit stairways.
(h) Stairways, landings, balconies, open
				  sided floors, and the like shall have well-secured handrails. The clear
				  distance between handrail and wall or other obstruction shall be not less than
				  1 1/2 inches. Longitudinal rails or balusters or both shall be provided.
				  Balusters shall be spaced not more than 6 inches apart. Longitudinal rails
				  shall not exceed 6 inches measured at right angles to the rails. The lowest
				  rail shall be measured vertically from the tread nosing.
(i) Handrails on stairs shall be not less
				  than 30 inches nor more than 34 inches above the upper surface of the tread,
				  measured vertically to the top of the rail, from a point on the tread 1 inch
				  back from the leading edge.
(j)
				  Handrails shall be provided on any stair landing, balcony, ramp, aisle, and the
				  like located along the edge of open sided floors or mezzanines to prevent falls
				  over the open side. Railings protecting open sides of landings, balconies,
				  mezzanines, and the like shall be at least 42 inches high.
(k) Storage or obstructions of any kind shall
				  not be permitted in stair towers.
(l) A door opening into a stair tower shall
				  at no point in its swing reduce the required units of width of the stair or
				  landing.
(m) Every door to a
				  stairway shall open onto a landing at least as wide as the stairs.
(n) Doors and frames used in connection with
				  stair towers shall be of approved label and be of substantial construction,
				  installed in a workmanlike manner, fitted with reliable hardware of approved
				  label and shall be of the side hinged, swing type.
(o) Stair tower doors shall swing with the
				  exit travel.
(p) Stair tower doors
				  shall be provided with fire exit hardware. Exterior doors from stair towers may
				  have panic hardware instead of fire exit hardware. No lock or other device
				  which prevents egress shall be permitted on the doors during any period of
				  occupancy.
(q) Stair tower doors
				  shall be a minimum of 32 inches in width. Doors used in connection with stair
				  towers shall be a minimum of 6 feet, 8 inches in height.
(r) Outside stairs shall be considered an
				  exit when they meet the following conditions:
(1) Outside stairs shall meet the conditions
				  listed in subsections (b)-(d), (f)-(j) and (l)-(q).
(2) Outside stairs shall only serve as an
				  exit for floors three or fewer stories above grade.
(3) Outside stairs shall be accessible and
				  unobstructed at all times of occupancy.
(4) Outside stairs shall be of substantial
				  construction and installed in a workmanlike manner. Combustible construction
				  may be used when floor panels are permitted to be combustible construction in
				  the construction tables. Wood stringers shall be a minimum size of 2 inches by
				  10 inches stock material when treads are butt nailed or a minimum of 2 inches
				  by 12 inches stock material when the stringers are sawed to accommodate the
				  treads.
(5) Handrails shall be
				  provided on both sides of outside stairs except that a handrail is not required
				  along a solid wall when the dimensions from the exterior handrail to the solid
				  wall is 36 inches or less.
(6) The
				  building exterior wall shall be fire rated in accordance with the rating
				  required for exterior walls in §
											50.11 (relating to construction
				  tables).
(7) All doors opening onto
				  the outside stair and door assemblies located within 10 feet of any portion of
				  the outside stair shall have a fire rating the same as the rating required for
				  the exterior wall except that a door located at the top of the outside stair
				  need not be fire rated. All other openings within 10 feet of either side or
				  below the outside stair shall be glazed with 1/4 inch wire glass in steel
				  frames.