Pennsylvania Code › Title 34 - LABOR AND INDUSTRY › Part I - Department of Labor and Industry › Chapter 21 - LADDERS › CONSTRUCTION SPECIFICATIONS › Section 21.32 - Side rails

Current through Register Vol. 54, No. 28, July 13, 2024
(a) Unless
				  otherwise specified in subsection (c) or other provisions of this chapter, wood
				  side rails for all ladders shall have a minimum dressed cross section of the
				  following dimensions:
Full working length of ladder
								(feet)
Dimension of side rails at
								center
Thickness
								(inches)
Depth (inches)
Up to and including
								19
1-3/8
2-3/4
Over 19, up to and including
								30
1-3/8
2-3/4
Over 30, up to and including
								38
1-3/8
3
Over 38, up to and including
								42
1-3/8
3-1/2
Over 42, up to and including
								45
1-1/2
2-1/2
Over 45, up to and including
								52
1-5/8
3-3/4
Over 52, up to and including
								55
1-3/4
3-3/4
(b)
				  The dimensions of subsection (a) are based upon a 7/8 inch mortise, 1/8 inch
				  gain, or equivalent for step attachments. Where the strength of side rails is
				  reduced more than this by the step attachments or where it is desired to use a
				  rail section, either dimension of which is less than that specified in
				  subsection (a), the rail section shall develop an actual working stress for the
				  wood listed in §
										21.63 (relating to group three
				  woods), not exceeding 1,600 pounds per square inch when computed by the
				  following formula applying to rectangular sections:
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where
P = pounds, which is the normal component on each rail of a
					 load of 200 pounds at the center of the ladder, equally distributed between the
					 rails, when the foot of the ladder is moved out of the perpendicular by 1/4 of
					 its length.
W = weight of ladder, in pounds.
L = length of ladder, in inches.
B = net thickness of each side rail, in inches (deducting
					 depth of gain, if any, for flat treads).
D = depth of side rail, in inches.
d = diameter of hole drilled for rung (d3
						 shall be taken as not less than 0.67, regardless of the method
					 of step fastening used).
(c)
				  Wood side rails of ladders having cleat steps shall be not less than 3/8 inch
				  greater in thickness and 1/2 inch greater in depth than is specified under
				  subsection (a) of this section, but no such ladder shall be less than 1 5/8
				  inches thick and 3 5/8 inches in depth (2 by 4 inches nominal).
(d) Metal side rails when made of mild steel
				  or wrought iron shall be not less than 9/16 of a square inch in cross section
				  for lengths 12 feet and under, and not less than 3/4 of a square inch in cross
				  section for lengths over 12 feet with a minimum thickness not less than 3/8
				  inch. These dimensions are based upon the removal of not more than 1/2 inch of
				  material for the attachment of the steps. When more material is removed from
				  the side rails for step attachments or when side rails are made of other metal
				  or shapes, they shall have the same strength.
(e) Except as otherwise provided in this
				  chapter, wood side rails shall not be spliced.
This section cited in 34 Pa. Code §
												21.21 (relating to wood side
						rails); 34 Pa. Code §
												21.34 (relating to fixed ladders);
						34 Pa. Code §
												21.35 (relating to single or
						straight ladders); 34 Pa. Code §
												21.36 (relating to extension
						ladders); and 34 Pa. Code §
												21.40 (relating to
						stepladders).