Pennsylvania Code › Title 34 - LABOR AND INDUSTRY › Part I - Department of Labor and Industry › Chapter 21 - LADDERS › CONSTRUCTION SPECIFICATIONS › Section 21.31 - General

Current through Register Vol. 54, No. 28, July 13, 2024
(a)
Sides.
Ladders may have either parallel or spreading straight
				  sides unless otherwise specified in this section. Portable ladders may also
				  have the sides flaring at the base to increase their stability and converging
				  at the top where specific uses warrant.
(b)
Distance.
For ladders
				  exceeding four feet in length, the inside width between side rails shall be not
				  more than 32 inches except for bases flared as permitted in subsection (a) and
				  not less than 10 inches except where rails are converged at the top, in which
				  case this minimum width shall be obtained not more than 4 feet from the top.
				  For ladders not exceeding 4 feet in length the minimum width between side rails
				  shall be not less than 8 inches.
(c)
Spacing.
A uniform step
				  spacing shall be employed. It is recommended that this spacing be 12 inches
				  except where specific uses require shorter spacing in which case it may not be
				  less than 8 inches.
(d)
Fastening.
All holes for wood rungs shall either extend
				  through the side rail or be bored to within 3/16 inch of the outside face of
				  the rail. In the former construction the rungs shall extend through to at least
				  flush with the outside rail surface while in the latter the distance between
				  the end of the rung and the outside face of the rail shall not be greater than
				  5/16 inch.
(e)
Holes.
All holes for wood rungs shall be located on the center line of the
				  wide face of the side rails. The size of holes shall be such as to insure a
				  driving fit for the rung.
(f)
Tenon.
The shoulder of round wood rungs shall be forced firmly
				  against the side rail and the tenon secured in place by a nail or the
				  equivalent to prevent turning. Oval rungs shall be secured in place by two
				  nails or equivalent in each rail.
(g)
Treads.
Wood treads
				  shall be inset in the side rails not less than 1/8 inch, fastened to it by
				  nails or screws, and secured by braces, bolts, tie rods or the equivalent,
				  except when ladders are built entirely of species listed in §
										21.61 (relating to group one
				  wood). In this latter case the treads may be fastened by two inch screws or
				  equivalent and secured at intervals not greater than 4 feet apart along the
				  length of the rail by braces, bolts, tie rods or the equivalent.
(h)
Cleats.
Wood cleats
				  shall be housed into side rails not less than 1/2 inch or equivalent
				  construction. They shall be fastened to each rail by three 10d wire nails or
				  equivalent.
(i)
Wood
				  steps.
All wood steps 28 inches or more in length shall be reinforced
				  by braces or supported by additional bearings.
(j)
Metal rungs.
Metal rungs
				  shall be securely fastened to the side rails by riveting, bolting or welding.
				  Their position and method of attachment to the rail shall be such as to
				  distribute uniformly the stresses transmitted to the side rail.
(k)
Metal treads.
Metal
				  treads shall be flanged downward not less than two inches at each end of tread
				  and secured to each side rail by two bolts or rivets.
(l)
Old construction.
"U"
				  sections used as steps or rungs, on old construction may be fastened on the
				  outside of the wall by using two 5/8 inch diameter through bolts on each
				  end.
(m)
New construction.
"U" sections used as steps or rungs on new construction shall be
				  built into the structure a minimum of 8 inches with not less than 3 inches of
				  the inner ends bent at right angles. "U" sections shall not be used on smoke
				  stacks.
(n)
Hardware and
				  fittings.
All hardware and fittings shall be securely attached by
				  means of rivets, bolts or the equivalent. The bolts or rivets shall make a
				  close fit in the holes prepared to receive them.
(o)
Movable parts.
The
				  construction and assembly of the movable parts of ladders shall be such that
				  they operate freely without binding or unnecessary play.
(p)
Slipping.
Portable,
				  extension, and sectional ladders shall be either equipped with approved devices
				  or shall be so placed, fastened or held as to prevent slipping.
(q)
Portable ladder hooks.
When service conditions warrant, hooks may be attached at or near the top of
				  portable ladders to give added security.
(r)
Hooks.
Hooks shall be
				  securely bolted or riveted to the side rails or equivalent construction, and
				  shall be of such dimensions as to withstand the loads imposed upon
				  them.
(s)
Special ladders.
Ladders of special design shall be of an approved type.
This section cited in 34 Pa. Code §
												21.40 (relating to step
						ladders).