WAC 296-155-24515
Guarding of low pitched roof
perimeters. (1) General provisions. During the performance
of work on low pitched roofs with a potential fall hazard
greater than ten feet, the employer shall ensure that
employees engaged in such work be protected from falling from
all unprotected sides and edges of the roof as follows:
(a) By the use of a fall restraint or fall arrest
systems, as defined in WAC 296-155-24510; or
(b) By the use of a warning line system erected and
maintained as provided in subsection (3) of this section and
supplemented for employees working between the warning line
and the roof edge by the use of a safety monitor system as
described in WAC 296-155-24521.
(c) Mechanical equipment shall be used or stored only in
areas where employees are protected by a warning line system,
or fall restraint, or fall arrest systems as described in WAC 296-155-24510. Mechanical equipment may not be used or stored
where the only protection is provided by the use of a safety
monitor.
(2) Exceptions.
(a) The provisions of subsection (1)(a) of this section
do not apply at points of access such as stairways, ladders,
and ramps, or when employees are on the roof only to inspect,
investigate, or estimate roof level conditions. Roof edge
materials handling areas and materials storage areas shall be
guarded as provided in subsection (4) of this section.
(b) Employees engaged in roofing on low-pitched roofs
less than fifty feet wide, may elect to use a safety monitor
system without warning lines.
Note:
See Appendix A to Part C-1 -- Determining roof widths nonmandatory guidelines for complying with WAC 296-155-24515 (2)(b).
(3) Warning lines systems.
(a) Warning lines shall be erected around all sides of
the work area.
(i) When mechanical equipment is not being used, the
warning line shall be erected not less than six feet (1.8
meters) from the edge of the roof.
(ii) When mechanical equipment is being used, the warning
line shall be erected not less than six feet (1.8 meters) from
the roof edge which is parallel to the direction of mechanical
equipment operation, and not less than ten feet (3.1 meters)
from the roof edge which is perpendicular to the direction of
mechanical equipment operation.
(b) The warning line shall consist of a rope, wire, or
chain and supporting stanchions erected as follows:
(i) The rope, wire, or chain shall be flagged at not more
than six foot (1.8 meter) intervals with high visibility
material.
(ii) The rope, wire, or chain shall be rigged and
supported in such a way that its lowest point (including sag)
is no less than 36 inches (91.4 cm) from the roof surface and
its highest point is no more than 42 inches (106.7 cm) from
the roof surface.
(iii) After being erected, with the rope, wire or chain
attached, stanchions shall be capable of resisting, without
tipping over, a force of at least 16 pounds (71 Newtons)
applied horizontally against the stanchion, thirty inches
(0.76 meters) above the roof surface, perpendicular to the
warning line, and in the direction of the roof edge.
(iv) The rope, wire, or chain shall have a minimum
tensile strength of 200 pounds (90 kilograms), and after being
attached to the stanchions, shall be capable of supporting,
without breaking, the loads applied to the stanchions.
(v) The line shall be attached at each stanchion in such
a way that pulling on one section of the line between
stanchions will not result in slack being taken up in adjacent
sections before the stanchion tips over.
(c) Access paths shall be erected as follows:
(i) Points of access, materials handling areas, and
storage areas shall be connected to the work area by a clear
access path formed by two warning lines.
(ii) When the path to a point of access is not in use, a
rope, wire, or chain, equal in strength and height to the
warning line, shall be placed across the path at the point
where the path intersects the warning line erected around the
work area.
(4) Roof edge materials handling areas and materials
storage. Employees working in a roof edge materials handling
or materials storage area located on a low pitched roof with a
ground to eave height greater than ten feet shall be protected
from falling along all unprotected roof sides and edges of the
area.
(a) When guardrails are used at hoisting areas, a minimum
of four feet of guardrail shall be erected on each side of the
access point through which materials are hoisted.
(b) A chain or gate shall be placed across the opening
between the guardrail sections when hoisting operations are
not taking place.
(c) When guardrails are used at bitumen pipe outlet, a
minimum of four feet of guardrail shall be erected on each
side of the pipe.
(d) When safety belt/harness systems are used, they shall
not be attached to the hoist.
(e) When fall restraint systems are used, they shall be
rigged to allow the movement of employees only as far as the
roof edge.
(f) Materials shall not be stored within six feet of the
roof edge unless guardrails are erected at the roof edge.