| We provide excellent window cleaning
consulting. In California, roof tie-back anchors are required on all buildings
exceeding 36 feet in height for “unscheduled” maintenance.
Most high-rise roof tops around the country have them for safety line
tie-offs. In either case, the anchors are structurally designed to safely
carry a line load of 5,400 pounds in any direction. The load requirement
recently reduced to a 5,000 pound capacity, incorporates the requirement
for dynamic loading of a 250 pound man free falling six feet before being
quickly de-accelerated in a stopping condition, multiplied by a four to
one safety factor. The design clause, “in any direction” is
required due to the unpredictable nature of a cleaner’s set up.
An anchor that is adjacent to one drop may actually be used as a safety
line tie-off for another drop on the other side of the building.
Buildings without direct roof attachment capability,
used with davits or outriggers, often rely on structural parapets to support
the load of the platform or manned chair. As a steel fixture, fitting
over the parapet cap, a parapet clamp or parapet hook is carried form
building to building. |
