Two workers installed a portable powered
platform (swing stage) for painting the exterior of a commercial
building. The swing stage was suspended from two parapet
clamps attached to a parapet wall, which was constructed
of brick and mortar but covered by new metal flashing. The
parapet wall was not inspected for structural integrity
before the clamps were attached.
The workers boarded the swing stage at level one, with
one worker at each end. As the swing stage was descending,
the parapet wall suddenly collapsed and one end of the platform
fell about 3 metres (10 feet). One worker was injured when
he was struck by falling debris from the collapsed wall.
He suffered serious injuries.
Safe work practices:
- Inspect parapet walls to confirm their structural
integrity before using parapet clamps to support suspended
equipment.
- If the surface cover of the parapet wall prevents
inspection of its structural components, or if the parapet
is of unknown construction, or if the strength of a
parapet wall is not known, have a professional engineer
determine its strength before the wall is used to support
suspended equipment.
- If the structural integrity of a parapet wall cannot
be confirmed, use an alternative suspension method that
does not bear on the parapet wall, such as thrust-out
beams and counterweights.
