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Feature - Roofing
and Cladding
Handle with Care
As glass finds increasing usage in construction, it is important
to use it safely.
lass is becoming an important component of buildings, playing
multi-functional roles. From cladd-ing to doors, panels, staircases
and flooring, this versatile material is finding numerous
applications. Fragile glass can become as tough as steel with
appropriate treatment. Though the usage of glass is growing,
it is important to know how to use it effectively and efficiently
to prevent damage and injury.
To aid this process, the Confederation of Construction Products
and Services, a non-profit organisation dedicated to sustainable
growth of construction products, has compiled a few guidelines
on use of glass in construction.
Accident zone
If you look at the accident statistics involving glass, it
is noticed that the glazing in some locations in buildings
are more vulnerable to human impact than in others. These
critical locations include the following:
a) In-and-around doors, low windows;
b) Panels mistaken for a doorway or opening;
c) Panels at low levels in walls and partitions;
d) Bathrooms;
e) Buildings associated with special activities e.g. gymnasium,
enclosed swimming pool etc;
f) Schools and childcare facilities;
g) Nursing homes and facilities for the elderly.
Precautions
Glass in a door, side panel or a panel capable of being mistaken
for a doorway or opening, which is not made apparent by transoms,
colonial bars, other components of a glazing system or any
other decorative treatment, should be marked to make it visible.
A band or marking is not required when:
a) Height of the glass is not greater than 1,000 mm at any
point.
b) The width of the glass is not greater than 500 mm at any
part (this applies to overall panel assembly not individual
glass pieces in case of faceted glazing)
c) When there is no glass within 700 mm of the floor.
d) The glass is provided with at least one fixed glazing bar,
firmly attached to the styles to locate and protect each face
of the glass.
Alternatively, patterns may be used as an acceptable form
of marking.
Breaking point
Since glass is vulnerable to breakage, it is important to
ensure that falling pieces
do not cause injuries. These are a few points to consider
while working with glass:
(a) Broken annealed glass falling on people can cause grievous
or even fatal injuries. Hence safety glass is recommended
in locations where the risk of people getting hurt by falling
glass is high.
(b) Toughened (tempered) glass has a safe breakage pattern
as it breaks and disintegrates into small and relatively harmless
particles. However thick toughened glass particles may stay
interlocked and fall as lumps, and these multiple particles
can cause a minor or medium injury mainly due to the weight
of the cluster.
(c) Laminated safety glass will generally not fall out of
the fixing. However,
laminated glass, with both glasses toughened, may crumple
as a blanket and fall out of the fixing in case of a failure.
This factor needs to be considered while designing horizontal
and sloped glazing.
(d) If broken, safety organic coated glass will be difficult
to penetrate provided the covering is applied in accordance
with the manufacturer’s recommendations.
(e) Any broken glass in a glazing should be removed immediately
on breakage.
(f) The glazing system should have the strength to hold glass
in place and prevent it from falling out as a whole.
Box
Know Your Glass
Toughened (tempered) safety glass
A single piece of specially heat-treated or chemically treated
glass, with a stress pattern such that the piece when fractured
reduces to numerous granular fragments, with no large jagged
edges.
Laminated safety glass
Two or more pieces of glass held together by an interleaving
layer or
layers of plastic materials. The laminated glass will crack
and break under sufficient impact, but the pieces of glass
tend to adhere to the plastic and do not fly. If a hole is
made, the edges are likely to be less jagged than
ordinary glass.
Safety organic-coated glass
A glazing material consisting of a piece of glass coated and
permanently bonded on one or both sides with a continuous
polymeric
coating, sheet or film, which meets the test requirements
of the safety glazing standards.
All heat-treated glasses are not safety glasses and all laminated,
toughened and safety organic coated glasses also are not safety
glasses. Heat strengthened glasses and annealed glasses also
are not classified as safety glasses unless laminated to meet
the test specified for safety glass. Glass laminated with
other than polyvinyl butyral (PVB) may not meet the requirement
of safety glass.
All window glass films are not safety films unless these are
of the required minimum thickness and type, and pass the test
standards.
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