After hurricane Andrew in the year of 1992, all the
homes and commercial businesses in Florida were required to abide by the Miami
Dade building code and have impact windows in their structures. Impact windows
have more strength than the traditional windows as they are made of
multi-layered glass materials and can withstand flying objects that often break
the windows during hurricanes and storms. Now, impact windows and doors in Florida are also necessary for
obtaining insurance coverage.
Testing
procedure for impact windows
Impact windows are designed so that they can provide
protection against flying objects. During hurricanes many objects like tree stems,
glasses, iron rods, etc. may fly in the air because of high pressure and
tremendously fast winds and strike the window panels and damage them. These
objects may also enter inside homes and cause damage to life and property.
According to the Miami Dade guidelines, the high impact windows must pass the
impact test. The large missile test uses a 9 lb object of dimensions 2 inches
by 4 inches by 6 inches that is thrown with a speed of 34 mph. The impact
window must also be able to pass wind cycles of 9000 and the maximum hole size
that they should sustain should be 1/16
by 5 inch (in the glass’s inner layer).
The windows that are located at or below 30 feet
should be able to pass the large missile test. Windows that are above 30 feet
height should be able to pass both small and large missile test.
Composition
of impact windows
You can think of impact windows as being heavy duty windshields
that are more resistant to breakage in comparison to ordinary window glasses.
These high quality and high strength impact windows consist of 3 layers of
usually 2 kinds of glasses. These glass types are Sentry Glass Plus (SGP) and Polyvinyl
(PVB). Out of these, SGP is the more strength wielding glass and is used for a large
missile test.
Further, window panes manufacturers also add a new space
and one extra glass panel to achieve the Energy Star Rating. These additions to
your impact glass windows provide a dead-air area/space in between the windows
so that they do not lose energy and provide for energy saving. Some
manufacturers also employ the 16 chamber strength vinyl extrusion in impact windows in Florida that provides
utmost hurricane-wind protection.
