Impact Windows and Their Use for Home Protection during Hurricanes

 

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.