Thursday, March 10, 2011

Achieving Window Security from the Glass

It may sound odd to increase the security of a window or door from the use of glass, but there are types of glass that are harder to penetrate than standard glass used in windows and doors.
By a vast majority, the two most common types of glass used in windows and doors is:

1. Annealed glass, and 2. Tempered glass.
Annealed glass is the typical glass used in windows, unless tempered is required. When broken it has the tendency to leave behind shards that can cause injuries by cutting when coming into contact with anyone or anything. It is also the least expensive.
Tempered glass is designed to shatter, when hit, into small, jelly bean sized chunks to prevent injuries from sharp glass. All doors, swinging or sliding must, by code, have tempered glass.

A third type of glass, laminated, is useful when security is a priority. Laminated glass is essentially a “sandwich” of two pieces of glass on either side of a flexible but tough, clear core that bonds the two pieces together. Security is achieved because, even though the glass can break, the inner core holds both pieces together and doesn’t easily permit penetration. So even if the bad guys break the glass of a laminated glass window, they can’t readily get inside the home. Repeated thrusts must be made into a window or door with laminated glass to eventually create an opening large enough to permit entry. (By then, the prowler has probably moved onto easier pickins’.) The ability of the laminated glass to hold itself together is obvious to those of us who have driven by a bad car accident and seen a crumpled windshield on the side of the road. Made of laminated glass, the windshield stays together even though severely damaged.

In hurricane prone areas, laminated glass can provide a measure of protection from wind whipped debris smashing through a window or door and causing injury.

Another benefit of laminated glass is its’ inherent sound resistance characteristics. But that is a topic for another time.