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The most stringent requirements in the new Texas code concern protection of all openings, such as windows, doors and garage doors and their ability to withstand the impact of flying debris. This applies to homes seaward of the Intracoastal Canal. According to construction experts, window protection represents the first line of defense in protecting a building from the destructive winds of a hurricane. When glass windows are broken, hurricane force winds can rush into the home and trigger roof failure or other severe structural damage, as well as wind and rain damage to its contents. The window protection measure is designed to protect against window breakage and thus help prevent internal pressurization, as well as to prevent damage to building contents and the building interior.
More than 300 products (windows, shutters and doors) have met these impact standards and have proven to be economically attractive. Among these products is laminated glass, which looks like ordinary glass but is much tougher. Traditionally used in automobile windshields, laminated glass is composed of a tough polyvinyl butyral (PVB) plastic interlayer material permanently bonded between two panes of glass. Windows and doors made with hurricane resistant laminated glass can help maintain the protective "envelope" of a home. Upon impact the glass may break, but the broken glass pieces tend to adhere to the plastic interlayer and remain in the opening, thus preserving the building envelope. Window systems using laminated glass products have passed the impact test adopted in Dade, Broward and areas of Palm Beach Counties in south Florida. This testing includes a large-missile impact test which consists of a 9-pound 2 by 4 timber fired from an air cannon at 34 mph to simulate the force of a piece of flying debris in a hurricane. Following the large-missile impact test, the impacted window, shutter, or door undergoes a series of wind-load tests to stimulate the pressures created by hurricane winds. These tests have become the standard for testing not only in Florida, but among product manufacturers nationwide.
Contrary to a popular view, window systems with code approved laminated glass are less expensive than windows plus roll-up or accordion shutter systems, when used in new construction. In a recent study commissioned by the North American Laminated Glass Information Center, laminated glass proved to be less than one-half the cost of windows with manual roll-up shutters. The study by Associated Cost Engineers in Orlando, Florida, compared the cost of installing laminated glass windows with the cost of installing conventional windows plus manual roll-up or accordion shutters. The study also found that laminated glass costs 20% less than windows with accordion shutter systems. The real advantages in using laminated glass windows are that it does not have to be operated or activated in advance of the storm and it has a better appearance on the home.
"After the new code becomes effective in Texas, housing construction will most likely follow that in south Florida. Builders have learned that often people are willing to pay a little extra for the added security of their homes and their families during a hurricane," says Minor. Similar to south Florida code standards, the new law will allow for insurance rate reductions issued by the Texas CATPOOL for homes built to the new code standards. Two years after the building codes went into effect, south Florida is experiencing a building boom that is likely to continue until the year 2001.
For more information about laminated glass, including its other architectural properties, contact the North American Laminated Glass Information Center (LGIC) at 1-800-230-4527. The LGIC also maintains a site on the Internet World Wide Web at the address http://lgic.glass-info.com. The LGIC's E-mail address is lgic@glass-info.com.
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