When a severe weather event hits your area, nothing is more important than your safety and the safety your loved ones. And equipping your home with the tools it needs to help withstand a storm will not only help protect you. It can protect your most prized investment—your home—as well as the property inside it.
Over the last quarter century, windows have proven to be critical in helping your home stand up to extreme weather such as a hurricane, or in some cases, a tornado.
Impact-resistant windows have come on strong over the past two decades, largely following trends coming from the hurricane-savvy South Florida region.
The massive destruction left in the wake of Hurricane Andrew in 1992 placed immediate attention on the need for structural improvement of homes in hurricane-prone areas. Windows were a key focus.
A broken window or door failure during a high air-pressure event can compromise the integrity of a home and send dangerous debris—including broken glass—through the building at high speeds. This kind of force can be so extreme that it actually blows the roof off the house.
After Hurricane Andrew, local building codes officials in South Florida soon demanded more stringent window strength requirements. Many state, national and international building codes followed suit. The building code in South Florida requires all homes constructed after July 2001 use hurricane shutters or impact-resistant glazing for their exterior openings.
Over time, window companies have continued to improve their products to accommodate this. Many now even exceed requirements and standards related to impact-resistant windows. So while options such as installing temporary plywood or permanent hurricane shudders are common, impact window technology—which continues to improve every year—provides homeowners with a real solution.
Note: The terms “hurricane windows” and “impact-resistant windows” are often used interchangeably, and sometimes for windows that don’t actually meet impact standards. So for this purpose, we are using the terms “impact windows” and “impact-resistant windows” without the word “hurricane.”
The windshield industry has long taken advantage of laminated glass technology. This is a glass fabrication method in which two piece of glass are sandwiched together with a plastic interlayer in between. The interlayer helps keep the glass in place and holds it together when it is impacted.
This technology came to the forefront of the development of higher impact-resistant windows. However, the glass isn’t the only factor. Impact windows require a much sturdier frame than your average window in order to keep the glass inside it, and to prevent the frame itself from coming apart. The frames typically are made of metal, wood or vinyl and may use additional materials to further strengthen the window.
Varying levels of protection and strength are available on the door and window market depending the application and requirements. Some home windows will use thicker glass, a thicker interlayer, or both. Others may even include other reinforcement materials such as polycarbonate.
How do window manufacturers prove that their products are in fact impact-resistant? Well, they undergo rigorous third-party testing to ensure the windows are up to the task.
The most common type of test is a missile test, in which a nine-pound two-by-four piece of wood is launched at 34 miles per hour at the center of the window. Some codes require even higher testing standards, with a faster missile test speed and/or the addition of a wind pressure cycle, which simulates high wind speeds after the window is hit.
These stringent guidelines are based on standards from ASTM, which develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems and services.
Because of their make-up, impact-resistant doors and windows actually provide a range of additional benefits aside from guarding your home against extreme weather.
Since impact-resistant windows usually are made of laminated glass, this provides added security to your home, because laminated glass is more difficult to break through and is often used for security applications. It also provides a safety element, since the glass will not shatter into multiple pieces but instead is designed to hold together if someone were to run into it.
Additionally, the plastic interlayer that is used as lamination has sound-dampening properties. This gives a level of protection against outside noise. The interlayer also can lessen the degree of ultraviolet light from the sun that can provide damage or fading to materials in your home.
The beautiful thing about impact windows are that because they’re so prevalent in modern day home building and design, they come in all shapes, sizes and forms.
The leading manufacturers in the industry produce everything from casement windows that swing open and fixed windows that stay shut to hung windows that slide up or down and rolling windows that slide side-to-side.
In recent years, the glass and window industries have given more attention to how their product could hold up in a tornado situation. Testing is being developed for this reason, but it is much more stringent than the standard impact-resistant requirements we referenced earlier.
In a future blog post, we will explore this and other development in “storm windows.”Read More