Install Impact-Resistant Windows

05/03/2023

Why do they matter?

When wind forces enter your home, the pressure can build up until it eventually causes the weakest part of your home to rupture. Think of it like blowing up a balloon. Once the internal pressure reaches a certain level, it pops. That is why it is essential to protect all your home’s openings (windows, entry doors, garage doors, skylights, sliding doors, gable end vents, etc.) to keep the wind and pressure out.

When you protect your openings, they can resist impacts from hail or windborne debris like flying missiles, tree limbs, or roofing material that break windows and breach doors and allow pressurization to occur. Protecting your openings and keeping them intact can prevent wind-driven rain and moisture from entering your home as well.

One of the most effective opening protection options is to install impact-resistant windows.

What do I need to know?

• Impact-resistant windows are made with special glass that will not fall out of the frame and let wind and water into the house.
• Impact glass is similar to the laminated windshield in your car. It may crack and break, but it will not come apart easily.
• Impact-resistant windows are always in place to protect the home, so you do not have to install or activate their protection.
• Typically, impact-resistant windows are more expensive than standard windows, but the extra cost may not be prohibitive compared to mid-to upper-range windows. Further, the cost of impact-resistant windows may equal the cost combination of new standard windows plus a shuttering system.
• Impact-resistant windows are tested and rated with large and small missile tests.
• Large missile: A six feet, nine lb. 2 x 4 missile fired at 50 feet per second.
• Small missile: Thirty pieces of roof gravel fired at 80 feet per second.
• Compliant impact-resistant windows, shutters, and doors carry proof of compliance identified on a sticker or label or imprinted into the product. Additionally, the product paperwork should document compliance with all relevant testing standards.
• Follow manufacturer specifications when installing impact-resistant windows. Improper installation may cause a voided warranty or, worse, a product failure that presents a threat to life and property. Learn more about installing windows here.
• If impact-resistant windows are not an option for you, you can install shutters that can absorb the shock of windborne debris without allowing the window glass to break. Learn more about hurricane shutters options here.

Where do I start?

Replacing your windows

• Check with your local building department for information about the window design pressure ratings and windborne debris protection requirements that windows should meet.
• Impact-glass cannot be installed in older, existing window frames. It must be installed as a complete window system, including the frame as that is how it is tested.

More Resources:

• FLASH. Resilient Design Guide: High Wind Wood Frame Construction Edition.
• FLASH. Resilient Design Guide: Concrete Construction Edition.