How Are Hurricane Impact Windows Rated?

Once the wind of a hurricane or severe storm gets inside a house, the home’s structure and even the roof most likely will not survive. The pressure that builds up tends to cause separation of elements within the building and can be devastating in just a matter of minutes. For this reason, impact windows are needed and should be installed in the home. Impact windows need to undergo rigorous testing in order to make them efficient.

Impact windows go through a design pressure test that will ensure the windows will be able to hold up during dangerous major storms. The test consists of three parts:

1. Air Pressure

2. Water Penetration

3. Structural Testing

Air Pressure

Usually, the first test is air filtration. It is simulated to measure the pressure on the windows. Air filtration pressure alone does not affect the pressure rating of the window.

Water Penetration

The amount of water that the windows keep out is tested by pressure and is based on the type of window being tested. It is tested by the percentage of water pressure that is kept out.

Structural Testing

The glass and frame of the window are tested. A higher rating is given due to the thickness of the glass and the hardware of the frame. When higher-end and structurally sound material is used the rating is usually higher. The rating of the frame can actually increase the overall rating of the window itself.

Further Rating Requirements

Since Florida, especially to the south, is a hotbed for severe storms and hurricanes, it has additional requirements for testing impact windows. The tests cover the typical air, water, and structural testing for rating impact resistant windows. But an additional test involves impact resistance. This test is done by firing a 2x4 piece of wood twice to see if the window successfully holds.   

Before having impact windows installed in your home, make sure that you know how they are tested and the rating they have received.