Does Installing Window Film Cause the Window Seal to Fail?

Stephanie Shaykin
Updated September 28, 2021
Parents and son on sofa in living room with large windows
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Can a window film seal your window's fate?

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Window film is an excellent choice if you need to block out UV rays from entering through your windows or if you’re looking for a little more privacy. But despite its benefits, some homeowners might be wary about the film disturbing a window's seal—but there’s really nothing to worry about.

What Are Window Seals?

Windows with multiple panes typically have a seal between each one. The seals create a protective barrier that keeps outside temperatures from entering your home, keeping your house cooler in the summer and warmer in the snowy winter.

Will Using Window Film Damage the Seal?

Applying window film on window
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There are a few reasons why window seals fail, but none of them are because of window film. Some reasons are:

  • Sun rays expanding and putting pressure on the seal

  • Extreme weather, including hail

  • Improper maintenance

Signs That a Window Seal Is Broken

A window seal always has the potential to fail. Here’s how you can tell when your window seal breaks.

Your Window Looks Dirty, Even After Cleaning

You might think you’re going crazy when you just washed your window and it’s still dirty. Well, you’re not crazy. A seal failure lets bugs, dirt, and debris sneak behind your window panes.


When the window seal breaks, the panes become exposed to extra moisture. So if your windows are foggy with mist, even on a clear day, you might have a seal problem.

Distorted Window Panes

When the seal fails, air flows in, distorting the way your panes look.

Causes of Window Seal Failure

More often than not, seal failure happens when there is window damage during shipping or installation—not because of your window film. Also, if you live somewhere with high levels of humidity and extreme fluctuating temperatures, your window seals can break due to wear and tear.

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