Potential Risks: Can Window Film Damage Your Windows?

Installing films on your windows is one of the easiest and cost-effective ways to make your interior spaces more comfortable and boost the energy efficiency of the entire structure at the same time. The thing is, there’s plenty of misinformation floating around, so it’s only natural to wonder can window film damage windows.

Spoiler alert:

While risks do exist, most potential issues are the result of either poor installation or improper choice of window film.

In short, most (if not all) window film risks are completely preventable if you select the correct types and install them properly. And yes, going about this the right way will also preserve any window warranty protections.

Can Window Film Damage Windows? Debunking the Myth

Applying window film doesn’t break glass on its own. However, it can contribute to thermal stress or exacerbate pre-existing weaknesses in the glass.

Thermal stress is a key concern. Different areas of a glass pane absorb sunlight differently. The center often gets the most direct sun exposure and heats up more than the shaded edges, which are insulated by the window frame. Since glass expands when heated, the hotter center pushes against the cooler edges. If the stress exceeds the glass's strength, it can result in thermal stress window damage.

Though this sounds alarming, most modern glass types can withstand this stress just fine, even with window film. The type of glass plays a critical role here, as each has its own tolerance for heat and pressure. For instance, tempered glass is a perfect match for most types of window films due to its heat resistance.

That said, window film glass compatibility matters. Tempered glass, when employed in insulated units (double glazing), bumps up the complexity as heat can become trapped between the panes, contributing to seal failure or causing cracks. In such cases, solar control film specifically tested for insulated or low-e glass is the best way to go, as it helps manage solar heat gain and reduces stress on the glass.

Apart from thermal stress, window damage can occur if you install film on defective glass that is already cracked.

Other, less costly types of damage may include:

-Peeling
-Bubbles
-Fading

These issues are usually the result of improper DIY installation (applying film unevenly or over dirty glass) or using low-quality, poorly manufactured film.

How Certified Window Films Reduce the Risk of Damage

The adage of ’you get what you pay for’ rings true even when talking about window films. It may seem like an insignificant factor, but the quality of the adhesive absolutely matters in avoiding the risks we discussed previously.

In addition to cheaper window films looking too dark or having a metallic-like tint, they’re more prone to bubbling and peeling when exposed to sunlight. Even worse, bargain films may also be inefficient in blocking the sun’s rays, which may directly contribute to thermal stress and window damage.

In contrast, certified adhesive solutions quantify the percentage of solar energy rejection and retention, with rigorous engineering and testing extending to the overall solar ratio. This refers to how solar energy is divided. Put differently, it accounts for the percentage of the solar energy that the film rejects, absorbs, and transmits.

As a result, these safe window films help the thermal load management by reducing internal glass temperature, distributing the heat across the surface more evenly, and preventing sharp thermal changes that often lead to thermal stress damage.

Reputable brands also provide clear film-to-glass compatibility charts. These materials may include information such as:

-Which types of glass is the film approved for
-Restrictions such as pane sizes, edge clearance, etc.
-Maintenance instructions

These resources can help you (or preferably, your installation professional) assess the risks and select the right type of film that won’t be susceptible to thermal stressor damage.

Why Professional Installation Matters for Warranty Compliance

Window warranty and film are generally discussed together, as most people worry if installing window film will void the warranty.

Although the answer depends solely on the window manufacturer (applying window film requires removing the seal, which may automatically void the warranty with some brands), to ensure the best possible outcome, you should always opt for professional installation.

For starters, using products certified according to relevant standards issued by the European Committee for Standardization such as EN 1096 (European standards that refer to coated glass and test methods for different coating classes), as well as EN 12600 (evaluates impact resistance of window films) and M1 fire resistance ratings is a must, as you’ll reduce the risk of damage and increase the possibility of preserving your window warranty.

Moreover, reputable window film brands often offer their own warranty, which is contingent on having the window installed by a certified expert.

So, if preserving the warranty and, by extension, keeping your glazing in one piece is your end goal, steer clear of DIY installation.

Keep Your Windows Safe

As you can see, taking a few precautions and sourcing aid from a professional can pretty much eliminate the possibility of window films damaging your windows.

Granted, this can be overwhelming, especially considering just how many moving parts are involved in finding a perfect window film. If you need a bit more clarity, you can always reach out to an expert to get all the information on window film glass compatibility you’ll ever need and find the ideal adhesive for your project. Remember, your peace of mind is worth it.