One of the most frequently asked questions we receive from customers is if window film will cause their glass to break. This is actually nothing more than a common myth. Many have been led to believe that window film can cause thermal stress on the glass and cause the window to break. This myth is based on window films causing a slight increase to the thermal stress on the glass due to the sunlight.

While thermal stress can be a concern, the misconception does not take into account a few other key factors. The relative strength of the glass and heat tolerance levels of different types of glass are all factors that need to be taken into account. On top of that, 3M Window Films along with our professional team of installers use specific manufacturing techniques and processes that avoids the risk of thermal stress breakage.

Residential and commercial window breakage from thermal stress is actually quite rare. Our 3M Window Films come with strict film-to-glass thermal stress compatibility guidelines that we follow to ensure your windows are protected and you receive top-quality products backed with the 3M Guarantee. Continue reading below to learn more about the dynamics of thermal breakage and how we account for this.

Thermal stress can occur when glass is exposed to excessive temperature variations. When the temperature variations are greater, the chances for thermal stress are greater as well. Different parts of windows receive different amounts of heat and sunlight – for example, the center of a window can get direct sunlight while the edges get less. The energy from the sun heats the center of the window causing it to expand. This expansion can put pressure on the edges which are cooler, when this pressure exceeds the overall strength of the glass it can lead to fractures.

There are many different types of glass and each have their own levels of strength. For example, tempered glass is extremely strong and will only suffer thermal breakage from fire which is why it’s often used in many architectural applications (including storefront windows and doors). Another type of glass is heat-strengthened glass and it can withstand a heath threshold of almost 500 degrees Fahrenheit!

Temperature difference thresholds for other glass types include:

In general, thermal breakage is not a concern with tempered and heat strengthened window glass. However, it does need to be considered in relation to other window glass types.

The window film experts at Suncoast Window Films fully understand the in’s and out’s of thermal stress. We conduct detailed compatibility evaluations prior to install to ensure proper compatibility. Our installers will consider numerous factors such as glass type, color, size, thickness, frame type, solar energy intensity, absorption, and more to ensure proper compatibility. To provide extra peace of mind we also provide the 3M Guarantee which gives you one of the best warranties on the market.

Suncoast Window Films is an Authorized 3M Prestige Dealer with over one hundred five-star reviews from happy customers in our area. If you are interested in window films for your home, please contact our window film specialists today at (941) 417-4000 or get your free consultation by clicking here.