Your windshield and other windows are extremely important parts of your vehicle’s structural integrity. They provide rigidity in the body and prevent vehicle sway, much like the sway bar does underneath. But once your windows are compromised, they can crack or shatter. The following situations can lead to cracked or shattered windows:
- Stone chip in one of the windows
- Crack in the glass
- Stress from an improper installation
- Pressure from misalignment
No matter what it is, if there is a flaw in your window it can crack or shatter when the temperature drops.
How extreme cold affects the glass
Extreme cold temperatures cause everything to contract. Metal, rubber, sealant, and even glass are subject to expansion and contraction in any temperature difference. When your glass is exposed to extreme cold, there won’t be a problem if your glass is in good condition and installed correctly. Even though the glass will contract at a different rate than the metal, the sealant that holds the window has enough flexibility to allow the windshield to maintain its integrity. There is more stress on the glass, but its structure is able to withstand the pressure.
If your glass is chipped or cracked, the extra pressure on the glass can cause your window or windshield to crack or shatter, though it is more common for cracks to form than for the window to shatter. The crack will typically form from the point of weakness and extend towards the edge, but not always.
If the windshield is improperly installed, such as being replaced when the car is not on level ground, there can be stress on the window already, even without factoring in the extreme cold. Once the window is exposed to cold temperatures, the extra stress can crack the window. This type of crack usually forms from the outer edge and stretches into the center of the glass.
Because your window can break in extreme cold weather, it is very important to have any damaged windows replaced as soon as possible.
This article originally appeared on YourMechanic.com as Can Extreme Cold Temperatures Break Car Windows and Windshields? and was authored by Jason Unrau.