Why Do Car Windows Shatter When They Break?

Car windows, particularly the door windows, other side windows, and rear windshield, are prone to damage from many different sources. Cracks and other kinds of damage include:

  • Rocks kicked up from passing traffic
  • Stress from improper alignment
  • Stress from an object stuck in the track
  • An accident
  • Vandalism

While the front windshield is made from two layers of safety glass laminated together with a plastic layer between, the side and rear windows are made from a single layer of safety glass. Safety glass is designed in a way that, with a significant impact, it completely shatters into pebble-sized pieces. These tiny bits of glass are much less sharp than typical broken plate glass, and there are no sharp and pointy shards that form when safety glass shatters.

Safety glass is formed through a process known as tempering. The glass is heated, then cooled rapidly. The outside part of the glass is put into a state of compression, while the inside part of the glass is under tension. This process is what causes a glass impact to cause a shattered window when you hit the window.

Because the window shatters instead of cracking, a shattered window will need to be replaced immediately. Some pieces of the shattered window may remain connected and in place, and should be cleared using safety equipment before trying to drive. Also, clean any safety glass up, including vacuuming the seating surfaces and carpet, to prevent the possibility of injury or cuts if you come into contact with the shattered glass.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

Windshield Laws in Washington
Any Any time you drive a vehicle on the roads in Washington, you know you have to follow the traffic rules to make sure you and those around you make it to the desired destination. Motorists are also required to...
How to Tint a Car Window
Window Window tint (https://www.yourmechanic.com/article/all-about-window-tinting-and-why-you-should-care) is a popular car customization today. It is used for several reasons, including: Increased visibility by reducing glare and the bright sun Privacy while you are inside your vehicle Protection from the sun’s UV rays Security...
How to Reset Automatic Windows
Technology Technology is great most of the time. It used to be that you could replace the battery in your vehicle and not have to worry. However, many modern cars will lose the automatic window function after battery replacement (https://www.yourmechanic.com/article/how-to-change-a-car-battery_2)....

Related questions

How do I use the window lockout?
The window lockout is an important safety feature. When the window lockout is in use, the rear windows cannot be rolled down with the rear window switches (they can still be rolled down with the driver door switches). To turn...
Back power window not working
Hello. If you have one window that stopped working it is typically caused by a window motor or regulator. These typically need to be replaced together. I typically remove the door panel and check to see if there is power...
After replacing the window regulator in my 2002 Ford Windstar the window goes up crooked.
Hi there. The window regulator is loose or the window is off the window regulator causing the window to go up crooked. Remove the door panel and check the window regulator and see if it's not mounted properly. If the...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com