Why Did My Windshield Crack


January 15, 2018

At this time of year, we often get calls from customers saying they were surprised by a windshield crack that seemingly happened for no reason.

At this time of year, we often get calls from customers saying they were surprised by a windshield crack that seemingly happened for no reason. It is obvious if a rock hits your car while driving down the road, or if you are hit by a hailstorm. But here, we’ll discuss other, more hidden underlying reasons for some windshield cracks.


Extreme changes in temperature can have a damaging effect on auto glass. When the sun heats up metal around the edges of the windshield, that portion of the glass warms up faster than the rest, and this can cause cracks. The same can be true for other causes of temperature fluctuations – like using the heater or defroster on a particularly chilly day. Expansions and contractions can happen at varying rates, causing the damage to occur that only later reveals itself.

Ice Scrapers & Windshield Wipers 

Scraping too aggressively at the ice accumulated on your windshield can aggravate existing, small, unseen chip or cracks, so scrape with care. And running the wipers over a dirty windshield can force particles into existing cracks, thereby worsening them.

Imperfections in the Glass

Not all glass is created equally. Just as in other consumer products, there are varying grades of quality. You may have glass that was simply manufactured with invisible flaws, or that has even been recalled by the auto maker.

Commuter Wear & Tear

Driving at highway speeds year after year can take its toll. It leaves the windshield vulnerable to sudden shocks from speed bumps, pot holes, or road debris, that over time can result in pitting or a crack that appears seemingly out of the blue.

Flawed Installation

Let’s face it, nobody’s perfect. Even from the factory, mistakes can and do happen. When windshield installations are too loose, vibrations can cause stress cracks.

Wind and Pressure

We’ve all noticed the weather getting weirder lately. A high gust of wind is sometimes all it takes to jostle a windshield just enough to cause damage. Additionally, the pressure of setting something heavy against your automotive glass can be enough to cause trouble later on down the road.

If any of this has every happened to you, and a tiny, barely noticeable crack appears, ignore it at your own peril. Even if the trouble spot is out of your direct line of sight while driving, it is important to address the issue before it becomes worse, or even becomes a safety hazard. The danger is not only in obscuring visibility. Your car or truck’s windshield serves as structural support. If involved in a crash, the windshield could pop out of place and even result in the roof collapsing on your vehicle.

In many cases, little star, oyster shell, or bullseye shaped breaks can be repaired with out total windshield replacement. By not procrastinating, addressing these small problems early can save you both time and money by not allowing the issue to worsen.

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