Many factors can cause windshield cracks. To help you prevent this problem, I have compiled a list of common causes that lead to windshield cracks. Most of them are avoidable, whilst others are things you're likely to come with on a daily basis.

1. Gravel roads
While the odds of debris striking the windshield and harming it are minimal, it can nevertheless happen. Maintain a safe distance between your car and other vehicles when driving, as their tread could spit pebbles into your windshield, causing damage.

2. Low-grade glass
If your car’s windshields are made from inferior material, it can easily be scratched or broken. You can either wait for a crack to appear or replace it right away. In the market, there are plenty of higher-quality replacements. By doing this, you can increase your car price if you ever have plan to resell it.

3. Bad installation
Poor installation is common among customized windshields. If you've planning to have the windshield replaced, they should be sturdy and well-attached. Otherwise, vibrations while traveling could loosen and break it.

4. Accidents
The most prevalent cause of cracks in the windshield is an accident. Accidents can occur in a variety of ways, and the only way to prevent them is to be mindful on the roads.

5. Temperature changes
Your windshield may shatter due to extreme temperatures. All you have to worry about here is the high heat, which can completely destroy your windshield. Try to park your car in a covered spot to avoid this happening. This will reduce the risks of it being exposed to direct sunlight.

 

6. Glass design angle. Obviously the steeper the glass angle the more of a direct hit debris will be against the glass. Less angle can bounce or blow debris off or over a bit easier.

 

These are part of the car design and can't be changed but changing the car, but still important factors.

7. Structural glued windshield. All the twist of the bodywork causes a stress to the windshield, which is intended to stiffen the structure, but it also makes windshield susceptible to cracks.

8. Thin glass. In order to reduce weight, fuel consumption and costs car manufacturers want to decrease glass thickness.

 

Even bigger risk to crack the windshield is remarkable temperature variance within the glass. This can happen if the windshield is cold (like minus degrees Fahrenheit) but engine is warm and all the heat is directed to windshield to defreeze it quickly. Intact windshield will stand it, but if there happens to be an initial crack in unlucky place, it can become a long crack crossing the lower part of the windshield. Very ususal here in Finland.

 

Flying stonechips occur also in winter conditions when the road crossings or hills are sanded. Sometimes tire studs can get airborne too.

 

For my Fit, I dropped a ratchet on mine. Even with a cheapo replacement and a recent 6000+km trip and cold winters, no issues.

 

Following gravel trucks closely is asking for a stone or pebble impact, so is not paying attention to trucks that pull onto a paved road from a gravel road. Large truck tires have wider grooves than light truck and car tires and can store up ammunition only to let them stones fly at highway speeds.

 

Newer cars are being specced with lower strength glass. Starting on luxury brands and working way down. The OEMs I've talked to for work say it's to save weight (mpg) which is just laughable because it's like 2lbs off a Mercedes SUV that weighs 4500lbs ... There may be secondary reasons like accommodating the cameras but that's just a guess. Super irritating. Common on my Subaru outback model for owners to need new glass frequently.

 

Its the gravel trucks or semis that always kick rocks up at me that get me. All good info though, thanks for sharing. Distance seems to be the best prevention method but most times its unprecedented..