Your car's windshield protects you from debris and keeps the wind from blowing in your face. However your windshield is not invincible, and cracks and chips can happen. Large cracks affect the integrity of your windshield, so it's important to prevent and repair them as much as possible. Here are some of the most common reasons why your windshield will crack and what to do if it happens to you.
Hit by Debris
One of the most common ways that windshields get cracked is by being hit by a flying rock or wind-blown debris. Large trucks can easily kick up small rocks that can crack your windshield in a second. Reduce your risk by keeping your distance from other vehicles and keeping an eye out for, and avoiding, flying objects. You should also limit your driving during hail storms.
Poor Sealing and Installation
If your windshield was not set and sealed correctly, then it could lead to cracking. This is more likely with an aftermarket windshield, but can also happen with factory-installed ones as well. Poorly installed windshields can vibrate excessively and that can cause cracks. If you have "bargain" windshield glass installed, cracks are more likely to happen even if it was installed correctly.
Severe Temperature Changes
Your windshield contains more than one layer of glass. Large temperature changes between the inner glass layer and the outer glass layer could result in cracking. For example, your windshield will crack if the outer layer gets extremely cold and the inner layer is extremely warm, or vice versa. This is why you should never pour hot water on a cold windshield to remove ice because that causes a sudden temperature change.
Large Stress and Pressure Changes
Most properly installed windshields are well designed to hold up to pressure problems and stress. However, some conditions can cause extreme pressure on your windshield. For example, if you drive into a very hard head wind, then that could create enough pressure to cause cracks. The same goes for if you drive your passenger car at extreme speeds.
Usually, small chips and cracks less than a quarter in size can be left alone or fixed with glass repair kits. Even if the crack is small, don't think that you won't have any more problems. Small cracks can worsen if your windshield gets hit again or suffers from stress and vibration. Cracks over a certain size will get you a ticket in many areas of the country. If you have a large windshield crack, see an automotive glass company for windshield repairs.