Glass will always behave in several predictable ways. Your windshield is no different inasmuch as you can pretty much predict what will happen under certain circumstances. Cold weather causes the glass to contract and the variance between the temperatures
on the inside layer of the windshield versus the temperature on the outside, can easily cause the windshield to crack.
- Glass expands in the heat and contracts in the cold
- The size of the rock chip does not determine how stable the damaged area is.
- Left un-repaired, it is not a question of whether the damage will expand, it is a question of when.
- If you’v ever experienced accidentally breaking a glass when you held it under water whose temperature was either too hot or too cold, you already know that if you hold a hot glass under cold water, or visa versa, it is going to break. This is because the variation in temperature causes the glass to either expand or contract, and to relieve the pressure, the glass cracks. This is exactly what happens to your windshield. When your windshield is damaged from a rock, it is already unstable. If you run your car heater in the colder weather, or if you run your car air condition in the warmer weather, you are setting up the same conditions as running a glass under water of the opposite temperature. To relieve the pressure, your windshield will crack, resulting in the need for a costly replacement.
- The size of the rock chip has little to do with whether the damage will spread. Drivers are lulled into thinking that because the damage is small, it is unlikely to grow in size. This couldn’t be more wrong. I can’t tell you the number of times a customer’s story starts out with, “it was such a small, little rock chip, and then suddenly, without any warning, we came out to the car to find it had grown into a 9″ crack.” The windshield is unaware of the size of the damage. The laws of physics are all that applies here. It is simply this: Damage of any size, will eventually grow and spread to the place on your windshield with the least amount of pressure. You can count on it.
- Most drivers think that because a rock chip that occurred months, or even years ago, has not spread, that it will never cause a problem. Again, this couldn’t be more wrong. If you don’t treat the rock chip, regardless of how long you’ve gotten away with it not spreading, it eventually will grow in size. it isn’t a question of “if” it is a question of, “when.”