How Heat and Cold Can Crack Your Windshield

Imagine you step into your car on a cold day and turn on the defroster, only to see your windshield cracking. Or you park your vehicle in the sunlight on a sunny day and see a new crack on your windshield. What would you do afterwards? Either you can drive it to work or go to a shop that provides auto glass repair services to fix the windshield.

But what if the same happens to you again? What if your windshield develops cracks again? To ensure you don’t face such issues repeatedly, you must understand how heat and cold can crack your windshield. If you want to learn how heat and cold affect your windshield, please read this blog now!
How Heat and Cold Can Crack Your Windshield

To understand how heat and cold can crack your windshield, you must understand the glass expansion and contraction. Here’s what you need to know about thermal expansion and contraction:

• Thermal Expansion: When glass gets hot, its molecules gain energy and vibrate more. This increased vibration makes the molecules spread apart, which causes the glass to expand.
  
  
• Thermal Contraction: When the glass cools down, the molecules lose energy and vibrate less. This decrease in vibration allows the molecules to move closer together, causing the glass to contract.

These two natural processes become problematic when they happen too quickly or unevenly, leading to stress and cracks on your windshield. For instance, when the glass is too hot and you try to cool it down, it contracts faster and develops cracks. On the other hand, if you try to heat a too-cold windshield glass, it expands faster, causing cracks on your windshield.
Tips to Protect Your Windshield from Heat and Cold Cracks

If your vehicle’s windshield has cracked and you are worried that it might happen later, follow these tips to protect your windshield:
Avoid Temperature Shock

Warm your windshield using a moderate defroster if it’s too cold outside. And if it is too hot outside, cool your windshield with moderate air conditioning settings. One mistake most people make during winter and extreme cold temperatures is using too hot water to defrost the ice on their windshield.

This may look like a shortcut or an easy way to defrost, but it is not, as it can shatter the windshield or cause cracks if it is laminated glass. And you don’t have to make this mistake. Always use lukewarm water to de-ice your windshield in winter.
Park Smart

To protect your car’s windshield during extreme temperatures, park your car smartly. For instance, try to park your car in the shade with windows slightly open during summer. Doing so will prevent heat buildup in the cabin and won’t let the windshield reach an extremely high temperature.

During winter (snow), one should park their vehicle in the garage if possible. However, if there is no garage, park your vehicle with a windshield cover to protect your car from snow. A windshield cover will prevent your windshield from reaching a freezing temperature and cracking when warming up, thus saving money on windshield replacement.
Repair Damage Promptly

If your car’s windshield has been damaged (i.e., cracked or chipped), fix the damage as soon as possible. Doing so will prevent them from spreading due to thermal stress. Also, repairing the damages will keep you and others safe on the road. During the collision, the cracked windshield might not withstand the impact, ejecting the passengers without a seatbelt out of the car. So, don’t delay repairing your cracked/chipped windshield. Get it done without delay!
On the Final Note

Sometimes, the car’s windshield can crack without any obvious reasons, for instance, while defrosting or cooling down your cabin. It happens due to thermal stress, and when it occurs, it may make you wonder what exactly has caused it. Now, you might be familiar with why it happens. To protect your car’s windshield from such incidents, try to park your car in the shade during summers and in a covered area like a garage during winters. More such tips on protecting your windshield during extreme temperatures are mentioned above in this blog.