As temperatures start to rise, one of the most common questions we hear at this time of the year is whether a car wash can actually crack a windshield…
The short answer is no, a car wash, on its own, does not cause a windshield to crack. Understanding what actually causes windshield damage can help you avoid unexpected repairs and make informed decisions before your next wash. Windshield damage is not always straightforward, and in many cases, the cause is related to existing conditions in the glass combined with environmental factors such as temperature.
How Weather Change Can Affect Your Windshield
When there is a sudden change in temperature, any existing chip or imperfection on your windshield can worsen and potentially lead to a crack.
These chips are not always easy to see. They are often hidden under the wiper area or close to the window molding, which means many drivers are unaware that their windshield is already compromised.
Hot weather increases this risk. Even if your vehicle is parked in direct sunlight, a small chip can expand into a crack without warning. When combined with a change in temperature, the likelihood of damage increases further.
Watch this temperature test by industry experts Scott Harkey of Windshield Glass, with over 20 years of experience, alongside Pat McCain from McCain Auto Glass, who also brings more than two decades of hands-on experience in the industry:
Understanding Stress Cracks
In addition to visible chips, windshields can also develop what are known as stress cracks.
Stress cracks occur due to internal tension within the glass rather than direct impact. They often do not have a visible point of origin and may begin at the edge of the windshield or at a naturally weaker area.
Once a stress crack begins, it can spread quickly. Sudden temperature changes- such as a warm windshield coming into contact with cooler water, or the use of heat or air conditioning can contribute to the stress crack.
Existing Structural Stress in the Windshield
Windshields are constantly under tension due to the structure of the vehicle. This is part of normal vehicle design and helps maintain overall strength and safety.
However, this also means that if the glass is already weakened, even normal movement—such as driving or passing through a car wash—can be enough to cause that weakened area to expand into a crack.
So Can Car Wash Cause a Crack in the Windshield?
It is important to understand that a car wash alone does not cause a windshield to break. However, if there is a pre-existing chip, stress point, or internal weakness in the glass, the combination of temperature change and normal vehicle movement can result in a crack appearing during the wash.
According to guidance from the International Carwash Association, the presence of pre-existing damage is the root cause of windshield cracks, while environmental factors—such as temperature change—contribute to the timing of when the crack occurs.
What You Should Do to Prevent Windshield Cracks?
We strongly recommend inspecting your windshield regularly, especially during periods of hot weather.
If you notice a chip or any sign of damage, we suggest you avoid using the car wash until you have it repaired at a glass shop. In most cases, chip repairs are covered by insurance, and there is no cost to you as the deductible is waived. However, once a crack appears, the windshield will need to be replaced. Addressing a chip early can prevent it from turning into a larger crack that requires full windshield replacement.
For more information, please read this Special Alert issued to all Car Washes from the International Carwash Association:
