Can Car Washes Make a Windshield Crack Worse?

Written by: Adam Cote

Understanding the Risks, Causes, and Best Practices for Vehicle Owners

A cracked windshield is more than just an eyesore—it’s a safety hazard. If you’ve recently noticed a chip or crack in your glass, you might be wondering: Can a car wash make my windshield crack worse? The short answer: yes, it can—depending on the severity of the crack and the type of car wash. This guide breaks down why it happens, how to prevent further damage, and the safest steps to take.

Why Car Washes Can Make Windshield Cracks Worse

Windshields are made of laminated safety glass, which is strong but not immune to stress. Once a crack or chip exists, certain forces in a car wash can accelerate the damage.

1. High-Pressure Water Jets

Automatic and self-service car washes often use high-pressure nozzles to blast away dirt. If water hits directly into a crack, it can force debris deeper into the glass or increase pressure around the damaged area—causing it to spread.

2. Sudden Temperature Changes

One of the most common culprits for worsening cracks is thermal shock. For example:

  • On a hot day, cold water from a car wash can rapidly cool the windshield surface, stressing the glass.
  • On a cold day, warm water or air dryers can cause uneven expansion.
    Both scenarios increase the likelihood of the crack spreading.

3. Mechanical Brushes and Vibrations

While soft-touch brushes are designed to be gentle, the repeated mechanical contact combined with vibrations from the conveyor track can cause a crack to extend—especially if it’s already near the edge of the windshield.

Types of Car Washes and Their Impact on a Cracked Windshield

Not all car washes are equal when it comes to cracked glass.

Touchless Car Washes

  • Pros: No brushes, less direct mechanical force.
  • Cons: Still uses high-pressure water jets, which can worsen cracks.

Soft-Touch Automatic Washes

  • Pros: Less pressure compared to touchless jets.
  • Cons: Brushes can jolt the glass and flex the windshield slightly.

Hand Wash

  • Pros: Gentle and controlled, minimal stress on glass.
  • Cons: More time-consuming, but safest for damaged windshields.

Common Questions About Windshield Cracks and Car Washes

Will a small chip spread in a car wash?

Yes—especially if water pressure, temperature shifts, or vibrations occur. Even tiny chips can grow into large cracks under stress.

Can I go through a car wash with a repaired crack?

If the crack has been professionally repaired and sealed, most car washes are safe. However, it’s best to wait at least 24–48 hours after repair to allow the resin to fully cure.

Do car wash soaps damage windshields?

No—detergents won’t cause cracks. The issue comes from physical stress, not chemical erosion.

Is it illegal to drive with a cracked windshield?

In many states and countries, yes—if the crack obstructs your vision or exceeds certain size limits. Check your local laws.

How to Prevent Windshield Damage in a Car Wash

  • Choose a hand wash or low-pressure rinse method.
  • Avoid extreme temperatures—wash during moderate weather.
  • Inspect your windshield first and avoid washing if the crack has grown.
  • Repair chips immediately to prevent them from spreading.

Why You Should Repair Your Windshield Before Washing

Windshield cracks rarely stay the same size. Driving, temperature changes, and vibrations naturally make them worse—and car washes can accelerate that process. Repairing the glass early:

  • Restores structural integrity.
  • Prevents costly full windshield replacements.
  • Improves visibility and safety.

Final Verdict

Yes—car washes can make a windshield crack worse due to water pressure, temperature changes, and mechanical vibrations. If your windshield is damaged, skip the automatic wash and opt for a gentle hand wash until you get it professionally repaired.

By addressing cracks early, you protect your safety, preserve your vehicle’s value, and avoid turning a small repair into an expensive replacement.

Ready to Protect Your Investment?

About the Author

Picture of Adam Cote

Adam Cote

Adam Cote is a veteran of the automotive protection industry with decades of experience in ceramic coatings, paint protection films, and window tint technology. As Director of Product Development at Ceramic Pro, he oversees the creation and testing of industry-leading products, ensuring they deliver unmatched durability, performance, and aesthetics. Widely respected for his technical expertise and innovation, Adam continues to set new standards in vehicle surface protection.

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