Cracks in the windshield are not just a visual flaw—they are also a safety hazard. If you notice cracks or chips on the glass, you might wonder: will washing my car make the windshield crack worse? The short answer is: yes—it depends on the severity of the crack and the type of car wash. This article will explain why this happens, how to prevent further damage, and the safety 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. 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
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 small chips spread when washing the car? Yes—especially when there are changes in water pressure, temperature, or vibrations. Even tiny chips can develop into larger cracks under pressure. Can you wash the car after a crack has been repaired? If the crack has been professionally repaired and sealed, most car washes are safe. However, it is best to wait at least 24–48 hours after the repair to allow the resin to fully cure. Will car wash soap damage the windshield? No—the cleaners do not cause cracks. The issue is physical stress, not chemical corrosion.
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 Recommendation
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.