Repairing Rock Chips in the Windshield

A chip in a windshield.

Did you know that unsightly rock chip in your windshield can be repaired? As long as it’s not in the direct line of sight of the driver in the portion of the windshield known as the critical area, it may be repairable. If so, repairing a windshield instead of replacing it will save you hundreds of dollars. In many cases, it may even be free.

The Basics

Windshields are made of glass, so it’s important to keep your expectations reasonable and understand the facts about windshield repair. Always remember three important facts: Glass is fragile. Glass breaks. Windshield repair technicians need to drill into the glass.

The windshield repair technician first drills into the rock chip, applies vacuum, then injects a resin into the rock chip. The resins used to repair windshield rock chips are optically compatible with glass. Once the resin is injected, the technician uses an ultraviolet light to cure it. He then scrapes any excess resin from the windshield and cleans the glass. The repair is now complete and the windshield is no longer in danger of cracking further from the point of impact.

Possible Further Damage

crack in a windshield

The possibility that the rock chip will crack further during the repair process is a very real one. Most companies apply the cost of the repair to a replacement windshield if this happens. While it may cross your mind that the auto glass replacement company wants this to happen, this isn’t necessarily so. The profit margin on windshields has eroded due to a combination of intense local competition, cheap imported windshields, and insurance pricing agreements with insurers. A windshield repair, however, is quite profitable, and can be completed in less than a half hour.

If the windshield survives the repair, be prepared to see a blemish where the rock hit the windshield. The windshield repair is meant as a structural repair rather than a cosmetic one. Consider any improvement in appearance a bonus. Most will look much better than before the repair, but due to dirt and debris that may have collected in the cracks and the nature of the resin used, it may still be visible.


If a rock hits your windshield, immediately cover it with clear tape to keep it clean and dry. Avoid extreme temperature changes, and car washes until you can get it repaired. These are all conditions that cause further spreading. And finally, check with your insurance; in most cases the insurance company waives the deductible for a windshield repair, costing you nothing to repair the windshield.

In general, the sooner the repair is done, the better the results will be because less dirt, debris, and moisture will have settled in to the chip. Smaller rock chips will turn out better than larger ones, as well as those with shorter cracks radiating out.