A typical automobile windshield is made up of at least two layers of glass with a polymer resin between them. This gives the glass strength, and in the event of an accident, the resin is designed to hold the pieces of glass together and stop the glass from shattering and causing injury.

Because of the layered structure of a windshield, a chip repair is possible. Usually in the event of a stone chip, only one layer of glass is damaged, with the underlying layers remaining undamaged. This means that it is possible to make the windshield more stable, and prevent the damage getting any worse, without having to replace the whole windshield.

If the stone chip has gone through more than one layer of the glass, or is positioned right in the centre of the driver's field of vision, then you should consider replacing the wind shield completely, because under such circumstances, the damage could cause impairment to the ability of the driver.

If the windshield is repairable, you should carry out the work as soon as possible after the damage occurs. If it is left too long, the cracks can spread out across the glass due to the pressure of the air against the glass while driving. As the cracks spread, the glass becomes weaker and weaker, and can eventually simply shatter under the pressure.