When dealing with damage to a windshield or another piece of auto glass, there is always the question of whether repairs can be done or if it's time to go for a full-on replacement. If you're in such a situation, here's what you need to know before you contact a glass repair services provider.
A rough rule of thumb is that almost any type of damage you can cover with a quarter may be repairable. Some cases may be repairable with damage up to 18 inches in length. Bear in mind, though, that some of the following factors may make glass repair a less likely option even if the size is small.
Location, Location, Location
Proximity to anything important reduces the chances you can have repair work done. The most important location is anything within one inch of the edge of the windshield. Even if the crack or chip is otherwise innocuous, it's not worth the risk and most technicians won't touch it.
Similar concerns now occur with sensors that are located in or near the glass. You may also lose some functionality, such as when damage hits the heating elements in the rear defroster system.
Another source of concern is how complex the damage is. Simple chips and radial cracks are generally easy to fix as long as they're under a couple of inches in diameter. Bullseye cracks that radiate outward can be a bigger issue, but they may be repairable if under an inch in diameter. Complex cracks, however, usually should lead to the replacement of all the glass. If it's evident that the underlying laminates have been damaged by a deep pit or gouge, that's probably also a replacement job and not a glass repair.
Once a windshield has sustained three or more visible cracks, it's time to replace rather than fix. Be aware this includes previous damage that has been made invisible by glass repair work counts toward your total.
Anything in the Line of Sight
Put your car's visor down. Take your hands from your car's steering wheel and draw a line straight upward with each hand until you hit the visor. Any damage that's in that zone should not be repaired, and you should instead replace the glass. Any distortion in this area is a threat at highway speeds. Note though, that means the vast majority of damage occurs in zones where glass repair is still a reasonable option.