Windshield damage identifier
The short answer
- Break shape is the first thing a technician reads, because it predicts repairability, fill difficulty and how likely the damage is to run.
- The single most useful distinction is whether there is an impact point. No impact point means a stress crack, which is not repairable and may point to an installation or glass defect.
- Bullseyes and half moons repair the cleanest. Star and combination breaks repair well but need a proper vacuum cycle to avoid a cloudy result.
- Any crack touching or within about two inches of the glass edge is a replacement, whatever its shape.
- Widespread pitting and haze is wear, not damage, and no repair addresses it.
Three questions get you to the right name for your damage, and the name tells you most of what you need to know about repairing it. Look at the glass from outside in daylight, then use a flashlight held at a low angle to pick up hairline legs you would otherwise miss.
The eight patterns
How to look at your own glass properly
Most people misread their damage because they look at it once, from the driver's seat, in flat light. Do it this way instead. Park in shade, not direct sun. From outside, run a fingernail across the impact point: if it catches, there is a pit, and there is an impact origin. Hold a flashlight at a shallow angle across the glass and look for hairline legs, which are nearly invisible head on and obvious in raking light. Then put a piece of white paper behind the glass, inside the car, and look again: the paper turns a faint crack into a visible line.
Two measurements matter after that. Diameter, compared to a US quarter, which is the traditional repairability threshold. And distance to the nearest glass edge, measured to the visible glass edge under the moulding, not to the black painted frit border, which extends inward and makes the edge look closer than it is. Anything within about two inches of that true edge is edge damage and is handled as a replacement.
Why the shape matters more than the size
Shape tells a technician how the energy went into the glass, and that predicts how resin will behave in the cavity. A bullseye is a clean conical separation between the ply and the interlayer with an open path from the pit, which is why resin fills it evenly and the result is nearly invisible.
A star break is a set of narrow legs with air trapped at the tips, which is why it needs a real vacuum cycle before pressure: without it, the air stays, and you get the cloudy leg that people complain about. That difference is the entire argument against cheap kits on star breaks, covered in how repair kits actually work.
Shape also predicts spread. Legs are stress concentrators, so star and combination breaks run more readily than bullseyes under a temperature swing. If your identification came back as either of those, treat it as time sensitive and read will a crack spread for the risk factors and what to do while you wait for the appointment.
Once you know what you have, take it through the repair or replace checker, which applies the size, edge, depth and location rules on top of the shape.
Frequently asked questions
What is the difference between a star break and a combination break?
A star break is legs radiating from the impact point with no significant cone. A combination break has both: a round bullseye or half moon plus star legs. Combination breaks are the most common highway stone strike and repair reasonably well when fresh.
How do I know if it is a stress crack?
Look for the impact point. A stress crack has none: no pit, no cone, no starburst. It typically starts at the edge and appears after a temperature swing or a hard flex. If there is no pit anywhere along the crack, treat it as a stress crack.
Does the shape change the price?
Not much for repair. Most shops charge one price per chip regardless of type, $60 to $150 for the first. Shape changes the odds of a clean result, and it changes whether a repair is offered at all.
What if my damage matches two patterns?
Then it is probably a combination break, or two separate impacts close together. Treat the more severe pattern as the governing one, and note that multiple breaks close together push the decision toward replacement.