Windshield repair vs replacement comes down to three questions: how big is the damage, what kind of break is it, and where on the glass is it? Size gets the most attention, but in practice the location often decides. This guide sets out what the repair standard says, the rules of thumb that technicians use at the car, and the cases where a repair is possible on paper but a replacement is the better choice. Each rule has its source under it, and rules of thumb are marked as such.
The short answer
| Damage | Usually | Why |
|---|---|---|
| A chip smaller than a quarter, away from the edges and out of the driver’s view | Repair | Small and shallow: Impex’s description of what can be repaired |
| A star or bullseye up to two inches across | Repair, if well placed | ROLAGS: stone-breaks up to 2 inches are repairable |
| A single crack of 6 inches or less | Often repair | A short crack under ROLAGS |
| A single crack of 6 to 14 inches | Depends on where it runs | ROLAGS allows single-line cracks up to 14 inches, but placement matters |
| Any crack that reaches the edge | Replace | An edge crack; the edges carry much of the glass’s strength |
| Damage in the driver’s direct view | Usually replace | A repair leaves a mark where you look most |
| Damage in front of the windshield camera | Usually replace | The camera needs clear glass |
| Several breaks, or damage through both layers | Replace | Too much of the glass is weakened |
Ask for a quote
Three short steps: where the damage is, your vehicle and how to reach you. Impex comes back to you with a quote.
Know the kind of break
The shape of the damage tells a technician how the break will behave and how well resin will fill it.
- Bullseye: a round, cone-shaped break with a clear ring around it. It tends to stay put and fills well when small.
- Star break: a small impact point with short cracks, or legs, running out from it. The legs are what spread, so a star break is worth seeing to quickly.
- Combination break: a bullseye with legs, judged by its overall size including the legs.
- Half-moon or partial bullseye: an incomplete ring, usually treated like a bullseye.
- Single crack: a line, usually from an impact point. Judged by its length and where it runs, as below.
When you describe the damage on the phone, saying which of these it looks like, and roughly how big it is next to a coin or a dollar bill, gets you a useful answer before anyone drives out.
What the repair standard says
Windshield repair has its own standard: ROLAGS, the Repair of Laminated Automotive Glass Standard, administered by the National Windshield Repair Division and now published as ANSI/AGSC/NWRD/ROLAGS 002-2022. Its consumer page says that stone-breaks up to two inches in diameter and single line cracks up to 14 inches are repairable. Its definitions sort cracks into three kinds:
- Short crack: six inches (150 mm) or less.
- Long crack: more than six inches.
- Edge crack: a crack that extends to an edge of the glass.
Those figures are the outer limits of what a trained technician can repair. The standard itself sets further limits, including rules about the driver’s viewing area, which are not reproduced here. What matters for you is that the 14-inch figure is a ceiling, not a promise: plenty of damage inside it is still better replaced.
The rules of thumb
At the car, technicians and drivers use quicker tests. Impex describes small chips as those smaller than a quarter. A common industry rule says that if the damage is smaller than a dollar bill, about six inches, it can likely be repaired. Neither is a law or part of the standard. They are useful because they are easy: if the chip is smaller than a quarter and nowhere near the edge, it is very probably a repair; if the crack is longer than a dollar bill, it is time to look carefully at where it runs.
Why location matters more than size
Impex’s own rule is that a repair may be possible if the damage is small, shallow and away from the edges of the glass, and that if the damage is large, deep or reaches the edge, a full replacement is safer because the structural integrity and clarity needed for safety systems may be compromised. Each part of that has a reason.
The edges
The edge of the windshield is where it is bonded to the car, and the bond and the edge together carry much of the glass’s strength. A crack that reaches the edge, or a chip close to it, is in the part of the glass that works hardest. That matters because the windshield is a safety part: the Auto Glass Safety Council says windshield and side glass are part of the passenger restraint system and must be installed properly for airbags to deploy safely, and that the windshield aids in occupant retention.
The driver’s view
A good repair stops a break from spreading and restores much of its clarity, but it does not make it vanish. Out on the passenger side, a faint mark is no trouble. Directly in front of the driver, at eye level, it can catch low sun or headlights at night. Many drivers choose a new windshield for damage there even when a repair is possible.
The camera
On many newer cars a forward-facing camera looks through the glass at the top of the windshield, and it runs lane departure warning, collision braking and adaptive cruise control. Damage in its view, repaired or not, can affect what it sees. A replacement there is followed by a camera calibration; see ADAS calibration.
Can a 12 inch crack in a windshield be repaired?
Google shows this question to drivers in Sanford, and the answer is: sometimes, but usually not. Under ROLAGS a single-line crack of 12 inches is inside the 14-inch limit, so it is not automatically a replacement. But a crack of that length is a long crack, it usually began at an impact point that may itself be large, and it very often runs toward or into the edge, or across the driver’s view. If any of those is true, the windshield should be replaced. A 12-inch crack that is a single clean line, well away from the edge and out of the driver’s view, is the case where a repair is worth asking about. Send a photo and Impex can tell you which you have.
Not sure whether yours is a repair? Call and describe it, or fill in the quote form.
How long can you drive on a cracked windshield?
No North Carolina law sets a time limit, and no statute or inspection rule sets a crack size: the NC safety inspection (G.S. 20-183.3) checks your wipers, not the glass itself. But that is not a reason to wait. A crack weakens part of the car’s restraint system, which the airbags rely on and which helps keep people inside the car in a crash, and chips and cracks grow with heat, cold and rough roads. The sooner a chip is seen, the more likely it is still a repair. A crack in your line of sight is a safety problem from the first day.
Things that push a repair toward replacement
- Time. Dirt and water get into an open break. A chip that is weeks old is harder to fill cleanly than one that is days old.
- Growth. If a chip has grown legs, or a short crack is getting longer, it is moving toward replacement.
- Depth. If you can feel the break from inside the car, both layers are damaged.
- Number. Several chips close together weaken one area of glass.
- Earlier repairs. A chip next to an old repair is harder to fill well.
Repair or replace: what changes for you
| Repair | Replacement | |
|---|---|---|
| Factory seal | Kept | Replaced with a new urethane bond |
| Time | Short, with no adhesive to cure | About an hour plus a short cure (Impex) |
| Camera calibration | Not usually involved | Usually needed on cars with a windshield camera |
| The mark | A faint mark remains | Clear glass |
| Insurance | A comprehensive glass claim | A comprehensive glass claim |
Either way, in North Carolina a glass claim normally falls under comprehensive coverage, less any deductible, and you choose who does the work under G.S. 58-3-180. See glass claims.
What to do next
If your damage looks like a repair, read windshield repair in Sanford, NC. If it looks like a replacement, read windshield replacement in Sanford, NC. Both are done at your car by mobile service in Sanford and across Lee County and nearby.
Sources
ROLAGS repairable sizes: rolags.com/repairable-damage/. Crack definitions: rolags.com/definitions/. Standard name: rolags.com (the full standard’s driver’s-view limits were not read). Quarter rule and repair wording: impexautoglass.com/auto-glass-replacement/ and homepage FAQ. Dollar-bill rule: an industry rule of thumb. Restraint role: agsc.org/proper-auto-glass-replacement/. Camera functions: I-CAR crn-455. Inspection: G.S. 20-183.3.
Questions people ask
Can a 12 inch crack in a windshield be repaired?
Sometimes. ROLAGS allows single-line cracks up to 14 inches, but a 12-inch crack that reaches the edge or crosses the driver’s view should be replaced.
How big a chip can be repaired?
ROLAGS says stone-breaks up to two inches in diameter. As a rule of thumb, a chip smaller than a quarter is a small chip.
Is windshield repair worth it?
For a small, shallow chip away from the edges, usually yes: it stops the break spreading and keeps the factory seal. It leaves a faint mark, so damage in the driver’s view is often better replaced.
Is there a crack-size law in North Carolina?
No. NC has no statute or inspection rule setting a crack size; the safety inspection checks wipers, not the glass. A crack in your line of sight is still a safety problem.
Questions about your glass?
Call and talk it through, or get a quote with the form on this page.