Not every chip or crack means a full windshield replacement. Prompt auto glass chip repair can often restore a windshield's strength and clarity in about half an hour, for a fraction of the cost of replacement, if it's caught before it spreads. Here's how technicians decide, including for drivers researching auto glass chip repair in London, ON.
Common Types of Windshield Damage
Common types of windshield damage include:
- Bullseye: Circular chip, dark centre; usually the easiest to repair.
- Star break: Short cracks radiating from one impact point.
- Combination break: A bullseye and star break together.
- Half-moon: A partial, semi-circular bullseye.
- Short crack: Thin line, generally under 15 cm.
- Long or edge crack: Runs across the glass or starts near the border.
Stress crack: No impact point; from temperature swings or a glass weak spot.
Repair or Replace? Size, Depth, and Location
Technicians weigh three factors. Size: chips smaller than a quarter and cracks under roughly 15 cm are generally good repair candidates. A rule of thumb, not a legal cutoff, is reflected in the Repair of Laminated Automotive Glass Standard (ROLAGS), the North American reference for windshield repair. Depth: a windshield is laminated glass, two layers bonded to a plastic interlayer.
Repair involves injecting resin into the damaged outer layer; if the break extends to the inner layer, replacement is safer. Location: damage in the driver's sightline is usually not repaired even when small, since a repair can leave slight distortion right where it's noticeable. Edge damage is treated cautiously too, since that area carries more structural stress.
Quick Decision Checklist
Repair is usually possible when the chip is quarter-sized or smaller, the crack is under 15 cm, it's away from the sightline and edge, only the outer layer is affected, and it's one isolated point of damage.
Replacement is generally needed when a crack exceeds ~15 cm or continues to spread, several cracks intersect, damage is in the critical viewing area, the break reaches the inner layer, or a prior repair has failed.
These are guidelines, not fixed rules; a technician makes the final call based on the glass and exactly where the damage sits.
Why Windshield Damage Shouldn't Wait
Temperature swings, road vibration, and pothole impacts can turn a repairable chip into a full crack within days, a real factor across Southwestern Ontario winters. There's a legal angle too: Section 74(1) of Ontario's Highway Traffic Act requires a clear driver's view through the windshield, and officers have discretion to act on damage that interferes with visibility. Similar damage can result in a Safety Standards Certificate inspection failing, which is required when transferring ownership of a used vehicle in Ontario. Beyond legality, an intact windshield supports airbag deployment and helps resist roof collapse in a rollover.
ADAS Calibration and Newer Vehicles
Many newer vehicles use a forward-facing camera near the rearview mirror as part of an Advanced Driver Assistance System (ADAS), the tech behind lane-departure warnings and automatic emergency braking. A chip repair doesn't disturb this camera, so calibration usually isn't needed. Replacement is different: the camera is removed and remounted, and a shift of a few millimetres can change how it reads lane markings and distance. Most manufacturers require recalibration, static, dynamic, or both, after any windshield replacement on an ADAS-equipped vehicle.
How a Chip Repair Works
- Assess the damage for size, depth, and contamination.
- Clean loose glass and debris from the break.
- Inject resin into the damage under vacuum pressure.
- Cure and polish with UV light, flush with the surrounding glass.
Most repairs take about 30 minutes, often performed on-site by mobile service.
Common Mistakes to Avoid
Waiting to see if it "gets worse." Delay almost always raises the odds of needing full replacement.
Treating tape as a permanent fix. It keeps out dirt short-term but isn't a repair.
Using a DIY kit on a crack. Kits suit small chips, not cracks, and can trap air that complicates a later repair.
Skipping ADAS calibration. On a camera-equipped vehicle, this isn't optional for safety.
Expert Tips
- Get chips assessed within a few days, before temperature or road vibration turns a repair into a replacement.
- Keep clear tape in the glovebox to cover a fresh chip until it's looked at.
Avoid pointing hot defrost air at a cold, cracked windshield; the rapid change can extend a crack instantly.
Pros and Cons of Repair vs. Replacement
Repair: Pros: lower cost, faster, often no deductible, no recalibration needed. Cons: only suits certain damage; a faint mark may remain.
Replacement: Pros: works regardless of size or location. Cons: higher cost, longer appointment, and ADAS calibration is usually required.
Repair vs. Replacement at a Glance
| Factor | Repair | Replacement |
| Chip size | Smaller than a quarter | Larger than a quarter |
| Crack length | Under ~15 cm | Over ~15 cm, or spreading |
| Location | Outside sightline | In sightline or at the edge |
| Cost | Lower; often no deductible | A higher deductible may apply. |
| Time | About 30 minutes | 60–90 minutes, plus cure time |
| ADAS calibration | Not usually required | Often required |
Mobile Auto Glass Chip Repair in London, ON, and Beyond
Because damage spreads with time, a fast assessment beats a trip across town. Quick Chip Auto Glass offers mobile auto glass London, ON, coming to a home or workplace instead. The same mobile glass repair reaches Windsor, ON, and Southwestern Ontario, including Kitchener, Waterloo, and Guelph.
Booking Auto Glass Chip Repair in London, ON
Booking starts with a description of the vehicle and damage, a quote or insurance check, and then a scheduled mobile visit. Most work carries a workmanship warranty, which is worth confirming beforehand.
Final Word
A chip smaller than a quarter, away from the edge and sightline, is usually a straightforward repair if caught before it spreads. Once damage crosses into replacement territory, doing it properly, with correct ADAS calibration where needed, matters as much as doing it quickly. Quick Chip Auto Glass offers mobile auto glass chip repair in London, ON, and mobile glass repair Windsor, ON, backed by a lifetime warranty on workmanship. Get a free quote, and a technician will come to you.
Frequently Asked Questions
Q. Can a repaired chip be repaired again if it cracks?
Generally no. Once resin has cured in a chip, that spot has reached its structural limit, so a repeat crack usually means replacement rather than a second repair.
Q. How quickly should a chip be looked at?
Within a few days. Temperature swings and everyday road vibration are what turn a small, repairable chip into a spreading crack, so the sooner it's assessed, the better the odds of a simple repair.
Q. Will insurance cover the cost?
Many Canadian comprehensive policies cover chip repair with no deductible, since a small repair now costs insurers less than a replacement later. Confirm coverage with the insurer or shop first.
Q. Can a vehicle be driven with a cracked windshield in Ontario?
It depends on size and location, with sightline damage drawing the most scrutiny. The Highway Traffic Act requires a clear driver's view, and officers have discretion to act on damage that interferes with it. The same crack can also fail a Safety Standards Certificate inspection at ownership transfer.
Q. Does every replacement need ADAS calibration?
Only vehicles with a windshield-mounted camera or related sensors can be confirmed by the technician by make, model, and year. Calibration may be a static in-shop process, a dynamic road test, or both, depending on the manufacturer.
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