Windscreen Chip Repair or Replacement: When Can a Chip Be Fixed?

How a windscreen is built and why that matters

A windscreen is laminated glass: two layers of glass with a clear plastic film bonded between them. That film is why a stone usually chips the outer layer without the whole screen shattering, and it is also why a chip can often be repaired. The damaged area is cleaned out and filled with a clear resin, which is then cured so it hardens and bonds with the glass around it.

The repair is mainly about stopping the damage from spreading and restoring strength. It will usually make the chip far less noticeable, but it will not make it vanish completely, so a faint mark may remain. That is normal and is not a sign of a poor job.

Size, type and depth of the chip

Small, clean chips are the likeliest candidates for windscreen chip repairs. Bullseyes, star breaks and small combination breaks are the usual types that can be filled. A chip that has gone right through to the inner layer, or one with a long crack leaving it, is much less likely to be suitable.

Dirt matters too. A chip that has been open for weeks collects road grime, moisture and washer fluid, and that contamination can stop the resin bonding properly. This is one of the biggest reasons the advice is always to get it looked at quickly.

• Small bullseye or star chips are normally the easiest to repair
• Cracks running out from the chip reduce the chances of a repair
• Damage that reaches the inner layer usually points to replacement
• Chips close to the edge of the glass can weaken the screen and may need replacement
• A dirty, long-standing chip is harder to repair cleanly

Position and the driver's line of sight

Where the chip sits can matter as much as how big it is. Damage directly in front of the driver is treated more strictly, because even a neatly repaired chip can leave a slight distortion or glint that catches the eye, particularly in low winter sun or at night with oncoming headlights.

Chips near the edge of the screen are a separate worry. The glass is under more stress there, and a crack can start and run quickly. Many cars also have cameras and sensors fixed behind the windscreen, and damage in front of those can be a reason to lean towards replacement. What can be fixed is always a judgement made on inspection, so we would rather look at it than guess from a description.

When windscreen replacement is the sensible route

Replacement makes sense when the damage is too big, too deep, too close to the edge or in a spot where a repair would compromise your view. It is also the answer when a chip has already turned into a long crack, because filling a crack that long rarely holds it.

A windscreen is part of what holds the car's structure together and helps the airbags work properly, so the new glass has to be fitted and bonded correctly. At Banks of the Tyne in Hebburn we handle windscreen repairs and windscreen replacement, along with side and rear glass, so you will be told straight which one your car needs.

Act quickly and protect the chip

A chip can sit quietly for weeks and then spread across the glass overnight after a cold snap, a hot day, a pothole or a slammed door. Temperature swings put the glass under stress, and a damaged spot is where it gives way first.

Until you can get it seen, keep the area clean and dry. If the chip is fresh, a piece of clear tape over the outside can keep dirt and moisture out. Avoid blasting it with a jet wash, and go easy on the heater and demister settings.

• Do not pick at the chip or push anything into it
• Avoid slamming the doors while the damage is there
• Keep hot air from the demister off the damaged spot at full blast
• Get it inspected soon, even if it looks tiny

Frequently asked questions