Stone Chip Repair or Replace the Windscreen?

Start with where the stone came from

Arrive Alive names flying stones and debris from the loads of commercial trucks, and material thrown up from roads under construction, as the most common cause of windscreen damage. Anyone who drives the N1 or N4 around Pretoria behind a loaded truck knows the sound. Potholes add to it: Rekord has reported on Tshwane's pothole repair programmes in Pretoria North and residents' long waits for repairs, and rough roads put extra stress on damaged glass.

The good news is that a stone usually damages only the outer layer of the laminated windscreen. If it is dealt with early, that damage can often be filled.

Test 1: size

The common industry rule of thumb is that a chip smaller than a five-rand coin can usually be repaired. Put a coin next to it as a quick check, then take a photo with the coin in shot. That photo is useful for the fitter and for an insurer.

Size alone does not decide it. A small chip in the wrong place may still need a new screen, and a slightly larger bullseye with no cracks may be within one fitter's limits but not another's.

Test 2: position

Position matters as much as size. Even a good resin repair leaves a faint mark, and the resin bends light slightly differently from glass. In the area directly in front of the driver, that can create a small distortion right where your eyes need to be clear. Many fitters will not repair in that zone for that reason.

Two other positions are trouble. Near the edge of the glass, stress is higher and a chip is more likely to run into a crack. In front of a camera window behind the mirror, resin can affect what the camera sees, so a replacement with calibration may be the safer route.

Test 3: cracks running from the chip

A chip that has started to grow legs is on its way to becoming a crack. A very short leg caught early may still be repairable. A crack that is already long, that is still spreading, or that has reached the edge, means the screen's strength is compromised and a replacement is usually the honest answer.

If you can feel damage on the inside of the glass as well as the outside, both layers are affected. That is beyond a resin repair.

Test 4: time

A fresh chip is the easiest to repair. Over days and weeks, dust and water work into the break, which stops resin from filling it cleanly and leaves a more visible mark. Every temperature swing also works on it: a cold front on the Highveld, a hot car hit by cold rain, or a blast of aircon on sun-baked glass.

The practical rule is to treat a chip as urgent but not as an emergency. Cover it with clear tape, avoid aiming the demister or aircon at it, and arrange a repair within days rather than weeks.

A quick decision guide

Probably repairable: one fresh chip, smaller than a five-rand coin, outside the driver's view and away from the edge.
Ask the fitter: a chip with one short leg, two chips some distance apart, or a chip near the camera area.
Probably a replacement: a crack longer than a few centimetres, damage at the edge, damage in front of the driver or on both layers of glass.
Definitely a replacement: shattered or caved-in glass, or a screen that is leaking or separating at the edges.

Legal is not the same as safe

Arrive Alive notes that the National Road Traffic Act does not make it illegal to drive with a crack outside the driver's view. But the regulations require the windscreen to be safety glass that still lets the driver see clearly, and a cracked screen is weaker. The windscreen helps support the roof in a rollover and backs up the passenger airbag, so its strength matters most at exactly the moment you hope never comes.

What happens if a repair does not hold

Resin repairs are reliable on the right chips, but not guaranteed. If a repaired chip later cracks, the screen needs replacing. Ask the fitter up front what happens in that case and whether any of the repair cost counts towards a replacement. [CONFIRM: what workmanship cover fitment businesses covering Pretoria give on chip repairs]

On insurance, many insurers pay for chip repairs, often with little or no excess, because a repair costs them far less than a new screen. See our guide to windscreen insurance claims. To arrange a repair, start at windscreen chip repair in Pretoria or a local page such as chip repair in Montana or chip repair in Garsfontein. If it has gone too far, see windscreen replacement.

Frequently asked questions

How do I know if my windscreen chip can be repaired?

As a rule of thumb, a fresh chip smaller than a five-rand coin, outside the driver's view and away from the edge can usually be repaired. A fitter makes the final call.

Can a long crack in a windscreen be repaired?

Usually not. Long or spreading cracks, and cracks that reach the edge, generally mean the screen must be replaced.

Why should I repair a chip quickly?

Fresh chips fill more cleanly. Dirt, water and temperature changes make an old chip harder to repair and more likely to spread into a crack.

Is it illegal to drive with a chipped windscreen?

Arrive Alive notes that a crack outside the driver's view is not automatically illegal. It is still weaker than an undamaged screen, so have it checked.

Will a repaired chip be invisible?

Usually not completely. A faint mark often remains. The aim is to restore strength and stop the damage spreading.

Stone chip repair or full windscreen replacement?