Is It Time for a New Windscreen?
Not all windscreen damage calls for your windscreen to be replaced. Many windscreen chips and cracks can be repaired without affecting the integrity of the windscreen, or your safety while driving. But if you’ve ever taken your car in to have a chip or crack repaired only to be told repairs are not possible and the whole windscreen needs to be replaced, you could still be wondering how this is determined.
Reputable autoglass replacement and repair service providers aren’t making random choices to repair or replace. Instead, they are acting according to guidelines set out in Australian New Zealand Safety Standard AS/NZS 2366.1-1999 with specific criteria regulating when a windscreen chip or crack can be repaired.
Where Is the Chip or Crack Located?
Your windscreen is split into two sections: the Critical Vision Area (CVA) is a section the width of the steering wheel, extending from the top to the bottom of the windscreen immediately in front of the driver, and the Primary Vision Area (PVA) is the rest of the windscreen. Chips and cracks within the CVA have different criteria controlling whether they can be repaired or require the windscreen to be replaced. Additionally, cracks that start and end at the edge of your windscreen also limit whether a repair is possible.
The Size of the Chip or Crack
A crack cannot be longer than 25mm when situated in the CVA, and 100mm outside the CVA. Chips, however, are divided into four primary types, with each type having different size limits depending on where it is located. This can be as little as 2mm if in the CVA, and up to 30mm if outside the CVA, with a Crater being the most restricted in terms of size. But an autoglass technician will also need to assess the depth of any crack or chip before deciding whether a repair is possible. Windscreens consist of two layers of glass bonded together by a layer of laminate. If the crack or chip has penetrated the first layer of glass all the way to the laminate a repair will probably not be possible, especially if delamination is already visible.
Evidence of Past Repairs
Windscreens cannot be repaired indefinitely, and one of the first things a technician will look for is signs of past repairs to the windscreen. If there are signs of eight or more repairs anywhere on the windscreen, replacement will be necessary. But even if the windscreen has been repaired less than eight times, replacement could still be necessary. There cannot be more than two repairs within the CVA, but the technician will also use an overlay template – centred on the new damage – to evaluate the impact of other past repairs. If any past repairs fall partially or fully within the overlay area, further repairs will also not be possible.
The above criteria highlight why even though you could attempt to repair a windscreen chip or crack yourself, you should always have it done professionally to avoid putting yourself and other road users at risk. And a professional autoglass replacement and repair service provider should always explain why a repair is not possible, and you shouldn’t be reluctant to ask if they don’t offer up an explanation.