Windscreen Safety and Repair
Your car's windscreen is far more than just a piece of glass to keep the wind and rain out.
A clean, clear windscreen is vitally important for good vision of course but a bonded windscreen is also an integral part of the vehicle body shell, contributing towards its overall strength and stiffness and therefore towards crash protection too.
So using a reputable supplier for windscreen replacement is as important as it is for crash repairs.
But it's not always necessary to get the screen replaced some damage can be safely repaired at little or no cost.
General Advice
You can improve vision significantly, particularly at times of the year when the sun is low in the sky, by making sure that the windscreen is clean – inside and out. Even if you're not a smoker the inside surface of the windscreen will inevitably accumulate a hazy film over time. Scratches, abrasions and chips on the outside can intensify the sun's dazzle too.
Wiper blades will last for two years at the most though it's generally recommended that they're renewed annually. New blades clear the screen more effectively and reduce the dazzling effect of the sun as a result.
It helps to keep the screen-wash topped up too – a good quality screen-wash additive will help reduce the risk of freezing in frosty weather and help clean the screen more effectively all year around – check the handbook carefully to make sure that you fill the right reservoir though.
Stone chips and cracks
Depending on size and position a chip on your windscreen can be a distraction and in some situations can impair vision too.
A chip doesn't always mean replacing the whole windscreen though – damage of up to 40mm can be repaired, depending on where in the screen it is situated. If the damage is right in front of the driver in the area known as the "A zone" (see diagram below) only damage up to 10mm can be repaired. This is slightly less than the size of a 5 pence coin.
Repair basically involves cleaning and drying the damaged area and filling it with a clear resin with almost identical optical properties to glass. The damage won't completely disappear but the repaired area will be smooth and structurally sound – reducing the risk of damage to the wipers – and much less visible.
If left unattended, small chips can grow and become un-repairable as secondary cracks form under the combined effect of heat, moisture, frost, dirt and vibration. Any dirt or moisture entering the chip will make it more difficult to produce a visually acceptable repair.
Stone chips and the MOT
Some windscreen damage can result in an MOT failure – another good reason to get damage repaired promptly.
For the purposes of the MOT test the windscreen is divided into two different zones
- Immediately In front of the driver (The "A-zone" – a 290mm wide band centered on the steering column and bounded top and bottom by the wiper swept area) – damage larger than 10mm across will normally result in a failure.
- Elsewhere on the windscreen – damage larger than 40mm across will normally result in failure.
Windscreen Wipers
Your car can fail the MOT if a wiper blade is insecure, missing, or in such a condition that it does not clear the windscreen effectively to give the driver an adequate view of the road (through the windscreen) to the left and right sides of the vehicle, as well as to the front.
If your wipers show any of the following signs of wear, they should be replaced
- Leaving bands of rain
- Leaving unwashed margins
- Juddering
- Making a noise
Visit Autoglass® to find out more about AA recommended windscreen repair or replacement.
Autoglass® offers AA members a free wiper check and 20% discount off a pair of wipers for which fitting is free (Free fitting is available in Autoglass® branches and in conjunction with mobile glass repairs and replacements only)
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11 April 2008