Log in or register
My AA Account

Sign in to see your cover and request assistance online

Log in

Don’t have a My AA account?

You’ll need your policy or membership number

Create an account

Your Finances

Loans | Savings | Credit Cards

Your Driving Lessons

Book a lesson

Windscreen safety and repair

A clear view of the road

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 essential for good vision but a bonded windscreen is also an integral part of the vehicle body shell and contributes towards overall strength and stiffness.

It's important to use a reputable supplier for windscreen replacement but it's not always necessary to get the screen replaced as some damage can be safely repaired at little or no cost.


You can improve vision a lot, particularly when the sun is low in the sky, by making sure that the windscreen is clean on the inside and outside.

Even if you're not a smoker a hazy film will build up on the inside of the glass over time. Scratches, abrasions and chips on the outside can make dazzle from the sun worse too.

Wiper blades may last up to two years at the most but it's good practice to renew them once a year. New blades clear the screen more effectively and help reduce the dazzling effect of the sun.

Keep the screen-wash topped up using a good quality screen-wash additive to help clean the screen all year round as well as reduce freezing in cold weather. 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 or even impair vision.

Damage of up to 40mm across can sometimes be repaired, depending on where in the screen it is situated. If the damage is right in front of the driver – the 'A zone' – only damage up to 10mm can be repaired. This is slightly less than the size of a 5 pence coin.

Repair involves cleaning and drying the damaged area and filling it with a clear resin with similar optical properties to glass.

The damage won't completely disappear but the repaired area will be much less visible and will have a smooth surface so wipers aren't damaged.

If ignored, small chips can grow and become irreparable. Secondary cracks can 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 so it's important to act quickly.

The MOT test

Depending on where it is located, some windscreen damage will result in an MOT failure if not attended to. The screen is divided into two areas for the purposes of the MOT.

Windscreen zonea 440

  • 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 doesn't clear the windscreen effectively to give you an adequate view of the road (through the windscreen) to the left and right sides of the vehicle, as well as to the front.

Wipers that judder, make a noise, leave bands of rain or unwashed margins should be replaced.

(Page updated 23 October 2012)