How Can the Weather Affect Chipped Windscreens?

Stone chip on windscreen

However minor it may be, a chipped windscreen is never something you should ignore. A chip can hinder your view out the front, and you could fail your MOT if it’s in the driver’s eye line. Not only that, but chips can spread very quickly into full cracks, and that means more expense and more hassle to get the damaged windscreen repaired.

While it is legal to drive with a minor chip in your windscreen, you need to be aware of the safety risks and what effect different driving conditions could have on the damaged area. Extreme weather like snow, ice and intense sunlight can all affect a chipped windscreen, and could quickly cause it to develop into a full window break.

In this guide, we look at the effects weather extremes can have on a chipped windscreen, and share some tips on what to do to stop the chip spreading before you can have the screen professionally repaired.

Does Cold Weather Affect Chipped Windscreens?

Man defrosts frozen windscreen on cold icy morning

A chipped windscreen is at its most fragile in cold weather, when freezing temperatures cause the glass to contract and become more brittle. When the windscreen freezes overnight, frost will get into the chip and could cause it to spread – especially if it’s a ‘star’ break with small cracks leading away from the impact mark.

Chips can spread rapidly in cold weather, especially if they’re freezing and then thawing out every day. This is due to the moisture inside the chip freezing – something that’s almost impossible to avoid in wintry conditions if you have nowhere warm and frost-free to store your car overnight.

Another thing to watch out for in the winter months is snow-build-up on the windscreen. An inch or more of the white stuff weighs more than you might think, and this weight can cause small chips to spread and crack, helped along by the fact that the windscreen will be frozen.

Here are a few tips on reducing the impact cold weather has on a windscreen chip:

  • Where possible, park your car in a garage overnight to prevent the windscreen from freezing.
  • If you don’t have a garage, invest in a good quality windscreen cover that’s tailored for your car. If it’s the right fit, it should stop the windscreen freezing. Keep in mind though that it won’t stop other parts of the car freezing, so you’ll still need to de-ice your other windows.
  • Use de-icer on the windscreen to remove ice, rather than relying on a scraper. This is by far the safest way to de-ice a chipped windscreen, with no sudden temperature change or anything to agitate the chip. And never use warm water to try to melt away a covering of ice.
  • Be wary of potholes or uneven road surfaces which might be full of water or covered in snow, masking how deep they are. Sudden jolts like these are exactly the kind of thing that can turn a small chip into a nasty crack.
  • When you’re parking your car during the day, try to find a spot out of the shade. Even a little weak winter sun will be enough to prevent the windscreen from re-freezing, so avoid shady spots where temperatures struggle to climb above freezing.

Does Warm Weather Affect Chipped Windscreens?

Sunlight reflectors on the windscreen to protect the car's plastic

Although wintry conditions are the worst for a chipped windscreen, very warm weather can cause problems too.

Just like cold weather causes the glass to contract, warm weather causes it to expand, and this added pressure can make the glass more brittle. This effect is at its worse in intense direct sunlight, so you should always seek out the shade when parking up during the summer months.

Similarly, warm weather causes the air inside the cabin to expand, meaning added pressure on the windows. As the air temperature inside the car increases, the air will press against the glass and put pressure on the chip, especially if the air cavity within the windscreen has been damaged.

One of the big things to remember about driving with a chipped windscreen in summer is the danger of sun dazzle. Sunlight catching the edge of a chip can send light bouncing around the inside of your car, which can be very dangerous while driving. Get a chip repaired without delay in the summer to avoid the effects of uncontrolled sun dazzle.

Here are a few tips on reducing the impact of warm weather on a windscreen chip.

  • Just like when it’s cold, parking your car in a garage when not in use will keep it cool, reducing the stress warm air places on the glass.
  • Park in the shade whenever you can to keep the car out of harmful direct sunlight. This is good practice for keeping the paintwork in tip-top condition, too.
  • Whenever it’s safe to do so, keep a window slightly open in your car, especially if it’s parked in direct sunlight. This will allow the warm air in the cabin to escape, so there’s less pressure on the windscreen.
  • Use a sun reflector to keep as much heat out of the cabin as you can. These fit over the windscreen inside the car, and prevent the interior getting too hot.
  • Dry conditions mean there’s a higher risk of stone chips and flying debris in the summer months, so be careful when driving on untreated surfaces or poorly-maintained roads. When a windscreen is already chipped, there’s a higher risk of it chipping or cracking again because its strength has been compromised.

Temporary Measures to Stop a Windscreen Chip Spread

Man carrying out repairs to a car windscreen

While we would always recommend having your chipped windscreen professionally repaired, there are a couple of things you can try to prevent the chip getting worse. We’ve listed these DIY windscreen repair options below:

  • Get a windscreen chip repair kit – Windscreen chip repair kits are designed to stop small chips and cracks from spreading, but don’t offer a professional repair or long-term fix. Kits like these include a special resin that re-laminates the glass to prevent it from spreading, but results can be mixed, and you’re not guaranteed a complete repair.
  • Get a professional repair – The best way to prevent a windscreen chip from spreading is to get it repaired straight away. While you could drive for a year without a chip spreading, there’s a risk it could crack within a day or two, and then you have a much bigger and costlier repair on your hands. If you don’t want to risk it, call in the pros straight away and they’ll soon have your windscreen back up to full strength. There are companies that will drive out to you to fix it, so it can be quite easy to arrange a proper repair.

At Prestone, our car maintenance products are tested in extreme weather, giving you complete confidence that they can deal with whatever comes your way. For more information, visit our homepage today.