How to de-ice your car windscreen properly

Some people might reach for the kettle or their bank card to de-ice their car. But these methods could lead to a cracked windscreen or even a fine. 

Don’t worry. Some simple cupboard staples could keep your windscreen frost-free. And you won’t have to use that half-frozen bank card to pay off a fine.

Why does my windscreen ice up?

As the temperature drops below freezing, water vapour in the air becomes super-cooled. This causes frost and ice.

But the temperature doesn’t have to drop below freezing for your windscreen and windows to freeze over

The glass of your car's windows freeze over much quicker than any other surface of the car.

This is similar to how water vapour becomes condensation when it hits a cold surface.

Read our driving in winter guide for more tips on how to stay safe if you have to drive in icy conditions.

Step-by-step de-icing checklist

• Check your windscreen wipers. Make sure your wipers aren't switched on - if they're frozen to the windscreen they could be damaged when the engine starts.
• Switch on your ignition and crank the heat up.Turn your blowers to full and the temperature to high. Point them at the windscreen - if you have a heated windscreen option, switch it on. Switch on the A/C if you have it to keep the air dry. 
• Use a de-icer and ice scraper. It's always handy to keep a can of de-icer for the car nearby. If you've run out, you can make your own DIY de-icer at home. Next go to town on the ice using your scraper. You might need to scrape some ice off the inside of the windscreen, but this can be trickier due to the curved glass.
• Get rid of any condensation. All that hot air blowing at a cold windscreen might lead to condensation on the inside of the car. We've got you covered there too - here's how you get rid of condensation in the car

De-icing techniques to avoid

Don't use boiling water, it could be disastrous. The shock of the extreme heat on the cold glass could crack your windscreen. And fixing that isn't going to be cheap.

If you switch your engine on to warm your car up, don't wander back into the house for too long. Having an idle engine could land you with a £20 fine.

And if you're on your own, common sense says to not leave your car unattended while it's running.

When you're rushing to get away in the morning, it’s easy to reach for the nearest sharp object and carve a porthole in the ice.

But using anything other than a car ice scraper could scratch your windscreen.

But more serious is the possibility of a £60 fine and three points on your licence. This is the penalty for driving with a limited view of the road.

And with points on your licence, you might find that your car insurance costs go up when it comes to renew your policy.

So it’s best to stay on the right side of the law and get that windscreen completely clear before setting off.

Is de-icer spray bad for your car?

Car de-icer sprays are safe to use on your car. While you should take care to ensure it only goes on glass, it shouldn't damage your car’s paintwork.

That said, the combination of chemicals in modern car de-icer sprays tend to be bad for the environment. But it’s easy to make your own.

How to make your own homemade de-icer

Being able to make de-icer at home is a handy solution if you've ran out. It can also be a good alternative If you're concerned about the environment.

You can buy eco-friendly de-icers, but if you want to be even greener, a homemade de-icer might be the best option.

Make a solution using water and a teaspoon of salt. You can then use a misting spray bottle to spray it on the windscreen, or wipe it on with an old towel.

Don't overuse it, though. Salt could damage the windscreen, as well as collect around the washer fluid nozzles. Avoid spraying the paintwork too, as salt might corrode the metal.

One part water to three parts vinegar should work too if you don't want to use salt. You can spray this mixture on the windscreen the night before as a preventative measure too.

A mixture of two parts alcohol or surgical spirit to one part water is also effective.

You can also soak a towel in the salt-water solution and place it on your windscreen and windows overnight. This acts as a preventative measure and should keep your windscreen frost-free.

Because these solutions have low freezing points, they should make short work of the frost. This makes them perfect for de-icing.

How to keep car windows from freezing overnight

If you don’t have time to de-ice your car in the mornings or hate all the scraping, it may make sense to invest in a windscreen frost cover.

Alternatively, if you dread the thought of a frozen car you could consider a full car cover to protect all the windows and the bodywork too.

For more tips, check out our guide on winter motor maintenance.

Ice inside my windscreen - what can I do?

Getting rid of ice inside your windscreen is similar to de-icing and getting rid of condensation:

• Turn on your car’s heating system - it might be worth putting a towel underneath any frosty sections to catch any moisture.
• Use a heated, but not wet, towel and gradually rub away at the ice. You could use a hand warmer or heat pack for this too.

   

Ice inside your windscreen is often caused by moisture inside your car. If the temperature gets below freezing, this moisture can freeze causing ice inside your windscreen.

You can stop this happening in the same way as you would if you wanted to stop condensation inside your car:

• Get a dehumidifier for your car - this can remove any excess moisture
• Remove anything that could bring moisture into your car - for example, clothes or wet boots
• Clean your windscreen and windows, inside and out - moisture can settle on dirt so removing this could help stop moisture building up

If you’re taking these measures and still noticing moisture and ice inside your windscreen, it’s worth speaking to a mechanic. You might have a leak in your car that needs fixing.