Winter car care in the UK: how to deal with road salt
By Ollie B - SoapX Ltd.
From October to March, UK roads are gritted with rock salt. The salty spray that ends up on your car holds moisture against metal, speeds up rust and dulls paint, wheels and glass. This is how to stay on top of it.
How to wash road salt off your car in 5 steps
- Rinse the whole car, especially the wheel arches, sills and lower doors where salt collects.
- Apply a winter pre wash from the bottom up and leave it for 2 to 5 minutes without letting it dry.
- Cover the car in winter snow foam, let it dwell for 3 to 5 minutes, then rinse from the top down.
- Contact wash with a shampoo that helps neutralise road salt, using two buckets.
- Rinse the arches and underside again, dry the car, and top up the sealant every few washes.
Do this every week or two while the roads are being gritted. Every SoapX product with a Winter (W) formula is in our winter car care range.
Why road salt is hard on cars
Rock salt works by lowering the temperature at which water freezes, and it relies on tyres to spread it across the road. Those same tyres throw it into your wheel arches, sills and underbody as a fine, wet film.
- Rust. Salt water conducts electricity far better than rain water, so bare steel corrodes faster. Stone chips, arch lips, brake parts and underbody seams suffer first.
- Wheels. Salt mixed with brake dust sits on alloys and can stain or pit the lacquer if it is left for weeks.
- Paint and glass. Dried salt leaves a white film that dulls the finish and causes glare on the windscreen at night.
Councils grit well under half of their roads on average, mostly the main routes. A motorway commute picks up far more salt than a week of short local trips, so wash to suit the miles you do.
Protect the car before the first frost
A layer of protection makes every winter wash easier, because dirt and salt release more readily. No.08 Wax and Sealant in the Winter formula gives a tougher barrier for salt season. Apply it to clean, dry paint and top it up every few washes.
- Touch in stone chips before winter, so salt water cannot reach bare metal.
- Give the wheels a thorough clean while the weather is still mild. Our alloy wheel guide covers the routine.
- Clean the glass inside and out, so it mists up less.
Wash little and often
In winter, a quick wash every week or two beats a long wash once a month. The less time salt sits on the car, the better.
- Rinse the whole car, paying attention to wheel arches, sills and the lower doors where salt collects.
- Apply No.01 Pre Rinse in the Winter formula, which has extra chelating power to lift road salt and winter grime. Work from the bottom up and leave it for 2 to 5 minutes without letting it dry.
- Follow with No.02 Snow Foam Winter, leave it to dwell for 3 to 5 minutes, then rinse from the top down. Our snow foam guide covers the settings, and the winter snow foam page covers the mix and the cost per wash.
- Contact wash with No.05 Contact Shampoo Winter, which helps neutralise road salt, using the two bucket method.
- Rinse the arches and underside again at the end.
Is today a good day for it? The car wash weather checker looks at the temperature, wind and rain where you are.
Clean the parts you cannot see
Most winter rust starts where you never look. Spend a few minutes of every wash on the hidden areas.
- Wheel arches. Flush each arch until the water runs clear. A long handle wheel arch brush shifts the packed grime on plastic liners. Keep it for arches only and never use it on paint.
- Underside. Run a hose along the sills and under the front and rear of the car. The jet setting on the hose quick connect set reaches further under.
- Door shuts and boot gutters. Salt water collects in the seams. Wipe them out and dry them.
Keep glass clear
Salt film on the windscreen causes glare at night. No.09 Glass and Visor Cleaner Winter adds anti fog and helps clear light frost. Use it inside and out with a waffle weave glass cloth.
Cold weather tips
- Avoid washing below freezing, as water can freeze in door seals and locks.
- Wash in the middle of the day when the panels are warmest, and dry the car straight away.
- Dry door shuts and seals after washing.
- Wash your textiles separately at up to 60°C to get salt out of the fibres.
Quick answers
How often should I wash my car in winter?
Every week or two while the roads are being gritted, and sooner after a long motorway run on salted roads.
Does rain wash road salt off?
Only partly. Rain thins the film on the upper panels, but it does not clear the arches, sills or underbody, which is where salt does the damage.
Does salt still work in very cold weather?
Rock salt works down to around minus 8 to minus 10°C. Below that, treated roads can still freeze, so expect more grit to be laid during a cold snap.
When can I stop the winter routine?
Gritting usually runs from October to March, but roads are treated whenever frost is forecast. When the last frosts have passed, give the car one thorough wash, including the arches and underside, and top up the sealant.
Not sure which winter products you need? The car wash product finder has a winter salt option and builds the kit list for you.
Kit for this job
- No.01 Pre Rinse and Bug Remover
- No.02 Snow Foam
- No.05 Contact Shampoo
- No.08 Wax and Sealant
- Long Handle Wheel Arch Brush
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