Salt damage on your car – how to protect paint and underbody
Road salt keeps the roads safe, but it's an enemy of the car. It's corrosive, creeps in everywhere and works in hiding all winter long. Here's what salt actually does to a car – and how to both prevent and remove salt damage.
- Salt eats at paint, underbody, wheels and brakes – and speeds up rust
- The worst happens out of sight: wheel arches, door sills and the underbody
- Wash the car every 1–2 weeks in winter, the underside included
- Protected paint and frequent washing are the best defence against salt damage
What road salt does to a car
Salt lowers water's freezing point, and it's exactly this damp salt solution that's harmful. It clings to every surface and keeps them wet long after the road has dried:
- The paint loses its gloss and gets a dull, grey haze of dried salt
- Underbody and wheel arches – salt + moisture + bare metal is the classic recipe for rust
- Wheels are attacked by salt together with hot brake dust
- Brakes and brake lines corrode faster when salt is left sitting
Where the salt collects
The visible surfaces aren't the problem – it's the places you don't see.
- The wheel arches
- Door sills and thresholds
- The underbody
- Behind bumpers and trim
- The bonnet and roof
- The sides at eye level
- Whatever you happen to see walking past
The salt collects where it's damp and hard to reach – exactly where rust begins.
How often should you wash in winter?
The rule of thumb is every 1–2 weeks when salting is active, plus an extra round whenever a mild spell arrives. Don't wait until the car "looks dirty" – the invisible salt solution corrodes regardless. Remember to rinse the underbody, not just the bodywork.
Wipe a finger along the lower edge of the doors and behind the wheel arches. Feel a dry, white film like chalk dust? That's dried salt – and a sign the car needs a wash now.
Protect your paint from salt
We clean and polish salt-damaged paint and protect it with ceramic coating. Fixed price, we come to where the car is.
Get a quoteHow to protect against salt damage
Prevention costs far less than repairing rust and dull paint after the fact.
- Protect the paint with a sealant or ceramic coating – salt clings less and rinses off more easily
- Wash regularly throughout the salt season, focusing on the hidden surfaces
- Dry door seals and sills so salt water isn't left standing
- Winter-prep in autumn before the salt arrives – see our winter prep guide
Salt clings easily
Dirt and salt solution soak straight into the paint. Washing takes longer and has to be done more often.
Salt lets go faster
Slick, protected paint sheds salt and grime more quickly. Shorter, gentler winter washes every time.
Does your car already have salt damage?
Dried salt and dull paint can usually be saved if you act on it:
- Thorough degrease and wash dissolves and removes the salt layer
- Clay bar pulls out salt and contamination stuck in the paint
- Polishing restores the gloss where salt has dulled the paint
- Fresh protection goes on last, so the car can take the rest of the season
If the underbody has already started to rust, have a workshop assess it – the sooner, the cheaper.
Prices
Don't let salt sit all winter hoping to wash it off "in spring". By then the corrosion has had months to work. Regular washing along the way is always cheaper than fixing the damage afterwards.