How to Clean a Caravan or Motorhome Without Damaging It
The right caravan cleaner and the right technique matter more on a leisure vehicle than on any car, because the surfaces are softer and the stakes are higher — one cracked seal and you're into damp repairs. We make Caravan Pro™ caravan and motorhome cleaner at our factory in East Kilbride, and this is the method we'd use on our own vans: black streaks, green algae, GRP, decals, the lot.
Why do caravans get so dirty in the first place?
Three different soils build up on a leisure vehicle, and they need slightly different handling. Traffic film — diesel soot, brake dust and road oils bonded on during towing. Black streaks — rain-carried oxidation from rubber seals and aluminium fittings that runs down from awning rails, roof joints and window rubbers. And green algae, which colonises the shaded, north-facing side of anything parked up over a British winter. Ordinary car shampoo shifts none of these convincingly; that's a job for surfactant chemistry with proper dwell time.
What makes a caravan cleaner "safe"?
It has to be non-caustic. Caravan bodywork is GRP or fibreglass with acrylic (not glass) windows, printed decals, aluminium trim and a network of rubber seals and mastics keeping the weather out. Caustic traffic film removers — sodium hydroxide-based — dull gelcoat, craze acrylic and strip the plasticisers from rubber over repeated washes. Our caustic vs non-caustic TFR comparison covers the chemistry, but the short version is: check the safety data sheet, and if caustic soda is on it, keep it away from the van.
How do you clean a caravan step by step?
- Rinse first. Knock off loose grit with plain water so you're not dragging it across the gelcoat later.
- Dilute your cleaner. Caravan Pro goes 1:20 with water for a general wash — one 5L bottle makes 100 litres of solution, which works out around 25p a wash.
- Apply bottom to top, panel by panel, with a pump sprayer or through a pressure washer's chemical feed at 1–2% pickup. Working upwards stops concentrated runs streaking dry panels.
- Let it dwell for two minutes. This is where the surfactants release the bonded film — don't rinse early.
- Agitate the stubborn bits with a soft brush or wash mitt: lower skirts, wheel arches, around the awning rail.
- Rinse top to bottom with clean water, keeping the flow moving across seams and seals rather than blasting directly at them.
How do you remove black streaks?
Strengthen the mix, not your scrubbing arm. Mix at 1:5 for streaked areas, apply, give it two minutes, then a light pass with a soft brush and rinse. The streaks are oxidation bonded to the gelcoat, so they need chemistry and dwell rather than force — aggressive scrubbing on GRP just leaves swirl marks in the surface you were trying to save.
What about green algae on a static?
The hand-wash method suits statics where park rules or access rule out a pressure washer: 1:20 in a pump sprayer, section by section, dwell, agitate, rinse with a hose or watering can. The surfactant formula lifts winter algae in one pass on the north-facing side — the same green growth that laughs at shampoo.
Do you need to wax afterwards?
With most cleaners, yes — washing strips whatever protection was there. Caravan Pro sidesteps the extra step by depositing a light blend of carnauba and synthetic waxes as you rinse, protecting the body for up to six months. It's the difference between a wash that leaves the surface bare and one that leaves it beading.
Frequently asked questions
Can I use washing-up liquid on a caravan?
Best not. It contains salt, strips any wax protection and does nothing for black streaks or algae. It's also prone to leaving smears on acrylic windows.
Is a pressure washer safe on a caravan?
Yes, with sense: keep the lance moving, stay back from seals, vents and decal edges, and use a fan pattern rather than a pencil jet.
Will one product really do streaks, algae and road film?
Yes, if the concentration is adjustable. Caravan Pro handles general film at 1:20 and streaks or algae at 1:5 — same bottle, different mix.
Can I use it on the tow car too?
Yes. It's non-caustic TFR chemistry underneath, so the same 1:20 mix washes the car, van or 4x4 safely.
One bottle for streaks, algae and road film — Caravan Pro™, non-caustic, batch-tested in East Kilbride, with built-in wax. £24.99 for 5L (about 25p a wash).
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