If there is one number one enemy of the motorhome, it's damp. A leak that isn't caught in time can rot the internal structure (which in many campers is timber), ruin the insulation and lead to a very expensive repair, as well as destroying the resale value. The good news: spotting it early and preventing it is in your hands. Here's how.
Why damp is so serious
The structure of many motorhomes (walls, roof, floor) contains timber or materials that rot and swell if they get wet repeatedly. The problem is that the damage advances inside, out of sight, and by the time it shows on the surface it is usually well established. That's why early detection is everything.
How to spot a leak in time
- Check the sealant regularly: the seals around roof lights, windows, aerials, trims and roof joints. If the sealant is cracked, lifting or dried out, that's the way in.
- Look for signs inside: stains, bulging, a soft feel to walls or ceiling, a musty smell, mould.
- Use a moisture meter: a simple device that measures the moisture in the timber; many workshops run one over the vehicle at a service (and it's what a buyer checks on a second-hand one).
- After heavy rain, check inside in case anything new has appeared.
How to prevent it
- Keep the sealant up to date: check it at least once a year and reseal as soon as you see it deteriorating (with products made for motorhomes).
- Ventilate: a lot of interior damp comes from condensation; ventilate daily and when cooking or showering (see condensation).
- Look after the roof: it's the most exposed area; inspect it carefully and don't walk on it unless it's designed to be walked on.
- Periodic professional inspection: many manufacturers make their water-ingress warranty conditional on annual workshop inspections. [Note: check the water-ingress warranty terms with your own manufacturer.]
In short
Damp is the camper's worst enemy because it rots the structure from the inside without showing; the defence is catching it early and keeping the sealant up to date. The step you can take today: check the sealant on the roof, roof lights and windows, and if you have the slightest doubt, run a moisture meter over it or take it to a workshop; preventing a leak costs far less than repairing a rotten structure. Combine it with the maintenance checklist.