If there’s one thing that can destroy a caravan, it’s damp. Water finds its way in through a tiny crack in the sealant, a failed window seal, or a leaking roof vent, and quietly rots the wooden frame from the inside out. By the time you notice it, the damage can be extensive and expensive.
Here’s how to catch damp early and what to do about it.
What Causes Damp in Caravans?
Most caravans are built with an aluminium or fibreglass skin over a wooden frame. The wood is the structural skeleton, and it’s vulnerable to moisture.
Common entry points for water:
- Roof seals that have cracked or shrunk over time
- Window seals that have perished
- Door seals that no longer sit flush
- Roof vents and hatches with deteriorated gaskets
- Corner joints where panels meet
- Antenna or solar panel mountings on the roof
- Underneath where the floor meets the chassis (splash-back from the road)
Water only needs a tiny gap to get in. Once inside the wall cavity, it has nowhere to go. It sits there, soaking into the wood, and rot begins.
How to Check for Damp
The Nose Test
Open the caravan door after it’s been closed for a while. A musty, mouldy smell is the first sign. Caravans should smell neutral or slightly woody, not damp.
The Press Test
Push firmly on the interior walls, especially:
- Around every window frame (top corners are most vulnerable)
- In the corners of the caravan
- Around the bathroom and kitchen areas
- Along the bottom edge of walls near the floor
- Around roof vents and hatches
Healthy walls feel solid and firm. If the wall flexes, feels spongy, or you can push your finger in, the wood behind is rotting.
Visual Signs
- Discolouration or staining on walls or ceiling
- Bubbling or rippling on interior panels
- Peeling wallpaper or trim
- Dark spots, especially in corners
- Mould growth (black, green, or white spots)
- Warped or swollen panels
- Rust stains running down from fixings
The Floor
Walk slowly through the caravan and pay attention to what you feel underfoot. Soft spots, bouncing, or a spongy feeling means the floor ply has started to deteriorate. Check carefully around the toilet, shower, and sink where water is used daily.
The Damp Meter
For a definitive answer, use a damp meter. These are handheld devices that measure moisture content in the walls. You can buy one for R200-R500, or ask a dealer or caravan repairer to do a professional damp check.
A reading under 15% is normal. Over 15% is damp. Over 25% means active water ingress that needs urgent attention.
How Serious Is Damp?
Early Stage (Localised)
If it’s caught early and limited to a small area around a specific seal failure, the repair is manageable. Reseal the entry point, dry out the affected area, and possibly replace a small section of internal panelling.
Cost: R500-R2,000 depending on the area.
Moderate (Spreading)
If the damp has spread along a wall section, the repair is more involved. You may need to remove interior panels, replace sections of the wooden frame, and rebuild the affected area.
Cost: R3,000-R10,000.
Severe (Structural)
If the rot has reached the structural frame, floor, or multiple walls, the caravan may need a major rebuild. In some cases, the cost of repair exceeds the value of the caravan.
Cost: R10,000-R30,000+ or write-off.
How to Prevent Damp
Reseal Regularly
Check and renew roof and window sealant every 1-2 years. Use a quality caravan sealant (not bathroom silicone). Pay special attention to:
- The roof-to-wall joint
- Around windows and doors
- Roof vents and hatches
- Any mounting points on the roof
A tube of sealant costs R100-R200. A damp repair costs thousands.
Store Properly
- Keep the caravan covered or under a roof if possible
- Don’t let it sit with blocked gutters or in a low-lying area where water pools
- If using a caravan cover, make sure it breathes to prevent condensation
- Open windows and vents periodically to air it out
Ventilate
Condensation from cooking, breathing, and showering inside the caravan can cause damp too. Use roof vents, open windows when possible, and consider a small dehumidifier if the caravan is stored closed for long periods.
Check After Every Trip
Before you lock up and leave, do a quick walk-around:
- Check the roof for any new cracks or damage
- Run your hand along window seals
- Look inside for any new water marks
- Leave a vent slightly open for airflow
Buying a Caravan? Always Check for Damp
If you’re buying a second hand caravan, a damp check is the single most important inspection you can do. Don’t skip it. Don’t take the seller’s word for it. Check it yourself or have it checked professionally.
A caravan that passes a damp check is a caravan you can buy with confidence. One that fails needs a price reduction that reflects the repair cost, or should be avoided entirely.
Caravan Damp Concerns?
At Caravan Center in Vereeniging, every caravan we sell has been checked for damp. We won’t sell a unit with hidden moisture problems. If you’re worried about a caravan you already own, bring it in and we’ll take a look.
Contact us at caravancenter.co.za/contact.
