Damp in motorhomes and campervans, where it hides and how to check

Quick Answer:

• Water ingress is a significant concern for leisure vehicles, potentially affecting structural components if left unaddressed.
• Key hotspots include window seals, rooflights, and external locker frames where seals may degrade over time.
• A professional habitation check by an Approved Workshop Scheme (AWS) technician is the industry benchmark for motorhome and touring caravan servicing.
• The AWS is a joint enterprise between the NCC (National Caravan Council), The Caravan and Motorhome Club, and The Camping and Caravanning Club.

In the UK's climate, moisture management is a critical aspect of motorhome and campervan ownership. Undetected water ingress can lead to progressive issues that affect the longevity and resale value of your investment. Whether you are looking at a large coachbuilt motorhome or a compact van conversion, the principles of moisture detection remain the same. The good news is that many issues can be identified early through methodical inspection and professional servicing by qualified caravan and motorhome servicing professionals.

Common Hotspots: Where Moisture Enters

Water typically enters a vehicle through apertures or where the body shell has been pierced for accessories. When inspecting used motorhomes for sale, pay close attention to these specific areas:

• Windows and Seals: Inspect the rubber seals for signs of degradation or black spotting. Moisture trapped between double-glazing panes can also indicate a seal failure.
• Rooflights and Vents: These are high-stress points on the roof. Look for any staining or discolouration on the ceiling panels surrounding these frames.
• External Lockers and Seams: Any break in the outer skin represents a potential risk. Check the internal corners of garage spaces and gas lockers for signs of moisture.
• Rear Corners and Lower Panels: Road spray can impact the lower sections of the vehicle. It is important to check the integrity of the underseal and the lower floor panels.
• Awning Rails and Attachments: Rails or bike racks mounted to the exterior can provide a path for water if the sealants used during installation have failed.
• Solar Panel and Aerial Entry Points: Aftermarket additions require careful sealing. Cable entry glands should be checked to ensure they remain watertight and UV-resistant.

The Sensory Inspection Checklist

While professional tools are essential for a definitive assessment, your senses can provide early warning signs during a viewing. Use this checklist when exploring campervan makes:

1. Visual Inspection

Look for small grey or black spots on the interior wallboards, which may indicate mould growth. Check inside high-level lockers and under bed bases, specifically where the wall meets the floor. Use a high-lumen torch to inspect dark corners and areas behind furniture where air circulation might be restricted. Any bubbling or peeling of the interior vinyl or wallpaper should be noted for further investigation.

2. Physical Assessment

Run your hands over the interior wallboards. They should feel firm to the touch. Any areas that feel different from the surrounding panels may require a professional moisture test. Similarly, the floor should feel solid underfoot. If you notice any unusual movement or sounds when walking through the vehicle, it is advisable to have an AWS technician perform a full inspection.

3. Odour Detection

Be mindful of the interior scent. While many owners use air fresheners, a persistent damp or musty smell can be an indicator of moisture issues. Open all cupboards and lockers to check for concentrated odours in enclosed spaces.

The Importance of Professional Habitation Checks

The Approved Workshop Scheme (AWS) is currently the UK's largest group of independently assessed workshops. For peace of mind, owners are encouraged to use an Approved Workshop to service their touring caravan or motorhome. These workshops must pass an annual inspection by a team of independent assessors to ensure they comply with rigorous standards.

• Warranty Compliance: Many manufacturers recognise the AWS for servicing during the warranty period. It is essential to check the scheme supporters page to ensure your specific manufacturer recognises the scheme to maintain your warranty.
• Pre-Purchase Inspections: If you are considering a purchase from caravan dealers or private sellers, many Approved Workshops offer pre-owned pre-purchase inspections.
• Qualified Professionals: AWS workshops are run by fully qualified caravan and motorhome servicing professionals, ensuring that the right things are done by the right people.

Ask for Evidence, Not Reassurance

A transparent seller should provide a comprehensive history of the vehicle. Before committing to a purchase, request the following documentation:

• Habitation Inspection History: Look for annual reports from an AWS-approved technician. This provides a year-on-year record of the vehicle's condition.
• Service Records: Ensure the vehicle has been maintained according to manufacturer guidelines. You can learn more about this in our guide to habitation checks explained.
• Repair Invoices: If any remedial work has been carried out, ensure it was completed by a professional workshop and ask if any warranties on the work are transferable.
• Storage History: Inquire about how the vehicle was stored during the winter months, such as whether it was kept under a breathable cover or in a dry storage facility.

What to Do if Issues are Identified

Identifying potential moisture issues does not necessarily mean you should abandon a purchase, but it requires a change in strategy. It is important to understand the scale of the work required.

• Seek a Professional Quote: Repairs can vary significantly in cost. Re-sealing an external rail is a standard maintenance task, whereas addressing internal structural components is more labour-intensive.
• Consult an AWS Technician: Only a qualified professional can provide an accurate assessment of the remedial work needed to return the vehicle to a sound condition.
• Consider Other Options: If the extent of the issue is unclear or the seller cannot provide adequate documentation, there are many other used campervans for sale available through reputable sources.

Frequently Asked Questions

What is the Approved Workshop Scheme (AWS)?

The AWS is a joint enterprise between the NCC, The Caravan and Motorhome Club, and The Camping and Caravanning Club. It is the only scheme supported by all major UK manufacturers for motorhome and touring caravan servicing.

Does an MOT include a check for damp?

No. An MOT is a mandatory test focused on roadworthiness, such as brakes, lights, and tyres. A separate habitation check is required to assess the living area, including moisture levels and gas safety.

How often should I have my motorhome serviced?

It is generally recommended to have a professional habitation check performed annually. This ensures that any potential issues are identified early and helps maintain the validity of manufacturer warranties.

Can I use any workshop for warranty repairs?

Before booking a service or repair, you must ensure the manufacturer of your product recognises the workshop. Many manufacturers recognise the Approved Workshop Scheme for servicing during the warranty period.

Where can I find a reliable workshop?

You can use the AWS member directory to find over 550 fixed and mobile Approved Workshops across the UK. This ensures the work is carried out by qualified professionals to a high standard.

What should I do before buying a pre-owned motorhome?

It is highly recommended to arrange a pre-purchase inspection through an Approved Workshop. These professionals can identify hidden issues that may not be apparent during a casual viewing.

What to Do Next

• Browse campervans for sale to see the latest available stock from verified sellers.
• Check your potential vehicle's weight limits with our motorhome weight checker.
• Explore different campervan layouts to find a design that suits your travel needs.
• Find a local professional by visiting campervan dealers who participate in recognised industry schemes.
• Read our detailed breakdown of what happens during a service in habitation checks explained.