How Often Should I Have a Damp Check Done?

If you own a motorhome, one of the most important (yet often overlooked) aspects of maintenance is checking for damp and water ingress. Left unchecked, damp can quietly cause structural damage, reduce resale value and compromise your comfort and safety. So the question is: how often should you have a damp check done?

Let’s dive into everything you need to know.

Why Damp Checks Matter

Water ingress is widely regarded as one of the worst issues for a motorhome’s habitation area. According to industry guidance:

• Many modern motorhomes use wood‑free or bonded construction but even these can still suffer leaks if sealants or joints deteriorate.
  
• Hidden water ingress behind panels or in floor areas can escalate into extensive repairs.
  
• Most manufacturers want you to have a yearly habitation and damp check to keep your warranty valid. Elddis, for example, says your motorhome should have an annual service and damp inspection done by an approved centre.

In short: damp checks aren’t just optional. They’re vital for preservation, safety, and warranty compliance.

Recommended Frequency of Damp Checks

At least once a year

For the majority of motorhome owners, a minimum of one damp check every 12 months is the standard recommendation. This is often done as part of the annual habitation service.

• The service check sheet for UK motorhomes notes: Damp test – carry out & note readings on a separate damp report sheet.
  
• Moisture readings of up to around 15% are usually nothing to worry about, but anything over 20% is a sign that further investigation is needed.

More frequent checks for higher‑risk vehicles

If your motorhome is stored outdoors year-round, used heavily, or has a previous history of water ingress or leaks, it’s wise to carry out damp and seal checks more frequently—ideally every 6 to 9 months. Key times include before and after the main travel season, as well as after prolonged periods of heavy rain or freezing weather.

Outdoor storage exposes your vehicle to ongoing environmental stress, including UV damage, rain, frost, and temperature fluctuations, all of which can accelerate the wear of seals, joints, and roof coatings. These conditions also increase the risk of condensation build-up, especially if ventilation is poor or the vehicle remains closed for long periods.

Regular inspections allow you to catch small issues early, such as perishing seals, loose fittings, or early signs of damp—preventing costly repairs and helping to preserve your motorhome’s long-term value.

What a Damp Check Involves

When you book in a damp check (often as part of a habitation service) you should expect:

• A moisture meter scan of walls, floors, ceilings and key junctions. For example: 0‑15% reading = “no cause for concern”; 15‑20% = monitor; above 20% = further investigation.
  
• A full damp report with readings, diagrams and recommendations.
• Inspection of seals, roof lights, windows, locker doors, body joints and floor/ceiling for signs of ingress or delamination.
  
• Checking of ventilation, condensation risk and interior humidity/airflow.

Signs to Watch Between Checks

Between your professional inspections, stay alert for early warning signs. These include:

• Musty or mouldy smell as you step in.
• Black mould spots around windows, door seals or vents.
  
• Soft or spongy wall or floor panels, or a creaky floor.
  
• Persistent condensation on windows/cupboards or unexplained water pooling.
  
• Visible cracks, damaged sealant, or modifications (e.g., bike rack fixings) that may allow water in.

If you spot any of these signs, you should not wait for the next annual check– book a damp inspection sooner.

Benefits of Regular Damp Checks

Ensuring you have the damp check done routinely offers several important advantages:

• Early detection means smaller repairs rather than major restoration.
  
• Preservation of value -a documented history of checks is attractive if you ever sell.
  
• Warranty compliance– missing the annual check may invalidate some manufacturer guarantees.
  
• Peace of mind– your motorhome remains safe, dry and ready for travel.
  
• Cost‑effectiveness– preventing major water damage is far cheaper than repairing it.
  

Extra Considerations & Best Practice Tips

• Choose an approved workshop: In the UK, many workshops carry the National Caravan Council (NCC) Approved Workshop Scheme (AWS) accreditation. Using such a workshop ensures standardized checks.
  
• Retain your report: Keep the damp report and service checklist safely- useful for warranty claims or resale.
  
• Store well: If your motorhome spends long periods in storage, make sure it’s ventilated, protected from frost and condensation, roof lights are sealed, and seals are lubricated.
  
• Schedule around seasons: A damp check after winter storage and again pre‑season can catch problems early.
  
• Know your readings: Understand the thresholds- e.g., major concern above 20–25% moisture.

Conclusion

Regular damp checks are something you should treat as essential maintenance- not optional. For most owners, one check per year, ideally as part of your habitation service, is the baseline but if you store outdoors, experience heavy use or have had past issues- you may need more frequent attention.

Treating damp as an early‑warning issue, rather than waiting for visible signs, can save you time, money and hassle and ensure your motorhome remains safe, dry, and holiday‑ready!

Ready to book your check?

At Bristol Caravans & Motorhomes we include a full damp inspection as part of our habitation service- you’ll receive a detailed report with moisture readings and recommendations.
📞 Call us: 01454 612 893
📄 Need more info on damp prevention? See our guide: How to avoid damp in your caravan or motorhome