Damp Test

Motorhome and Caravan owners alike baulk at buying a used vehicle due to the concerns for damp.

damp test meter

Damp in a motorhome seriously reduces the value of the vehicle and if detected needs to be investigated and rectified without delay. Damp testing can be carried out using inexpensive equipment but for a thorough damp test more accurate (and inherently more expensive equipment is desirable) to prevent false alerts.


If you check Damp readings on an industry standard Protimeter type damp tester it has gradients coloured to the percentage of damp detected, these can also be seen in the table below:-

Reading Value Action
0 – 15% No Cause for concern
15-20% Require further investigation Consideration should be given to re-checking    the area in three months with the average of all readings taken.
20-30% Remedial work required, there may be early signs of water ingress or evidence of moisture. Resealing and internal work may be required; again, consideration should be given to re-checking the area in three months.
>30% Structural damage is occurring, deterioration inevitable. a full strip down of the affected area is required.


Self Check for Damp

  •     Look for Signs of Staining on the Interior wall boards
  •     Inspect internal Screws inside your motorhome or caravan for rust signs.
  •     Run your Finger along the Interior wall boards for Signs of Softness or Pitting (small bumps).
  •     Check any External rails and mouldings for dents or Gaps.

NOTE: During damp weather higher readings might be obtained, if so a revisit is recommended

motorhome damp testing

Where should I test for Damp with a damp tester ?

Peel up the window rubber and test behind

Test inside bed lockers / Under seats

Test inside cupboards

Damp does not always follow a pattern and may not show in the centre of a panel.

Check around standard ingress points such as windows or doors , along any points where seams run / roof meets ceiling / floor.

Check around any none standard factory fitted accessories such as cycle racks, awnings, satellite systems etc…..

Note: All wood contains moisture and according to the time of year and amount or type of use the moisture content will vary

We use a Protimeter BLD2000 Mini Damp Tester which has a dual prong head as standard but also comes with a very useful extension lead with prongs which is ideal for getting into spaces where the tester itself cannot fit. It has other facilities such as the ability to store the result of the test in cases where the angle to the indicator means you cannot read it in situ. See the demo video of it in action below:

[youtube id=”9rxyr4XWTKA”]

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