Acceptable moisture levels

[Phoenix1]

Can anyone tell me what an acceptable level of moisture in a caravan is please. I'm about to start the search for a second hand van andwill be armed with my damp meter.......

 

[Ogre]

The short answer is that NO damp is acceptable. Realistically, though, you'll probably be hard pushed to find a second hand van without any damp at all. My advice would be to check every single van that you like the look of, and then when you decide on 'the one' get the owner to agree to an independant damp inspection at the nearest caravan dealers. If he is hesitant about it, then walk away. There are lots of second hand vans, and you don't want to be buying a money pit.

A useful device for caravanners is the Desivent device which gives early warning of damp problems, and can be money very well spent. For under

 

[Damian]

Here are the industry reference points relating to moisture levels in caravans.

These measurements are ONLY for use with the Protimeter tester, not any of the cheap and cheerful, and very misleading, other makes.

Readings between 0-15% no cause for concern

Readings between 15-20% engineer to make note of readings and recheck at next service.

Readings between 20-24% possible early sign of water ingress, look for tangible evidence or ask for

Recheck.

Readings between 25-30% moisture evident, remedial work necessary, may not require stripdown unless surface damage (staining, pimpling and softness) is apparent. There is a risk of wallboard deterioration due to retained moisture in the structure if re sealed only.

Reading of 31% and above structural damage is occurring, deterioration inevitable, full stripdown of affected area is required

Whilst it seems very simple to get a reading and think you have a problem, it is not and other considerations have to be borne in mind when taking readings, such as ambient temperature, humidity etc.

Hope this helps

 

[ProfJohnL]

Hello Pheonix,

Damian's reply is pretty comprehensive, but I would re-emphasise that unless you know exactly what you are doing, it is very easy to get misleading readings from damp meters.

Sadly this Achilles heel of damp meters and the public's lack of knowledge, is used by some unscrupulous dealers to mislead customers about the extent of a problem.

By all means use it for a quick indication, but only a proper survey will reveal the truth.

 

[WilliamTups]

Damian,

What would be your view on a 12 month old caravan with readings of 80% damp and soft wallboards and roof?

Regards, Bill

 

[MickC1]

Hi Keith. Just looking at the Desivent. I'm not sure that it would actually work correctly. All that it does is check the moisture in the air, not in the actual caravan structure. So this won't prove anything. If it's a damp day then it's probably going to read in the red. Damp in the structure can only be tested with a professional damp meter as Damian describes. The caravan wall is basically waterproof on the inside and outside, so you need to get beneath the skin in order to test the structure.

Phoenix do be careful if using the probe type tester on someone else's caravan, e.g. on a dealer forecourt. If you don't do it properly and leave lots of holes in it then the dealer isn't going to be too impressed. I saw one recently where a customer had done their own test and it ruined the inside of the 'van. Pinholes everywhere.

William, a 12 month old caravan should still be under warranty, so get it fixed by a dealer if it has 80% damp, as you're talking major structure damage, (or an inaccurate reading of course).

At the moment there are lots of flood damage 'vans around, so beware.