Using a damp meter

[Mandarin]

I've just bought a. brennenstuhl damp meter as the last service found 19% in one spot of the floor, maybe not surprising as it was serviced after 7 months shut up with no heating., but I want to keep an eye on it, we did find and fix a potential source, a small split in the wheel arch at floor level.

The van is a Bailey Alutech construction with the floor covered wall to wall in vinyl. To read the moisture in the floor do I have to pierce the vinyl, and am I correct in thinking there's no risk of damp in the walls or ceiling?

If so when buying a 2nd hand van do people really expect buyers to pierce the floor, or is the only option to buy the much more expensive meter without the prongs?

 

[Jcloughie]

You have realised the Achilles heel of damp testing. Are you doing it for show, are you testing the vinyl or the structure, are you causing damage. The answer might be a non invasive tester.

Fot the second year running my AWS engineer has not used any tester, following the latest advice from the organisation which differs between caravan makes. He does have a non invasive tester which he told me costs him £500+. I think he used it just to double check.

Seems the current advice for Lunars at least, is observation and feel.

John

 

[Buckman]

Protimeter is the non evasive one and can cost from £400 upwards.

 

[Raywood]

Lunar and Eldiss which still have wooden frames and older models of other makes with these are the ones that need testing as they are the most susceptible to damp.
Frankly feeling will not spot a problem in many cases until it is too late and the wood has rotted.

 

[Jcloughie]

Lunar and Eldiss which still have wooden frames and older models of other makes with these are the ones that need testing as they are the most susceptible to damp.
Frankly feeling will not spot a problem in many cases until it is too late and the wood has rotted.

Not according to AWS, Perhaps you have more up to date information. All vans are susceptible to ingress, but some rot, others just get wet.

There are many examples of vans with damp passing the test. And, In my case, the reverse. Prior to AWS deciding NOT to test, an engineer highlighted a high reading in the floor of my van. That location has been monitored for the last 3 years and is fine.

John

 

[Buckman]

I have never heard that AWS technicians no longer do a damp test, but on checking I came across this; In light of the newer construction methods, the requirement for damp testing in some areas of some of the makes/models is no longer required. Please refer to your workshop for more information on the specific manufacturer requirements of your particular unit.
Obviously only refers to some caravans and the use of a damp meter with probles.

 

[Mandarin]

Thanks for the comments, so looks like the prong type damp meter is not much use to us caravanners. Which is interesting given how many posts you see on forums saying 'get a damp meter', for DIY use the protimeter type is out of the question.

I'm particularly interested as we're going to change vans next autumn and so of course want to check any we go and see, but I'm certainly not happy to do this by feel.

Before damp meters were available I used to check wooden boats with a hammer, sound wood had a sharp note, rotten a dull note, but I guess that would not work through vinyl.

 

[Jcloughie]

Thanks for the comments, so looks like the prong type damp meter is not much use to us caravanners. Which is interesting given how many posts you see on forums saying 'get a damp meter', for DIY use the protimeter type is out of the question.

I'm particularly interested as we're going to change vans next autumn and so of course want to check any we go and see, but I'm certainly not happy to do this by feel.

Before damp meters were available I used to check wooden boats with a hammer, sound wood had a sharp note, rotten a dull note, but I guess that would not work through vinyl.

My advice was based on two things, what my engineer passed on to me as the current thinking. And, my experience of prong type meters. I used to teach the use of damp meters in timber. In those circumstances they work fine but certain protocols have to be followed to avoid false negatives and false positives. Caravans are far more difficult because the surfaces are covered with impervious materials.

Customers like to see the percentage readings, perhaps engineers pander to this. But in my opinion, it’s a very inexact science. Others will differ.

I have no idea how accurate a non invasive meter might be in a caravan. But interesting that AWS don’t insist in the use of them and favour touch and see.



John

 

[Buckman]

My advice was based on two things, what my engineer passed on to me as the current thinking. And, my experience of prong type meters. I used to teach the use of damp meters in timber. In those circumstances they work fine but certain protocols have to be followed to avoid false negatives and false positives. Caravans are far more difficult because the surfaces are covered with impervious materials.

Customers like to see the percentage readings, perhaps engineers pander to this. But in my opinion, it’s a very inexact science. Others will differ.

I have no idea how accurate a non invasive meter might be in a caravan. But interesting that AWS don’t insist in the use of them and favour touch and see.



John

Dealerships still use meters for doing damp check so cannot understand why AWS have dropped the test for many brands. After all you still get damp around windows, doors and lockers on all brands. In addition this may invalidate any claim for warranty work regarding damp if the damp is missed by the AWS tech using the touch method.

 

[Jcloughie]

Dealerships still use meters for doing damp check so cannot understand why AWS have dropped the test for many brands. After all you still get damp around windows, doors and lockers on all brands. In addition this may invalidate any claim for warranty work regarding damp if the damp is missed by the AWS tech using the touch method.

As long as the damp check method used is that approved by AWS for that model, and it is done by an accredited engineer. Then it will conform to the warrantee requirements.

I would be interested to know the the detail of the latest advice, I have searched, but I guess it’s only visible to accredited AWS members.

John

 

[Hutch]

I am willing to have my Service technician test and certify my caravan, for damp. IF i were to buy a second hand caravan from a dealer I would want a damp report. , Would they say its a 2021 year and doesnt need it ???in maybe 2020

 

[Jcloughie]

I am willing to have my Service technician test and certify my caravan, for damp. IF i were to buy a second hand caravan from a dealer I would want a damp report. , Would they say its a 2021 year and doesnt need it ???in maybe 2020

You still get a report Hutch. It’s just the method used to assess has been updated. Mine was assessed as damp free, but no percentages given.

John