How to remove damp from my Nuevo

My wife and I own a Nuevo EK 2 berth motorhome bought new in 2010. Last week we had the motorhome serviced and habitation checked. The habitation check found for the first time that there was evidence of some damp in the locker area Underneath the passenger bench seat. 

I have bought a Protimeter Mini Moisture Meter so that I can observe for myself the % readings.

I should be most grateful if members would kindly offer advice as to how I reduce the dampness which in some places is 30% especially on the vertical exterior panel near to the wheel arch which can be found in the locker area. The wall is dry 8cm above the flooring.

At the moment I have been using a fan heater which has helped to bring the percentage score down especially on the floor where the score was 20%. Now it is down to 14%. To solve the problem of damp on the vertical panel at 30% do I need to run the heating 24/7 and what time period are we thinking of? Should seven days be enough? Should I continue using the fan heater method or turn on the motorhome heater system to produce general background heat in the unit?

I think I know where the water is coming in albeit by capillary action. I anticipate using Sikaflex 512 to effect a repair. However, any advice on removing the old sealant, preparation and application of the sealant would be most welcome.

Hi,I keep a small oil filled heater on low and also a dehumidifier running and drained through a pipe into the waste tank which I also keep in the open position.
Hope this helps and you can get on top of the problem.
Regards Gary.

A dehumidifier is the best option. It will remove moisture from the air allowing more moisture to evaporate from your damp patch.  It will only treat the symptoms, not the cause !  Keith

KMRTOPAZ wrote:A dehumidifier is the best option. It will remove moisture from the air allowing more moisture to evaporate from your damp patch.  It will only treat the symptoms, not the cause !  Keith

By this method, won't you simply be drawing in more damp air from the outside through the copious mandatory ventilation surrounding windows, skylights and general gaps about the structure of the van, in other words trying to suck the planet dry? Regards.

Paramedic +1.

Simple test.

Run a dehumidifier for a fortnight. Empty the reservoir and run it again for a week. If it really is working in the way that many people imagine, there should be almost no water in the reservoir at the end of the second week.

The Hab area should now be completely dry after the first fortnight of operation.

I had a serious leak in my old Swift coachbuilt.  Much rotten wood had to be replaced.

I also used a dehumidifier for a couple of weeks but as Paramedic suggested, you will indeed be trying to dry the planet :)

I used clingfilm on every single roof vent, wall panel, airduct, etc that I could find, both inside and out!  Trying to make the van as air-tight as I could.

Agree with the above regarding dehumidifiers. Same with heaters, a waste of energy in my opinion. Ventilate the van with open windows and roof vents whenever the weather allows is the best option. Difficult in winter I know.
Al.

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I got a couple of these cheaply in Aldi a couple of year ago. They are excellent for drawing damp out in a small space such as a locker. You alternate them, one working while the other is drying.

Your damp sounds quite extensive. Is it possible to identify the area affected on a photo?

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Drag and drop the images onto the green box. Its a long time since I first did this so can't remember if you have to register with the host derver first time you do it?

Paramedic wrote:

KMRTOPAZ wrote:A dehumidifier is the best option. It will remove moisture from the air allowing more moisture to evaporate from your damp patch.  It will only treat the symptoms, not the cause !  Keith

By this method, won't you simply be drawing in more damp air from the outside through the copious mandatory ventilation surrounding windows, skylights and general gaps about the structure of the van, in other words trying to suck the planet dry? Regards.

Yes it will absorb moisture drawn in from outside the van, but it will also significantly lower the vapour pressure inside the van which will draw moisture from the affected area.  I cannot think of any other means of removing damp more effectively, and if, in order to achieve this, we absorb "atmospheric" moisture as well....so be it!   Keith

KMRTOPAZ wrote: it will also significantly lower the vapour pressure inside the van which will draw moisture from the affected area.

Hi Keith

  I don't understand this. Can you explain further please.

I'm confused now. 

For a dehumidifier to work in a confined area, the room, or van, has to be more or less sealed, otherwise it's just a waste of electricity as all you're doing is trying to dehumidify the world.
If you manage to more or less seal the van, the type of dehumidifier you use is important, a refrigerant dehumidifier is pretty useless when the air is cold. Far better in a cold climate are the desiccant dehumidifiers. 
We have one in our conservatory, works fine so long as the doors are shut.
Al.

Gromit, In broad terms you can substitute "humidity"  for vapour pressure. OR more accurately you should substitute "relative humidity". …. which is .. the ratio of the pressure of water vapour present to the saturated vapour pressure. In this argument the temperature is constant and pressure refers to the tendency to equalise different levels of humidity .  It is not a mechanical expression.
So the damp area will have a high level of moisture present and the air in the van will have less moisture present. Vapour pressure exists between them.  The bigger the difference the bigger the tendency for moisture to be drawn out..pressure !
I should add that a colleague once concluded an involved argument by saying "Well, I'm still confused but at a much higher level" !!!

I understand all that thanks Keith, and like many physical or chemical reactions the gradient dictates the pace.

What I don't understand is how you expect to make much difference when trying to dessicate the inside of a huge colander. As Al said above (and others, including me ) if the van was more or less hermetically sealed a dehumidified would be quite effective - eventually.

Trouble is there are so many holes the poor little gadget doesn't stand a chance.

In conclusion however, a dehumidifier won't make matters worse, so there's nothing to lose by giving it a go.