How to deal with surface damp
Tuesday, 20, Sep 2016 04:12
by Ed Davies
Following on from our previous feature on water ingress, we now turn our focus to the less serious yet ever-present, slightly vexing conundrum of surface damp
Surface damp like Christmas and taxes, I am afraid, is a fact of life. If you own a caravan, the chances are, you have had or are going to get damp patches. The good news, however, is that it is normally nothing to worry about.
The problems it causes are not structural and prevention is easy. So relax, sit back and allow us to, yes, de-mystify any bad advice you may have received.
The real cause of damp is the fluctuation of temperatures throughout a day or course of a year.
As most of us know, at higher temperatures water molecules will turn to gas and at lower temperatures they will return to liquid form.
So, during the day when temperatures are higher water will evaporate but when temperatures drop at night it condenses becoming liquid again on the interior of the van.
This is why many people will testify that on waking from their first night's sleep in a caravan they can feel damp in the table or soft furnishing. This is simply condensation.
If you open the door, window or switch on your heating this will go in a matter of minutes.
But why does black mould grow?
Mould spores are everywhere in the air and will grow on just about anything if they have water and light. So when a caravan is not used regularly and is poorly ventilated it is fertile ground for mould to grow.
Imagine a situation where you return from your summer holiday on a lovely sunny day and you close the caravan door.
The caravan is full of lovely warm air containing large amounts of gaseous water. You leave the caravan for months and as winter comes the temperature drops and the gas slowly becomes liquid.
As the air is not replenished and the water remains stagnant, mould has the perfect place to thrive and grow.
As the crux of the matter is ventilation, the easiest, most effective and most enjoyable way is to use your caravan as often as you can all year round - believe me, as a man who has stayed at a ski resort in a caravan and motorhome, it is a brilliant winter break.
If that is something you are unable to do then you need to supply the interior with fresh outside air at least once a month.
However, that does not mean simply opening your caravan's window for 10 minutes. The likelihood is that you will need to ventilate it for a far greater length of time.
You might consider sleeping in it overnight. A lovely, relaxing, romantic night on your own driveway.
If this is not possible or desirable, it is recommended you open up all the windows and doors in your camper, make a cup tea and wait for around an hour before you seal it up again.
The only other thing you can do to help is to open all cupboard doors when you leave your caravan for a period as this prevents high moister microclimates developing.
Beware Poor Advice
Often have I heard that cleaning your caravan regularly is a sure fire way to eradicate the growth of mould. Wrong.
As we have said it is not dirt but water that mould thrives on. If you leave a piece of bread on your kitchen side it will go mouldy but once the water has gone the mould will die.
Likewise take a glass of water and leave it for week on the side with nothing in it and it will start growing mould.
Ironically cleaning your camper will deter the mould, but would, in fact, be no more effective than teetering about in it alone for an hour or two, playing a game of cards or reading a magazine - the choice, as ever, is yours.
With cleaning dealt with, another oft mentioned remedy is removing all the soft furnishings to stop mould developing.
Although soft furnishings do hold more water and are therefore more likely to go mouldy removing them will only prevent them themselves from becoming mouldy.
Dealing With Mould
Here is where, for once, cleaning might actually come in handy. If you do get patches of mould they will need to be removed with mould removal spray, which can be bought from any Homebase store.
It is worth doing it properly, checking under beds, the backs of cupboards and lockers.
However, once all mould is removed, there is truly no use in simply locking up the caravan for another three months until it is used again as the mould will just come back.
So, if you love your caravan or your motorhome, you cannot simply leave it alone and untouched for months.
Like an elderly relative, you will need to visit it, have a cup of tea with it, play a game of cards or even, if you want, have a chat with it.
If you manage to do that, it will remain a happy, lovely, mould free camper for as long as you want.