Sealer tape

[Chris J Dixon]

My caravan, now nearly 10, is showing slightly raised damp readings in part of the roof. I know from experience that internal dampness doesn't necessarily indicate the point of ingress, but that section of roof is essentially flat, and has a join covered by an aluminium strip secured by many screws.

The screws are effectively irremovable intact, and I don't want to create a big job when this might not even be the source of any ingress.

I have already applied sealant around the joint strip, and don't really want to add more, but I wondered if anyone has experience of a suitable sealant strip (eg Sylglas) I could apply over the whole joint?

Chris

[Roger Mills]

Caravans are notoriously difficult to seal and, once there is a measurable amount of damp in them, there's little you can do without a major strip and re-built. BTDTGTTS! The damp wood will go on rotting even - in the unlikely event - that you *can* stop any more getting in.

How long are you intending to keep it? The options are to spend a *lot* of money on it and then keep it for at least another 10 years or unload it now - so that it becomes someone else's problem.

[newshound]

Don't disagree with what Roger says, but I'd have thought either the aluminium waterproofing or clear weatherproofing tapes made by Sylglas would be relatively cheap and easy options, and should at least sort out that joint.

When you say "raised damp readings", do you mean resistance measurements on timber or timber-like internal cladding? I've not much regard for these instruments in checking damp walls, and in your case might be indicating condensation especially if the cladding has become a bit porous with age.

[Thomas Prufer]

There is something called "Captain Tolley's Creeping Crack Cure". If it does what it says on the website, this is for you -- but I know nothing of it beyond what it says there. I know of this Cure only because I did not believe there was actually a product of that name...

Thomas Prufer

[Chris J Dixon]

I understand what you are saying. My last van managed 25 years, despite having had a leak or two early on which I fixed, and lived with some spongy timber afterwards.

I am sticking with a moderate reaction to a potential problem.

Indeed

You might be right. I did have high readings under the front window. After trying various "cures" re-sealing the roof light seemed to fix it.

Chris

[Chris J Dixon]

Thanks. I have used that on a crack in the fibreglass of a previous van, but don't think it is right for this problem.

Chris

[Adrian Brentnall]

It's good stuff (despite the unlikely name). I used it to keep the rain outside my elderly Moggie Traveller for five years or so - it's a very thin liquid that wicks its way into small gaps and sets to form a seal. Also very handy for sealing old stained-glass windows where the putty has dried out and the client doesn't want to pay for a better solution! Adrian

[Capitol]

Not quite the answer you are looking for, but we bought a Maypole cover from Amazon which keeps the water out and is breathable. They only last 2 years before they are scrap IME. The caravan keeps beautifully clean and we have no damp problems on a 20 year old van. The only drawbacks are that the fit is not too good and it is necessary to add zips to provide door and front hatch access. The material is easy to sew on a domestic sewing machine but you need wooden fingertips to put 32M of pins in first. She has now discovered why she has a thimble collection! Zips also come from amazon. Buy 2 x 5M lenghts, it comes as one piece with good delivery. Use polyester or nylon thread.

[newshound]

+1, I used it successfully on (IIRC) a Citroen CX windscreen.

[Harry Bloomfield]

It certainly is the thing to use, for minor leaks where any gaps are stable.

If it is a modern quality caravan, the screws along the awning strip should be stainless steel, so should come out easily to allow the old sealant to be cleaned off and replaced with new.

[Harry Bloomfield]

newshound explained on 25/08/2016 :

It has always worked well for me, despite its silly name.