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
--
Chris J Dixon Nottingham UK


Plant amazing Acers.

On 24/08/2016 20:45, Chris J Dixon wrote:
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

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.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 8/24/2016 9:31 PM, Roger Mills wrote:
On 24/08/2016 20:45, Chris J Dixon wrote:
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

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.

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.

On Wed, 24 Aug 2016 20:45:41 +0100, Chris J Dixon wrote:

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?

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

newshound wrote:

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.

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.

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.

Indeed

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.

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 Nottingham UK


Plant amazing Acers.

Thomas Prufer wrote:

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...

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
--
Chris J Dixon Nottingham UK


Plant amazing Acers.

On 25/08/2016 06:11, Thomas Prufer wrote:
On Wed, 24 Aug 2016 20:45:41 +0100, Chris J Dixon wrote:

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?

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

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

Chris J Dixon wrote:
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


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.

On 8/25/2016 8:24 AM, Adrian Brentnall wrote:
On 25/08/2016 06:11, Thomas Prufer wrote:
On Wed, 24 Aug 2016 20:45:41 +0100, Chris J Dixon
wrote:

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?

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

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

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

After serious thinking Chris J Dixon wrote :
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.

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.

newshound explained on 25/08/2016 :
+1, I used it successfully on (IIRC) a Citroen CX windscreen.

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