I have a problem with a corner of my living-room - both walls are
internal. I recently moved in and have redecorated about 6 weeks ago,
and now in the corner from the skirting board up to maybe 2 foot high
and going about 2 foot in each direction from the corner is a damp area
which is cold to the touch.
When I decorated I noticed that the area had been replastered at some
point, and the pipes for the radiator go through the wall very near to
the patch. The plaster doesnt sound hollow, although the stuff above
the replastered area does.
Can anyone suggest where to start please??
Is the damp patch where the internal wall meets the exterior?
If it's cold the damp could be condensation. I had a similar problem on
a solid external wall and it affected the internal wall to a lesser
extent, where they met.
Both are internal walls - 1 is the wall dividing mine and my neighbours
living-room, and the other wall divides my living-room and the cupboard
under the stairs. The wall under the stairs feels fine and not damp in
Is there any sign of salts on the surface of the plaster?
Damp comes in a few forms from condensation (Cold meeting hot)
To rising damp, this is where a waterproof membrane has broken down and the
damp rises up into the wall cavity (assuming it has a cavity).
You say radiator pipes pass through this wall, can you tell if it is damp on
the other side?
If so I suspect that it could be a leaking pipe inside the hole itself.
We also had a mystery wet patch on a wall downstairs once and it was
actually from a leaky compression joint upstairs that just trickled, less
than a trickle even, down along the water pipe which went through the wall
cavity and puddled halfway down the wall where it went through the studwork.
It took alot to find it, and well, we never liked the wall there anyway,
saved on re-plastering!
ALSO check that under your floorboards is a nice void, and that it's not
filled up to the brim with rubble, rubbish, old dust sheets and cement bags
breaching the damp proof course level. This happened to me when I had damp
on internal walls inour first home. The rain got in through the air bricks
in bad weather (this is where the rubbish was wettest) and instead of the
area being able to dry out it just got more and more wet and soggy over the
3 years we lived there. One Under floor livingrooms worth filled a small
Also if it's not your rad pipe leaking if it your neighbours?
Can you come back and report what it was when you find out? :-)
The damp could be cause by a number of reasons outlined above by other
posts. I am interested in the pipe theory. If the pipes are copper and
have been in contact with either cement or lime mortar then it is very
likely that the acid has eaten the copper pipes and that they have
Calum Sabey (Newark Traditional Kitchens 01556 690544)
I'd start by running the heating continuously for a day or so. The warm
wet weather hasn't been ideal for drying out walls.
As the damp is near the rad, it's unlikely to be condensation, and the
pipe through the wall would be the main suspect. You should be able to
chip away the plaster around it
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