damp cold plaster

[pocketchimp]

Hi everyone,

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??

[Mike]

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.

Mike

[pocketchimp]

Hi Mike

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 any way.

Cheers Dan

Mike wrote:

[superspit]

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.

[Vødkäjéllÿ]

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 skip :-)

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? :-)

Vj

[calums]

VJ 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 become porous. Calum Sabey (Newark Traditional Kitchens 01556 690544)

[Stuart Noble]

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