3 Jul 2014
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United Kingdom
Does anyone have any idea why this damp patch is happening? It's an internal wall in the hallway. We had the walls replastered and this patch has started to appear. Is is rising damp? It's weird how the damp is around the socket.

Any help greatly appreciated!
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Work has previously taken place in the hallway - the skirting is relatively new, and doesn't meet the stair string.

Why did you have the wall re-plastered?

What about leaks to the CH system?
Hi- we had all the walls replastered for the house as they were all in a bit of a state. The wall adjoins another property. I presumed there wouldn't be leaks from the ch as no pipes behind the wall...
Many thanks
This happened to a mate of mine, he just left it for two months and it dried out. One of lives little mysteries?
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You have a rad and pipes below the floor - your neighbour might have a similar set-up.

Given that you dont report any signs of a previously damp wall then its probably best just to wait and see until, say after winter.

If it expands or gets "worse" then come back here.
It is likely to be condensation caused by a cold wall in an unheated space, which communicates with warmer living spaces upstairs. It will disappear if the radiator is turned on, and when the weather outdoors gets warmer and drier, until the autumn.

The damp is around the socket because the metal wall box is in contact with the colder brick wall behind and may have a conduit beneath which allows cold air from the underfloor space to pass into the box.

The visible boundary of the damp patch rises behind the radiator, where the airflow is limited by the presence of the radiator. The radiator is full of cold water which connects to pipework beneath the floor. I'd guess the hidden pipework is not lagged, and a source of heat loss, especially when the heating is turned on.

The damp patch extends along the skirting board until the bottom of the staircase. There are little voids behind the original skirting, which also connect to the underfloor airspace, and have brick wall behind.
Thanks everyone for all you helpful replies. I now wondering if it might have anything to do with the fact the house next door has been empty for a couple of months as well. I will leave it and see if any better in couple of months.
Many thanks again
It is not condensation. There are no indicators of typical condensation, and to suggest that condensation exists behind that radiator is ludicrous.

Maybe the rad has been on 24/7 (people often turn the heating on after plastering), maybe the wall was re-plastered last week, maybe the floor is solid- we dont know, the OP has not supplied such information.
Hi again,

The damp problem I had disappeared over the summer and now has come back with a vengance. The house next door which the wall adjoins has had bad damp but not this wall, which makes me think it can't be rising damp.

Any ideas gratefully received again.
A pic of the wall now will help.

Could you carefully examine the hall party wall, and the party wall below and beyond the stairs, for any other traces of damp?

Any chance of you going into your neighbour's hall and taking a pic of the other side of the party wall?

Have you been under the hall floor and examined conditions there? Why not lift a floorboard and have a look - check the condition of the joist ends that run into the party wall.

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