Dampplug Calling PigletJohn

[dampplug]

@PigletJohn
Please could you help me!

I have this damp patch on my wall. It is an internal wall, the skirting board you can see at the bottom of the photo is ground level.

The other side of the wall isn't damp and the damp patch isn't touching the skirting.

It's been there a couple of months and seems to be spreading out slowly.

I'm very confused

it looks to me like a wall that is plastered and has painted lining paper or wallpaper on it. The water seems to be coming from the socket. I surmise that water is either coming down the electrical conduit (if any) or the hole for the socket backbox has caused some damage. My first thought was tanking in a cellar, but you say this above ground. Are there any radiator pipes nearby? Are the pipes the size of a pencil, or of a finger? Do you know of any pipes concealed in the wall?

If you are competent with electrical work, I would remove the socket and see what can be seen. power must be turned off at the consumer units. Water and electricity can be a fatal combination.

The socket is not level and does not look securely fixed, which suggests lack of skill by the installer.

Conduit can be recognised because there will either be a plastic tube penetrating the backbox, or a large metal nut that is used with metal conduit; and the cables coming out of the nut(s) or conduit(s). If the cable comes from above there is probably a leak above it, for example in a bathroom. Look at the wall in the room directly above this one for any signs of water.

It's not on a chimneybreast, is it?

How old is the house?

Thanks so much for your reply.

House was built 1940s ish. It's not a chimney breast.

Above this wall is the roof, it's a dormer bungalow but if it was coming in from the roof wouldn't the top of the wall be wet?

I will get dh to take the socket off when he is free.

Thanks for your advice

are there tanks or pipes in the loft?

It's a loft conversion, no tanks, but plenty of pipes, radiators etc.

To answer your question about wouldn't the top of the wall be wet, water can sleep through tiny gaps/holes and it tracks to the lowest point it can get to, which is why PigletJohn has suggested it could be coming down conduit or the electrical cable. Then it hits something it can't track down and seeps through the plaster to the surface.