What is causing this? Rising damp or salts?

[Tony Stafford]

Had our hall plastered about a year ago. Couple months later this mark appeared. This is an internal wall. I think it's salt trapped in wall, would I have to get replastered or is there anything I can do. Thanks

 

[bobasd]

ask the mods to transfer this to the building forum.

basicly yes you will have to hack off to one metre highback to brick and render back up with a sand and lime render.remove the skirting and examine it for rot.
is that a suspended floor or a solid floor?whats on the other side of the wall?is there a chimney breast nearby?

 

[KenGMac]

Looks a lot like rising damp?

What age is the property?

 

[Tony Stafford]

The property is around 100 years old. It's a Victorian terrace. The other side of the wall is the dining room, it has a radiator on it, no chimney breast nearby. The floor is suspended. Some air vents were blocked which I have now cleared, which I suspect havent helped.

Many thanks for your replies.

 

[TicTac]

Why was it plastered last year.

 

[bobasd]

examine the floor boards near the wall.if you can, go under the floor and examine the joist ends where they sit in any wall. look for wet rot.
that doesnt look like a ventilation problem more like rising damp or a leak from a rad pipe.good through ventilation is a good idea though

 

[Tony Stafford]

Due to the age of the property some of the walls had hairline cracks and artex on the ceilings, so for cosmetic purposes thought it would be best to plaster the whole hall/ landing.

 

[TicTac]

Follow Bobs suggestion, and lift the floorboards. The wall looks wet enough to suggest a water leak - are there CH pipe under there, and has the system been losing pressure.

 

[Tony Stafford]

Thanks both very helpful.

It doesn't feel wet and the skirting isn't wet (I think the picture makes it look a little darker than it is). I will check the joist ends tomorrow.

Is there any chance it could be trapped salt in the walls drawing out the moisture? As it does have a white ring mark on the outerside of the patches.

 

[TicTac]

More than possible, but it's also rising from the floor, so can go either way. It'll still need redoing though.

 

[foxhole]

I would suspect leak from heating pipework, or possible mains as it usually enters property under hall ways.