Whats this mark on my wall ?

Quigs Snr

Any idea what this is ? This is an internal dividing wall between two rooms in the house.

Plaster has been in place about 2 years (old house... new skim coat of plaster went over old... this stuff only started happening a cpuple of months ago)


https://ibb.co/vsbn9vj

https://ibb.co/Khngz5w


Its about a 30 foot long wall which doesnt touch any external wall.. on the other side of it at one end there is a small room.where the laminate floor is lifting a bit.. bad picture but its like elliptical waves coming out from the wall. Probably the underlay is swelling.

But why ?

Penetrating dampness ? A burst pipe somewhere ? Any ideas ?

https://ibb.co/swjqj9W

The Continental Op

In a word efflorescence, but the question is why?

First there has to be moisture but that doesn't mean there has to be a leak. Any chance water is condensing on a cold radiator pipe within the wall?

Quigs Snr

The Continental Op wrote: »

In a word efflorescence, but the question is why?

First there has to be moisture but that doesn't mean there has to be a leak. Any chance water is condensing on a cold radiator pipe within the wall?

Looks like the radiator pipes are through the floor.

Perhaps some candidates are : Water trapped from a radiator leak upstairs which occurred 2 years ago and could be seen as black streaks in the cracks in the original plaster before it was replastered.. but I see no marks about say 2 feet.. and these are 9 foot walls, so that seems odd.

And it doesn't really explain the floor lifting in the adjacent room (with some skirting turning black in there also).. so maybe rising damp.. or a leak in a pipe somewhere in the floor ?

I wonder therefore is it some form of rising damp either a leaking pipe

mehico

Is it near any shower by any chance? Leaking shower water could seep down to the sub floor and travel along before hitting the wall and causing the water to then pool at a low point (if the sub floor is not completely level in this area) and then make its way up through the wall.

fred funk }{

You 100% have a leak somewhere.

Quigs Snr

mehico wrote: »

Is it near any shower by any chance? Leaking shower water could seep down to the sub floor and travel along before hitting the wall and causing the water to then pool at a low point (if the sub floor is not completely level in this area) and then make its way up through the wall.

There is a shower upstairs bit not directly overhead and best I can tell it drains on the opposite corner to where this is.

Quigs Snr

Sketched a rough floor map.. red lines are walls that show signs of efflorescence. Green walls so far show none.

https://ibb.co/ZJHXyvb

And the semi coloured in red room is the small office where I first noticed floorboards warping a few months ago and one joint in the skirting starting to look a little black.

As you can see its an internal wall. Radiator pipes seem to run underground.. more or less in a straight line... house is two storey and this is the ground floor.. no sign of issues upstairs that I have found yet.

Room on the far left is a recently converted garage that seems to have no issues.

... I have a feeling whatever this is. Its gonna hurt to fix it.

listermint

There's too much going on here in a few months for it not to be a leak. Either central heating or the water supply . One or the other is dripping into the floor at a relative high rate meaning it's constant.

Reasonable first step if you have an open vented heating system is to tie up the ball cock for a week and measure the drop in water.

policarp

Was any work done around the house?
If so could be rising damp.

ted1

If you could get your hands on an thermal camera you should be able to see what’s happening and follow a leak. You should be able to rent one

https://www.flir.eu/discover/professional-tools/how-to-detect-a-water-leak-with-thermal-imaging/

Quigs Snr

policarp wrote: »

Was any work done around the house?
If so could be rising damp.

Not in the last 2 years.

CJhaughey

If that radiator pipe is bare copper it may have corroded away and started to leak, the brown colouration would also seem to be from radiator water.
I would start with testing the heating system for leaks and go from there.

10-10-20

OP, you said "old house", but do you know what the make-up of the floor are?
Is it raised boards on block, or direct on soil/stone? Were the floors re-poured during recent works? Do they sound hollow, etc?

Quigs Snr

10-10-20 wrote: »

OP, you said "old house", but do you know what the make-up of the floor are?
Is it raised boards on block, or direct on soil/stone? Were the floors re-poured during recent works? Do they sound hollow, etc?

Floors were not re-poured. Seem to be entirely solid. We had to dig to re-situate a radiator in a different room on the far side of the house and that was a Kango hammer job. When I took the boards up they just looked like concrete.