What sort of damp is this?

[Notch7]

It may be that the walls are very cold, last few days we’ve had very cold days and then warmer.

If it’s simply walls getting cold then plaster absorbing moisture through condensation, insulated wallpaper like wall rock might be a good solution (I appreciate that may be difficult in your family circumstances)

I am sorry to hear you are bedbound and things are tricky, I hope you get a solution to the damp

 

[accelerator]

OK but I would still think water is getting into the wall somehow. Without us knowing exactly the layout of the house or the surrounding ground/drainage, it's hard for us to say what it could be, but I do still think it is likely to be a rising damp issue rather than a condensation issue.

 

[accelerator]

As they appear to be concrete walls, then I guess it could just be cold transmitted from the ground, which would explain why the mould is only low down.

Are you heating the room?

 

[noseall]

Unfortunately, more likely to be rising damp in my opinion,

Black spot mould is exclusively a condensation issue.

We have a house built in the late 1970s. It is an ex-council house with cavity brick walls on the outside that have been filled. Internally most walls are made of concrete blocks and some stud walls. I think there is a concrete floor underneath the under the fake plastic floorboards.

Three or four years ago we found the under stairs area was sodden from an internal tap. The next day we were going on holiday so we just moved everything and left the internal doors open. When we came back we found that there was mould on the walls in the living room. I just washed them down and put a dehumidify on to dry them out which didn't completely remove the mould stains.

Now a few years later we have found that the black mould is back. Last year we had some black mould on a wall underneath a window, so an external wall, where boxes were touching that wall. The boxes were moved but the walls still sometimes gets damp.

A few months ago we found some more mould behind sheets of cardboard that have been touching an internal concrete block wall for years. The wall was also damp to touch. My wife just threw the boxes away and left it. There is a radiator on the other side of this wall in the hall.

Today my wife found some more black mould on another wall, which I think is a stud wall, where some books and films had been pushed right against the wall. Again the wall was damp to touch and looks wet.

These walls were where there was black mould before, when we had the leak, which was in the hall under the stairs.

There is a radiator in the lounge but it's in the opposite corner to where the black mould is. Also my wife currently sleeps in the lounge as I am bed bound and it's easier. I would guess that because she sleeps there is more humidity in the room at night. On the opposite side of this wall is an internal walk-in cupboard which has no heating, though its door is always open.

In both these cases the black mould goes to about a meter above the floor. We constantly have a dehumidifier on in the hall as we dry our washing there.

Unfortunately I am not able to go downstairs and look and my wife is worried about her and our children's health. Our whole house ia crazy and my wife constantly hectic.

Is this black mould more likely to be due to condensation as no air was circulating between the walls and cardboard/books that were touching them, or is it possibly rising damp?

I have attached a few images of the latest spot. Thank you.

First and foremost your walls need insulating. As said, diligent and optimal venting will help.

 

[noseall]

Drying clothes indoors, is guaranteed to produce mould

As is the occupants breathing out.

 

[accelerator]

Black spot mould is exclusively a condensation issue.

First and foremost your walls need insulating. As said, diligent and optimal venting will help.

Yes, I understand that condensation is involved, but what I am saying is the wall is getting too wet and/or cold which then makes the condensation happen. It is a combination of wet and/or cold wall, plus too much water vapour being generated inside. Yes, insulating the walls would work, but you need to check the walls aren't getting wet from a ground source or something else first.

 

[noseall]

Yes, I understand that condensation is involved, but what I am saying is the wall is getting too wet and/or cold which then makes the condensation happen. It is a combination of wet and/or cold wall, plus too much water vapour being generated inside. Yes, insulating the walls would work, but you need to check the walls aren't getting wet from a ground source or something else first.

Blackspot mould needs water lying on the surface (wet surface) to feed. Damp walls alone isn't enough. The two types of damp and how they manifest, are quite distinct and so is the diagnosis and remedy.

Granted, there could also be rising or penetrative damp (disguised by other forms of damp) and that would need looking at also.