Mould in corner of upstairs room

[bp]

HI,

I posted a question a few days ago about Damp. Since this is slight different I am raising another

I live in an end of terrace house. Upstairs in the middle bedroom I can see what looks like mould in the corner. It is black stuff that does not wipe off, towards the floor, and skirting. It goes up about

2ft up the wall.

It is in the inside corner of the room and the two walls in question are external walls. I cannot see this anywhere else in the room.. I have other rooms with corners where both walls are external, but there is no sign of that there

I am about to decorate the room so my question is. What are possible causes of this. How can I remove it and what shoud I be doing to prevent it re-occuring.

I have looked at the corner externally (not on a ladder just from ground level) and cannot see anything that looks odd (i.e. loose bricks etc). However there is SKY dish fixed to the wall further up and the wire is tacked down the wall near that area. Could this be causing it.

Thanks

Bhupesh

[Chris Bacon]

It's probably from where some furniture stood close to the wall, restricting ventilation.

Go over it with some ordinary bleach ("thin" bleach, not lavatory cleaner), dry it off, and decorate.

Anything that lets water drip or run down the wall won't help, but that does not sound significant.

[bp]

OK thanks for the quick reply. This sounds likely as the wardrobe there was a freestanding one, but had been screwed to th wall. I have tapped the plaster and it all seems sound - that is a good sign I take it?

Ok, but there is not much I can do about this is there. Moving the cable will move the problem (if there is any. But iill go up and see if the tacking has loosened any mortar/bricks etc

[Richard Conway]

One other thing. As you say the two walls are external I assume that they form a corner externally. Is there a downpipe on this corner? We had a similar problem and it turned out that the downpipe was not properly aligned with the gutter and when it rained rainwater was dripping down the side of the house.

[Guy King]

The message from Richard Conway contains these words:

Or water running down the inside of the roof timbers from a hole. Seen that several times recently.

[bp]

There is no downpipe on that corner. The guttering at the top end there. I will check next time it rains hard to see if it is leaking or overflowing due to blockage etc.

As for water running down the inside of the roof timbers, I can go into the loft quite easily. What should I be looking for. Do I need to wait for heavy rain, or is there some damage that I can look for. Note the mould is towards the floor not near the ceiling - would this be in line with this type of fault?

Thanks

Bhupesh

[Gav]

i have had a similar situation in my end terrace, the gutter was rotten and also the dryer downstairs was not vented to outside so it way causing condensation on the external walls. remedy was to vent dryer to outside and i think it cost me around £14 and an hour or so

[Stuart Noble]

I imagine you have penetrating damp so some treatment to the outside wall is essential. If it's already painted, try a solvent based masonry paint. If it's brick, consider re-pointing and applying a sealer to the faces of the bricks. Could be condensation of course but this is unlikely in the summer months.

[Guy King]

The message from "bp" contains these words:

Generally it'd be in the top, but you'd be amazed where damp can end up!

[The Medway Handyman]

Quite common to get blocked gutters at corners, so it could be overflowing from there.

[robgraham]

I would like to offer another suggestion form my own experience of suffering from black mould in a bedroom. I'lll tell the story and see if any of it matches your problem.

18th century stone cottage in Scotland - 3ft thick walls. In the 1920's the four cottages were knocked into 2, with proper suspended floors and ventilation. They also strapped the walls and put lath and plaster. The cottages may have been cold before but would have been even colder after this as they ran the underfloor ventilation right up behind the plasterwork into the roof space giving only an inch of plaster as insulation when there was a wind blowing. We had mould on every external bedroom wall as these rooms weren't heated regularly and any moisture in the house just condensed out onto the cold plasterwork.

All this plasterwork had to be ripped off and replaced with new strapping, insulation and plasterboard, and there's never been mould since.

Rob

Stuart Noble wrote: