DIY Doctor UK DIY Forums

We've lived in our 1900 terrace property for over 3 years and have not had damp problems to date. At the beginning of last week we noticed a fairly strong odour when we came home and on Friday we noticed black mould appearing on the adjoining wall with our neighbour.

The mould is in the centre of the wall and is at the top near the ceiling; so far we have not been able to catch our neighbours in to establish the root cause.

We have no pipes in this location, they run through the centre of the house and as it's an interior wall, we do not think this can be down to a leaky gutter.

The neighbours only moved in 3 months ago and shortly before then the previous neighbour installed new furniture in the bathroom, (including a very noisy jacuzzi bath :x ). The wall with the damp problem is situated directly below their bathroom. Is it possible that a leak on their side could be causing the problem?

You only get black mould from fresh tap water or rain water.
Your suposition is undoubtedly correct, it is their problem.
However, they probably don't know its happening.
So, a gentle approach is required.
Best of luck.
Perry525

Many thanks for the information. It turned out to be something not quite so problematic.

When the previous occupants fixed their leaky gutter before they moved, they knocked some tiles loose on the sloping roof that joins our two kitchens together on the ground floor. Unfortunately, they didn't put it right/notice they'd done it and so both houses were left with a gap big enough to get your hand down.

It seems to have affected our house more than the other, but now that we know what the problem is, I'm assuming we just have to dry the plaster out (we've already repaired the roof).