In message , Mike Halmarack
writes
On Fri, 22 Nov 2019 21:16:46 -0000, "Brian Gaff \(Sofa\)"
wrote:

What is causing the mould. That is the question.
The problem is that the spores will just seed somewhere else usually and so
the main thing is to find the damp source and stop it first.
Brian

The main contributor seems to be condensation.
Recently moved into an electric only flat and are waiting to see our
first bill that includes heating, before investing in electrical
solutions like dehumidifiers or powered extractors.

Might be useful to discuss the problem with neighbours in similar flats.

Way back we had a thread on extract heat recovery. This was related to
issues of condensation in a North facing, 60's build, uninsulated cavity
wall block.

Where clothes drying, excessive showering, cooking etc. put lots of
moisture into the air which promptly condensed on the cold upper parts
of the North walls.

Luckily the flats were commonhold and nobody objected to us putting in a
central heat recovery system plus extractors for bathroom and cooker
hood.

Having bought anti mould spray from Lidl and then treated the
offending patches to a double dose, it may be that ordinary emulsion
would be sufficient to cover the treated areas.

The idea of now painting these areas with anti mould paint may be
considered as a belt and braces approach but I wouldn't want to be
spraying unpleasant chemicals around the place too often in future.

As some of the affected rooms are decorated with different colours,
I'd prefer not to buy multiple pots of different coloured anti mould
paint, which are available.

Just one colour that was overpaintable with ordinary emulsion would be
preferable.

--
Tim Lamb