nog wrote in message .. .

We have a basement below about one-third of the house and its usefulness
for storage is limited by damp, and resulting mould spores.
We've tried to combat this by using a de-humidifier but I suspect the net
result of this is to accelerate the rate at which water is vapourising
through the walls.
Would we have more success by installing one or more extractor fans to pull
air through? The floor area in question is about 45 square metres, split
between two rooms, with a ceiling height of about 2 metres. The remaining
space under the house is just crawl space, although fairly generous in
headroom. The house was built around 1910.


Yes, and much cheaper to run. Downside is youd lose any heat down
there, and heat isnt free.

Better than fan is unfanned ventilation: if you can arrange it its
silent, reliable and costs nothing to run. Need 2 openings for the air
to blow through, 1 opening isnt gonig to achieve much - same with fan.

If its just a case of the dehumidifier not being effective enough, I
imagine a ceiling fan on low would help a fair bit - have never tried
that, but I would thihk it would.

Another option is to tar the walls, then the space would be far more
useful. There are also clear waterproofing compounds available for
sound substrates.

Regards, NT