I have a first floor flat, with an entrance hall downstairs on the
ground floor. The flat has gas central heating and radiators in all
rooms except for the downstairs entrance hall. The downstairs
entrance hall smells musty and is cold and I have to regularly clean
to door as mould starts to form.

At first I thought the problem might be with the damp proofing, done
some 5 years ago. So I called in the damp proofing company to inspect
under their guarantee. They confirmed that the damp proofing course
was fine, but that the problem was due to condensation produced by
washing machine, dishwasher, cooking, clothes drying etc.

The recommended solution is to put in an extractor fan that detects
when the level of moisture is high, and then extracts this to outside.
So far so good! The damp proofing company has recommended that this
extractor fan is put in the upstairs kitchen (which is some
considerable distance away from the downstairs entrance hall), the
rationale being that this is where most of moisture in the air comes
from.

As the work will cost £300, I just wanted to double check here with
the experts, that an moisture triggered extractor fan in one room,
will sort out the problem for the whole house. I'd appreciate a
second opinion.

Has anyone else had experience of such a solution, or can offer any
advice.

Thanks in advance for any advice given.

Best Regards,

Robin