condensation

[Scarlett]

I have had a very black, speckly ceiling in my bathroom for a few months due to condensation.

However, it has VANISHED!! How can this be? It hasn't rained for ages, and it has not been cold, but how can the black marks simply vansish? Where have they gone??!

[buildersmate]

You have correctly diagnosed the answer, but from the wrong starting point. It is simply because it HASN'T been cold that the mould growth has disappeared. Moisture comes from your shower or bath, rising up to the ceiling and condensing on the cold surface. The damp surface is ideal to then attracts mould spores. When the temperature falls I fear it will return. Solutions involve trying to raise the surface temperature of the ceiling (can you put a bit more insulation above it?) or painting it with Kitchen/Bathroom paint (which are formulated to seal the porous surface of the plaster and discourage spores from settling).