Black stains on Bathroom ceiling

[thediynovice]

Can anyone please advise me how to stop the bathroom ceiling turning black around the edges.

I believe it's caused by the damp air, even though we have a small extractor fan and regurlarly leave the window open.

Every time we wipe it off and paint over it, it comes back after a few months.

Any tips?

 

[JohnD]

if it is black mildew.

//wiki.diynot.com/building:condensation_in_houses


If it is pattern staining, and nobody smokes in there, there is a slim chance that the edges are cold because the loft insulation has been carelessly fitted.

p.s. "Having" a fan and "using it all the time the bathroom is in use" are not the same thing. Many people have a psychological aversion to ventilating bathrooms and will not turn the fan on. I favour switching them with the light switch.

I hope no-one leaves wet washing or towels in there or draped over radiators with the window shut.