Mould stains at edge of bathroom ceiling

[Longshanks]

Hi

Edge of bathroom ceiling constantly showing black/mould stains. Have painted over several times but these always quickly return.

I’d previously understood it could be poor insulation at the edge of loft resulting in colder surface at that point.

It’s a conundrum, as deliberately left a few inches between insulation and eaves. Also looks to be adequate height at that point. (Also no staining at edge of adjacent bedroom)

Have extractor fan in bathroom.

Any wisdom would be appreciated.

Thanks

 

[JohnD]

Your bathroom is damp. Do you have steamy showers?

What sort of extractor do you have, and when do you use it?

The wall is probably cold. Is it a cavity wall?

Show us the eaves and insulation. You can get eaves vents that keep the channel open and allow insulation up to them.