Common situation
Bathroom mould that keeps coming back after cleaning
If black spots come back within weeks of cleaning, cleaning harder isn't the fix. Something keeps that surface wet, and that cause needs finding.
What it usually points to
Mould that returns within weeks of cleaning means something keeps that surface wet. Black spots that come with damp or a musty smell are usually mould, which means a surface stays wet for long stretches. This page can't confirm what they are. Without a humidity reading we can't tell how damp the whole home is.
What to check and try first
- Tell whoever looks after repairs, with a dated photo, that it has come back after cleaning. Returning mould usually means a cold wall, poor extraction, or water behind the surface.
- With no working fan, open the bathroom window during showers and leave it open until the mirror and walls have cleared. Keep the door shut and wipe the walls dry.
These steps assume only: black spots, possibly mould, on a ceiling, wall or window frame; shower or bath with no working exhaust fan; mould came back within weeks of cleaning. Your home may be different. Add what else is going on and you'll get steps for your situation.
Check my home with these answers
What would change this
If it spreads past a dinner plate or onto a second wall, or anyone's breathing or allergies get worse, chase the repair in writing and talk to a GP.
Read next
- When damp or mould needs a repair or a professional
- Indoor humidity: what the number tells you
- How to read a dehumidifier's litres per day