Why the ceiling?
Steam rises and the ceiling is usually the coldest surface in a bathroom, especially under a loft or a flat roof. The moisture condenses there, and if the room does not clear quickly, mould grows. Corners above the shower and the area around the window get it first.
Check your extractor fan
Hold a single sheet of toilet paper up to the fan while it runs. If the fan does not hold the paper against the grille, it is not pulling enough air. Also check whether it keeps running after you switch the light off. Many do not, and in a lot of older homes the fan vents into the loft rather than outside.
How to clean a small patch yourself
- Open the window and wear gloves, a mask and eye protection.
- Use a mould remover spray, not neat bleach, and follow the label.
- Wipe with a damp cloth, do not dry brush.
- Let the ceiling dry fully before painting.
- Use a stain block primer then a bathroom anti mould paint.
When to get it done professionally
If the mould covers more than a small patch, keeps returning, or the ceiling paint is peeling, a full treatment and a better fan is the lasting fix. See bathroom mould removal.
Questions people ask
Is bathroom ceiling mould the landlord’s problem?
Last reviewed 15 November 2026 by the Home Damp and Mould team. Read our editorial policy.