IN SHORT
- Ceiling mould often comes with a musty smell, even before it's obvious.
- Check the roof space for leaks and water tracks.
- Check for condensation, especially in bathrooms and under cold roofs.
- Check air conditioning ducts and drainage.
Mould on a ceiling can be black, green, white, grey or brown, or even pink, orange or yellow. If you find it up high, don't panic, but don't leave it either. Whatever is feeding it is likely to keep feeding it.
1. Water getting in from outside
After storms and heavy rain, ceilings are vulnerable to leaks. Look in the roof space for water tracks, stained timber and wet insulation.
- Check the roof itself and the flashings around anything that passes through it.
- Check gutters and downpipes for blockages that can push water back under the roof.
- Growth in a line often follows a water track.
2. Condensation and ventilation
Warm, moist air rising to a cold ceiling condenses, and that moisture is a common trigger for mould. It is especially common on bathroom ceilings.
- Make sure exhaust fans vent outside, not just into the roof space.
- Gaps in insulation and uninsulated metal roofs can create cold zones where condensation forms.
3. Air conditioning
If mould is spread across several rooms or comes back quickly, the air conditioning system is worth checking.
- Ductwork in the roof space can collect condensation and spread moisture and spores between rooms.
- Check that the indoor unit drains properly and isn't dripping into the ceiling.
Before you clean
If the affected area is larger than about one square metre, keeps returning or sits on plasterboard, have it assessed professionally. Avoid dry brushing or scrubbing, which can release spores, and deal with the moisture as well as the mould.
WHERE DRYSAFE FITS
Our packages cover affected vertical surfaces. Ceilings, window sills and door and window tracks are covered by the HomeProtect upgrade, and every job includes moisture and humidity readings and a written works report.