There's mould on my ceiling
A brown stain, a patch of black mould or sagging plaster on the ceiling is a sign water is getting in from above. In a single-storey house that's often the roof or gutters. Under a bathroom upstairs, or in an apartment, it's usually plumbing. Either way, ceilings can hold a surprising amount of water before they show it, so it's worth finding the source quickly.
Where the water comes from
Bathroom above
A leaking shower, bath waste or toilet connection upstairs drips onto the ceiling below, often showing up as a stain right under the bathroom.
Pipes in the ceiling
Water and hot water pipes run through ceilings in many homes. A pinhole leak or failed joint drips steadily.
Hot water unit in the roof
Some older homes have the hot water system in the roof space. A leaking tank or relief valve can soak the ceiling.
Gutters and roof
Overflowing box gutters, blocked downpipes and roof leaks show up as stains after rain.
Condensation
A bathroom without good ventilation can grow mould on the ceiling from steam alone. It's usually spread evenly rather than one stain.
Clues to the cause
- Only after rain: likely gutters, downpipes or roof.
- After showers or baths upstairs: likely the bathroom above. See bath leaking through the ceiling.
- All the time: likely a pressurised water pipe. Do the meter test in our hidden water leak guide.
- Sagging or bulging plaster: keep clear of the area and get it checked quickly.
How we find it
We work out when the leak happens, test the water pipes, run the fixtures above one at a time, and use moisture meters and thermal imaging to track the water to its source. Then you get clear options and a fixed price before any work starts. See leak detection.
In southern Eastern Suburbs homes
Two-storey homes in Maroubra, Coogee and Little Bay, and units in Kensington and Kingsford, are where we most often trace ceiling stains to a bathroom upstairs. In older single-storey homes in Matraville and Botany, a hot water unit or pipes in the roof space are common culprits.
Why locals call us
- Local to Matraville and the southern Eastern Suburbs
- Free on-site quotes, with a fixed price before any work starts
- Lifetime labour warranty on our workmanship
- 100+ five-star Google reviews
- Licensed plumbers and gasfitters (Lic. 398171C)
Common questions
Why is there mould on my ceiling?
Water is getting in from above: a bathroom or pipe leak, a roof or gutter problem, or condensation from poor ventilation.
How do I know if a ceiling stain is from plumbing or the roof?
If it only appears after rain, it's likely the roof or gutters. If it appears after showers or all the time, it's likely plumbing.
Is a sagging ceiling dangerous?
It can be. Wet plaster can give way. Keep people clear of the area and have it checked quickly.
Can you find a ceiling leak without cutting holes?
Usually. Moisture meters and thermal imaging narrow it down first, so any opening is small and in the right place.
Related help: leak detection, bath leaking through the ceiling, mould on walls, blocked downpipes and hidden water leak guide. Local pages: Maroubra, Coogee, Kensington and Little Bay.