My upstairs bathroom leaked when the bath was drained
The kids have their bath, someone pulls the plug, and a few minutes later water is dripping through the ceiling downstairs. It's a common call, and the timing is a big clue: if it only leaks when the bath drains, the problem is almost always in the bath's waste connection or the seal around the plug, not the water pipes. Here's what usually causes it and how it's fixed.
Right away
- Stop using the bath until it's checked.
- Put a bucket under the drip and move furniture and rugs out of the way.
- If the ceiling is sagging or bulging, keep everyone out from under it.
- Take a photo of the stain and note what was being used upstairs when it started.
The usual causes
Bath waste seal
The plug and waste outlet is sealed to the bath with a washer or sealant. When it perishes, water leaks around the outside of the waste as the bath drains.
Loose or cracked waste pipe
The pipe and trap under the bath can work loose or crack, especially if the bath has moved slightly. A full bath draining puts a lot of water through it fast.
Overflow connection
The overflow outlet near the top of the bath connects to the waste. If its seal fails, a very full bath leaks through it.
Splashing and failed grout or silicone
Kids splashing water over the edge, and gaps in the silicone where the bath meets the wall, let water run down behind the bath and through the ceiling.
How we fix it
We test the bath by filling and draining it while watching from below, check the waste, trap and overflow, and look at the seals around the bath. Most of the time the fix is a new waste and seals, or re-securing the pipe under the bath, sometimes through a small access hole in the ceiling below rather than pulling up tiles. You get clear options and a fixed price before any work starts.
In southern Eastern Suburbs homes
We see this most in two-storey homes in Maroubra, Coogee, Little Bay and Pagewood, and in older units in Kensington and Kingsford where a bath sits above someone else's ceiling. Bath wastes that are twenty or thirty years old are often the cause.
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 does my bath leak through the ceiling only when it drains?
The leak is in the drainage side: usually the waste seal, the pipe under the bath or the overflow connection, rather than the water supply.
Do you need to rip out the bath to fix the leak?
Usually not. Most leaks are fixed by replacing the waste and seals, sometimes through a small access hole in the ceiling below.
Can splashing cause a ceiling leak?
Yes. Water splashed over the edge can get behind the bath through gaps in silicone or grout and reach the ceiling below.
Will the ceiling need repairing?
If the plaster is badly stained or soft, it may need repair once the leak is fixed and it has dried out.
Related help: mould on the ceiling, leak detection, toilet leaking at the base and taps and toilets. Local pages: Maroubra, Coogee, Pagewood and Kensington.