A brown stain on a lounge room ceiling in Green Valley, under the upstairs ensuite. The shower had been regrouted twice and was still leaking. I ran it into a bucket with nothing touching the walls or the floor, and the ceiling got wet anyway. The leak was never the grout. It was the hot tap spindle dripping inside the wall every time the shower ran, and it took twenty minutes to fix.
As a South West Sydney plumber I see the same four leaking shower causes over and over, and only one of them is plumbing. Where the water comes out tells you very little about where it got in. Here is how to work out which cause you have before you pay anyone, who fixes each one, and what a leaking shower repair costs. If you want it found today, we are a leak detection plumber, no call-out fee, across South West Sydney.
Most leaking showers come from one of four places: the taps and pipework behind the wall, the screen seals and silicone, failed grout, or a failed waterproofing membrane under the tiles. A plumber fixes the first; a waterproofer or tiler fixes the rest. A ten minute test with the taps off tells you which one you have.
The ten minute test: where is the shower leaking from?
Do this before you ring anyone, because it decides which trade you need. Dry the shower out first and get someone to watch the ceiling below or the wall next door.
- Taps off, floor only. Plug the floor waste and fill the base 2 to 3 cm deep from a bucket. Leave it an hour or two. If the stain grows, the floor membrane or the waste connection has failed. That is a waterproofing job, and no amount of grout will fix it.
- Taps on, into a bucket. Empty the base, then run the shower into a bucket so nothing touches the walls or floor, fifteen minutes on hot, then cold. If it leaks now it is plumbing: a spindle, the breech behind the wall, the shower arm or the rose. Ring a plumber.
- Walls and screen only. Taps off, wet the walls, screen and tap flanges with a watering can, keeping the floor dry. A leak here is the screen seals, the silicone, cracked wall grout or water tracking in behind the flanges.
One more. If the ceiling is damp when nobody has showered for a day, a pressurised pipe in the wall or slab is leaking around the clock, and the meter test in hidden water leak detection will confirm it.
Shower tap leaking behind the wall: the plumber's part
Shower taps sit in a brass body called a breech, buried in the wall behind the tiles. Two spindles screw into it, each with a washer and an O-ring. When the O-ring or body washer wears, water leaks out around the spindle every time the shower runs, and instead of dripping where you can see it, it runs down inside the wall behind the flange. A loose shower arm thread or a failed mixer cartridge does the same. The fix is usually new spindles, washers and O-rings and a reseat if the seats are pitted. If the breech itself is corroded or cracked, tiles come off to replace it, which is quoted on inspection. A rose that drips with the taps off is the same fault, and how to fix a leaking tap has the washer and mixer detail. Shower taps come under toilets, taps and fixtures on my services list.
Shower screen leaking: the cheap one
Most shower screen leaks are not leaks in any structural sense. The seal along the bottom of the door has worn or dropped off, the side seals have shrunk, or the silicone where the fixed panel meets the tiles has cracked and gone black. Water runs out under the door onto the bathroom floor, and in a two storey townhouse that is enough to stain the ceiling below. It is the most common reason I get called out as a plumber in Campbelltown for a leak that needs no plumber at all. Seals are a hardware shop part. Re-siliconing is a Saturday morning job: cut the old bead out completely, clean and dry the joint, and run a fresh bead of neutral cure bathroom silicone. Never put new silicone over old. A frameless screen loose at the hinges or the wall channel is one for the glazier.
Leaking shower waterproofing: grout, membrane and the fix nobody wants
Grout is not waterproof. It never was. Tiles and grout are the wear layer; what keeps water out of the house is the waterproofing membrane under the tiles. Houses built before the late 1980s, and there are plenty around Liverpool, often have no membrane at all, just a folded metal tray in the corner. When the membrane fails, water sits in the bed under the tiles, keeps the grout permanently dark, and finds its way out through the slab, the wall frame or the ceiling below. Efflorescence (a white crust on the grout), lifting tiles and a musty smell are the giveaways.
Regrout, seal or strip it out?
Regrouting and resealing is cheap and worth doing if the flood test passed and the walls are the problem. The "no tile removal" treatments (epoxy grout and a penetrating sealer over the whole recess) can buy a few years on a marginal shower, with the caveat that they are a seal over a failed membrane, not a new one. The proper fix is to strip the tiles, install a new membrane to AS 3740 and retile. In NSW, waterproofing is its own licence class with NSW Fair Trading, and a shower strip-out is well past the value where a contractor licence is required, so use a licensed waterproofer and get the certificate. A plumber is not the trade for the membrane. On a strip-out my job is the rough-in (new breech and spindles or a mixer, new shower arm, the floor waste and trap) and the fit-off at the end, in the order of trades covered in bathroom renovation plumbing and on the renovations page. Done right. Done once.
Shower leaking through the ceiling: what to do today
A shower leaking through ceiling plasterboard has usually been at it for months. Stop using that shower. Put a bucket under the drip. If the plasterboard is bulging with water, poke a small hole in the lowest point with a screwdriver and let it drain into the bucket. If water is anywhere near a downlight or exhaust fan, turn that lighting circuit off at the switchboard until it is dry. The one time this is urgent is when the drip does not stop with the shower off. That is a pipe leak, it belongs under leaks and burst pipes, and the right move is to turn the water off at the meter and ring.
Leaking shower cost: who you pay and what moves the price
The price depends on which of the four causes it is. For a shower leak repair on the plumbing side, Sydney 2026 price guides put a leaking tap repair at $92 to $300, plumbers at $92 to $230 an hour (most around $140) and call-out fees at $69 to $170. A spindle and washer service sits at the low end; a breech replaced through the tiles, a mixer cartridge on order, or an after-hours visit push it up, and anything that needs tiles removed is quoted on inspection. Regrouting, sealing treatments and a full strip and re-waterproof are tiler and waterproofer prices, quoted on the size of the recess and what they find underneath.
| Where the water gets in | The sign | Who fixes it | Cost (Sydney 2026 price guides) |
|---|---|---|---|
| Tap spindles, breech or shower arm | Leaks with the taps running, even into a bucket | Plumber | $92 to $300 for a tap repair; a breech through tiles is quoted on inspection |
| Screen seals and silicone | Water on the bathroom floor outside the screen | You, or a glazier | Seals and a tube of silicone |
| Wall grout and tiles | Leaks only when the walls are wet, mouldy grout lines | Tiler | Quoted on inspection |
| Floor membrane or floor waste | Flood test fails, grout never dries, efflorescence | Licensed waterproofer and tiler; plumber for the waste | Quoted on inspection |
| Pipe in the wall or slab | Wet with the shower off, meter ticking over | Plumber | $230 to $920 for a burst pipe repair |
When to call a plumber (and when it is the tiler)
Call a plumber when the bucket test leaks, when the rose drips with the taps off, when the ceiling is wet with the shower off, or when you are planning a strip-out and need the rough-in done before the waterproofer. Call a tiler or a licensed waterproofer when the flood test fails or the grout is the problem, and a glazier when the screen is loose. Unless water is running with the taps off, book business hours and save the emergency rate.
Monarch Civil & Plumbing is based in Austral and covers South West Sydney and the Macarthur region. If you need a plumber in Green Valley, a shower breech replaced in Campbelltown or the rough-in for a bathroom strip-out in Liverpool, the leaks and burst pipes page covers what I do, and 0455 222 292 gets me directly.
Related guides: hidden water leak detection.
Need it sorted? Ring 0455 222 292 any hour or book online. Monarch Civil & Plumbing is a leak detection plumber, no call-out fee, quoted on inspection, same rate day or night.
Emergency in Liverpool or Campbelltown right now?
Ring 0455 222 292 and Paul answers. emergency plumber Liverpool and emergency plumber Campbelltown say what to shut off while he is on the way; everywhere else within about 20 km of Austral the 24/7 emergency plumber page covers it. Same rate day or night, no call-out fee.
Frequently asked
How do I tell if my shower is leaking from the plumbing or the waterproofing?
Isolate them. Plug the floor waste, fill the base a few centimetres deep and leave it for an hour with the taps off: a leak now is the floor membrane or the waste, which is waterproofing. Then run the shower into a bucket so nothing touches the walls or floor: a leak now is plumbing, usually a tap spindle or the breech behind the wall. Wet the walls and screen last to check seals and grout.
Why is my shower leaking through the ceiling downstairs?
Water is getting past the tiles somewhere and running down the wall frame or through the floor to the room below. The usual sources are a tap spindle or breech leaking inside the wall when the shower runs, a failed floor membrane, or a screen seal letting water out onto the bathroom floor. Stop using that shower, drain any bulge in the plasterboard into a bucket, switch off the lighting circuit if a downlight is wet, then do the test.
Can a leaking shower be fixed without removing tiles?
Often, if the cause is plumbing or the screen. Spindles, washers and O-rings come out through the tap flange, screen seals clip on, and silicone can be cut out and redone. Regrouting and the epoxy and sealer treatments can buy a few years on a marginal recess. If the floor membrane has failed, a seal over the top is a delay, not a repair, and the proper fix is to strip, re-waterproof to AS 3740 and retile.
Who fixes a leaking shower, a plumber or a waterproofer?
It depends on where the water gets in. A plumber fixes taps, the breech behind the wall, the shower arm, the floor waste connection and any pipe leaking in the wall or slab. A licensed waterproofer replaces a failed membrane, a tiler does grout and tiles, and a glazier fixes a loose screen. In NSW waterproofing is its own licence class, so unless your plumber also holds that licence, they should not be the one painting your membrane.
How much does it cost to fix a leaking shower?
For the plumbing side, Sydney 2026 price guides put a leaking tap repair at $92 to $300, with plumbers at $92 to $230 an hour and call-out fees of $69 to $170. A breech replaced through the tiles is quoted on inspection. Screen seals and silicone cost very little. Regrouting, sealing treatments and a full strip and re-waterproof are tiler and waterproofer jobs, quoted on the size of the recess and what they find under the tiles.
Is a leaking shower an emergency?
Rarely. If the leak only happens when the shower runs, stop using that shower, put a bucket under the drip and book a plumber or tiler for business hours. It becomes urgent when water keeps coming with the taps off, which means a pressurised pipe is leaking in the wall or slab: turn the water off at the meter and ring straight away. Water near a downlight means switching that circuit off too.
Licensed plumber and drainer based in Austral, 13+ years in the trade, working across Liverpool, Fairfield and the Macarthur region. About Paul