A couple in Prestons gutted their 1990s ensuite over a long weekend, stacked the old vanity on the driveway, and rang me on the Tuesday to ask when I could come and "do the plumbing bit". The honest answer was: twice, and not yet. Bathroom renovation plumbing isn't one visit. It's a rough-in before the waterproofer and a fit-off after the tiler, with a strict order in between that decides whether the room leaks in five years. I do a lot of these across South West Sydney, from slab homes in Oran Park to timber-floor cottages in Liverpool, so here's how the job actually runs, what moving a toilet involves, and what it costs. We are a renovation plumber, no call-out fee, across Liverpool and Macarthur.
Bathroom plumbing happens in two visits: the rough-in after strip-out (new pipes and drains set out for the fixtures) and the fit-off after tiling (toilet, vanity, taps, shower). Waterproofing by a licensed waterproofer sits between them and must not be disturbed. Moving a toilet or shower means drainage work under the floor, which is licensed work with paperwork.
The short version: two plumber visits, in this order
Strip-out. Plumbing rough-in. Waterproofing. Tiling. Plumbing fit-off. Then the glazier for the screen and the electrician for the last fittings. Every bathroom I've been called to fix after someone else's renovation had gone wrong the same way, with a step skipped or done out of sequence: tiles laid over a membrane that hadn't cured, a floor waste moved after the waterproofing, a vanity fitted before the pipes were pressure tested. The plumber is the first trade in after demolition and one of the last out, and the waterproofer is the one trade you never squeeze.
Bathroom rough-in: what happens after strip-out
The rough-in is everything you won't see once the tiles go on. I cap the old services, pull out tired pipework, and run new hot and cold lines to wherever the new fixtures are going. Mixer bodies get fixed in the wall at the right height and depth for the finished tile. If the vanity is wall-hung, the waste and water come through the wall, so the pipe positions have to match the drawings before the sheeting goes on. The shower gets its drain and puddle flange set for the fall, the toilet gets its waste and water point, and the whole lot is pressure tested before it's covered. A joint that fails a pressure test now costs an hour. The same leak behind tiles costs the bathroom.
This is also the moment to sort things you can't get to later: a tempering valve if there isn't one (bathroom hot water in NSW is limited to 50 degrees; see my guide to tempering valves), isolation valves so the next dripping tap doesn't mean shutting the house down, and a look at the hot water system. If the tank is fifteen years old, replacing it during the renovation is cheaper and tidier than doing it six months later, and I'll usually do the hot water system installation on the same visit as the rough-in.
Waterproofing and plumbing: why I leave before the waterproofer arrives
Once the rough-in is done and the sheeting and screed are in, the waterproofer takes over. In NSW, waterproofing is its own licensed trade, and you want a certificate from a licensed waterproofer for the job, because the certifier, the insurer and the next buyer will all ask for it. The membrane goes over the floor, up the walls to the required heights and down into the puddle flange at the floor waste, and it has to cure before anyone stands on it. My rule is simple: once the membrane is down, no trade touches that floor until the tiler is finished. No drilling for a towel rail, no moving a waste, no "quick" pipe change. If the plumbing has to move after waterproofing, the waterproofer comes back and does that section again. That's cheaper than the alternative: most leaking showers I see are a pierced membrane or a floor waste fiddled with after the certificate was issued, as I've covered in leaking shower repair.
Bathroom fit-off: the second visit
The tiler finishes, the grout cures, and I come back for the fit-off. The toilet suite goes on and gets connected to its waste and water point, the vanity basin and mixer go in, then the shower rose and arm, the bath spout and handles, the floor waste grate and any wall-mounted trims. Every connection is checked under pressure, every drain is filled and watched, and the toilet is flushed more times than seems reasonable. The shower screen is usually the glazier's job after the fit-off, because it's measured off the finished tiles. If you've picked a back-to-wall or wall-hung pan with an in-wall cistern, the fit-off is where the rough-in either pays off or bites, and I've gone into what that costs in my post on toilet installation cost.
Moving a toilet or a shower: what it really involves
Relocating fixtures is where renovation budgets go sideways. Moving a mixer or basin along the same wall is water pipe work and usually straightforward. Moving a toilet or a shower means moving drainage, and drainage runs under the floor with a fall to the sewer, which is a different order of job. In a slab home in Mount Annan that means cutting and jackhammering the slab, laying new pipe at the correct fall, and pouring it back. In an older Liverpool house on timber bearers it's usually easier because I can get underneath, but the joists and the existing drain runs still decide where the pan can go.
Either way it's licensed plumbing and drainage work with paperwork attached. I lodge a Notice of Work with the NSW plumbing regulator before I start, you get a Certificate of Compliance when it's done, and if the drainage layout changed, the sewer service diagram for the property gets updated. All three are set out on the NSW Government plumbing documents page, and they matter when you sell. My advice: keep the toilet where it is unless there's a strong reason. Most of the improvement comes from the vanity and shower layout, not from the pan moving half a metre.
Shower head replacement and the small jobs that aren't a renovation
Not every bathroom job needs a strip-out. A shower head replacement is one of the few things you can legitimately do yourself: unscrew the old rose from the arm, thread tape on the arm, screw the new one on, done. Swapping a mixer cartridge, replacing a basin mixer or changing a toilet suite like for like is plumber work, but it's a single visit with no waterproofing involved, and our toilets, taps and fixtures service covers all of it. The line is the wall and the floor: if either has to be opened, you're into rough-in territory and the membrane question comes up again.
Bathroom renovation plumbing cost in Sydney
The plumbing is a slice of the renovation, and the size of the slice depends on what moves. Sydney 2026 price guides put a plumber's hourly rate at $92 to $230, most around $140, with a call-out of $69 to $170 for small jobs. A full rough-in and fit-off I quote off the plans as a fixed price, because everything that moves the number is known before I start.
| Job | What it involves | Cost |
|---|---|---|
| Shower head replacement | Unscrew, tape, screw on | DIY, or a call-out at $69 to $170 |
| Worn mixer or dripping basin tap | Cartridge, washer or new mixer, one visit | $92 to $300 |
| Like-for-like toilet or vanity swap | Fit-off only, no waterproofing | Quoted on inspection, usually a half day |
| Rough-in and fit-off, fixtures staying put | Two visits, new pipework, pressure test, paperwork | Quoted from the plans |
| Rough-in and fit-off with the toilet or shower relocated | Adds drainage under the floor and slab cutting | Quoted from the plans; the biggest variable |
When to call a plumber
Ring before you strip out, not after. The best renovations I've done started with a twenty-minute site visit while the old bathroom was still in one piece, so I could see where the drains ran and tell the owner what their layout would cost before they fell in love with it. Ring again any time another trade wants to do something to a pipe or a floor waste. If water is coming through the ceiling below a bathroom mid-renovation, ring straight away and turn the water off at the meter. Nothing else in a renovation is an emergency; a fit-off can wait a day and you'll get the business-hours rate.
Monarch Civil & Plumbing covers South West Sydney and the Macarthur region from Austral, and bathroom plumbing is a big part of what I do through our renovations and new builds service, working alongside your builder, tiler and waterproofer or lining them up for you. If you're planning a bathroom and need a plumber in Prestons, Mount Annan or a South West Sydney plumber who'll give you a fixed price off the plans, call 0455 222 292. Done right. Done once.
Related guides: blocked shower drain and leaking shower repair.
Need it sorted? Ring 0455 222 292 any hour or book online. Monarch Civil & Plumbing is a renovation plumber, no call-out fee: rough-in, waterproofing coordination and fit-off, quoted before we start.
Need it fixed in Liverpool, Fairfield or Campbelltown?
A toilet that will not clear has its own page: blocked toilet. For taps, cisterns and fixtures see toilets, taps and fixtures, and the suburb pages plumber Liverpool, plumber Fairfield and plumber Campbelltown say what we see locally. No call-out fee, price before we start.
Frequently asked
What is a bathroom rough-in?
The rough-in is the first plumbing visit in a renovation, done after strip-out and before waterproofing. The plumber caps the old services, runs new hot and cold pipework and drainage to where the new fixtures will sit, fixes the mixer bodies in the wall at the right depth for the tile, sets the floor waste and puddle flange, and pressure tests everything before it gets covered by sheeting, screed and tiles.
What is a bathroom fit-off?
The fit-off is the second plumbing visit, after the tiler has finished and the grout has cured. The plumber installs and connects the toilet suite, vanity basin and mixer, shower rose and arm, bath spout and handles, floor waste grate and any wall-mounted trims, then tests every connection under pressure and every drain with water. The shower screen usually goes in after the fit-off because it's measured off the finished tiles.
Can a plumber do the waterproofing in a bathroom renovation?
In NSW, waterproofing is its own licensed trade with its own contractor licence, so it's done by a licensed waterproofer who issues a certificate for the job. I do the rough-in before the waterproofer arrives and the fit-off after the tiler has finished, and I don't touch the membrane in between. If plumbing has to change after waterproofing, the waterproofer comes back and redoes that section rather than anyone patching it.
How much does it cost to move a toilet in a renovation?
It's quoted from the plans, because it depends on the floor. On a concrete slab the new drain means cutting and jackhammering the slab, laying pipe at the correct fall and pouring it back, which is the biggest single variable in a renovation budget. On a timber floor with access underneath it's usually less. Either way it's licensed drainage work with a Notice of Work, a Certificate of Compliance and an updated sewer service diagram.
Can I replace a shower head myself?
Yes, if it's only the rose on the end of the arm. Unscrew the old head, wrap thread tape on the arm, screw the new one on and check for drips. That's one of the few bathroom jobs that doesn't need a licence. If the arm itself is loose in the wall, the mixer is leaking or you want the outlet moved, that's inside the wall and it's a plumber's job, and it may involve the waterproofing.
How long does the plumbing take in a bathroom renovation?
For a standard bathroom with fixtures staying put, the rough-in is usually a day and the fit-off is usually a day, with waterproofing and tiling in between taking anywhere from a week to a few weeks depending on the trades and the curing times. Moving a toilet or shower adds slab cutting or under-floor drainage work to the rough-in. The order of trades matters more than the number of days.
Licensed plumber and drainer based in Austral, 13+ years in the trade, working across Liverpool, Fairfield and the Macarthur region. About Paul