Bathroom tiling in Melbourne: waterproofing first, tiles second

Regrout, retile or renovate?

Cracked grout or a few loose tiles can sometimes be fixed on their own. But water stains on the other side of the wall, tiles that sound hollow when tapped, swollen skirting boards or mould that keeps coming back usually mean water is getting behind the tiles. New grout won't fix that: the waterproofing underneath has to be found and repaired.

The Building and Plumbing Commission calls water getting into buildings one of the most common and costly building defects in Victoria, and notes it often develops gradually, out of sight. If you're seeing signs of it, ask for an inspection before you ask for a tiling price.

Waterproofing comes first

Waterproofing is a class of building work of its own in Victoria: the application, installation and repair of waterproofing membranes or systems. In a bathroom it sits under the tiles in the shower, across the floor and up the walls, and once the tiles are on, you can't see it.

So ask about it directly: who's doing the waterproofing (the tiler or a separate waterproofer), what product they'll use, which areas it covers, how long it needs before tiling and before the first shower, and what record you'll get of it, such as photos before the tiles go on.

Which trades and registrations a bathroom needs

Tiling on its own doesn't need a registered builder in Victoria, whatever it costs. But a bathroom job rarely stays as only tiling. Waterproofing, moving taps or the shower, new lights or an exhaust fan, and new wall sheeting are all different trades.

If one contract covers more than one of these trades and is worth more than $10,000, it has to be done by a builder registered with the Building and Plumbing Commission, under a major domestic building contract. The deposit can't be more than 10% for a contract under $20,000, or 5% for $20,000 or more, and for eligible contracts over $20,000 signed from 1 July 2026, the builder must take out Home Warranty insurance.

• Plumbing: a plumber registered or licensed with the BPC, and a compliance certificate from a licensed plumber for work worth more than $750
• Lights, power points, heated towel rails and exhaust fans: a licensed electrician, with a Certificate of Electrical Safety
• Waterproofing, tiling and sheeting: the tiler, a waterproofer or a builder, as agreed in the contract

Asbestos in older bathrooms

If the home was built or renovated before 1990, the wall and ceiling sheeting in wet areas, the backing behind wall tiles and old vinyl floor tiles may contain asbestos. Don't cut, grind, sand or drill them with high-speed power tools.

Have a sample tested before demolition, or treat the material as asbestos: see asbestos in older homes. Removal is best done by a licensed asbestos removalist, and waste may only go to a site licensed by EPA Victoria to accept it.

Choosing tiles and finishes

Bathroom floors get wet, so ask about each floor tile's slip resistance as well as its look. The floor also needs to fall towards the waste so water drains away rather than pooling; ask how the tiler will form the falls, especially in a shower without a step.

Ask what grout they recommend for the shower, and where they'll use flexible silicone instead of grout: usually in internal corners and where walls meet the floor or bath. Keep a few spare tiles for future repairs.

What a bathroom tiling quote should list

Ask for these as separate lines. A low price that leaves out preparation or waterproofing usually isn't the cheaper one.

• Demolition, and disposal of old tiles and fixtures
• Asbestos testing, and removal if needed
• Repairing or replacing wall sheeting and the floor
• Waterproofing: product, areas covered and who does it
• Floor falls and screed
• Tiles, adhesive, grout, trims and silicone, and who supplies them
• Plumbing and electrical work, or a note that it's quoted separately
• How long you'll be without the bathroom, and clean-up

How long before you can shower

Membranes, adhesive, grout and silicone each need time to cure, and the right time depends on the products. Ask for the full timeline before work starts, including when the shower can be used, so you can plan around it.

Example brief

“Shower recess retile in a 1980s house in Box Hill. Water stain on the hallway side of the shower wall, and two tiles sound hollow. About 1 m × 1.2 m with a hob. Please advise on inspecting the waterproofing and asbestos testing first, then quote stripping, waterproofing, tiling, grout and silicone. I'd like to keep the existing taps where they are.”

Before booking a bathroom tiler

• The cause found before the tiles are priced
• Who waterproofs, with what, and a record of it
• A registered builder if one contract covers several trades over $10,000
• Asbestos tested in a pre-1990 home
• Slip-resistant floor tiles and proper falls
• Curing times and when you can shower

Ready to describe it? Start a job request or browse tiling work. Tiling a kitchen? See kitchen tiling. Paying in stages? See paying a tradie. Availability depends on real postings, and registration must be enabled to submit.