If you're planning a bathroom renovation in Melbourne, waterproofing is the one trade that must be done right the first time. This guide walks through real 2026 pricing from jobs we quote every week — from small ensuites in Fitzroy apartments to full family bathrooms in Toorak and Brighton — so you know what a fair quote looks like before you sign anything.
Typical bathroom waterproofing cost in Melbourne (2026)
For a standard Melbourne bathroom of 4–6 m², expect to pay between $750 and $1,400 for waterproofing to AS 3740:2021, supplied and installed. Larger family bathrooms of 8–12 m² typically land between $1,400 and $2,400, and premium wet-rooms with hobless showers, benches and multiple penetrations can reach $2,800–$3,800.
These numbers include primer, two-coat liquid membrane, bond breakers to all internal corners, waterstops at doorways, and a compliance certificate on completion. They do not include screed-to-fall, tiling or plumbing rough-in.
What drives the price up or down
Size of the wet area is the obvious factor, but three other things move the price more than square metres: the number of penetrations (each floor waste, tap and mixer needs a bond-breaker collar), the shower detail (hobless and curbless showers require deeper falls and a more complex membrane return), and site access.
A ground-floor bathroom in a Carlton terrace with a laneway loadout is cheap. A 14th-floor Southbank apartment with lift bookings and building manager sign-offs adds a real cost we have to pass on.
Should you choose liquid or sheet membrane?
For 95% of Melbourne bathrooms, a two-coat liquid membrane (Ardex WPM 300 or Gripset 2P) is the right answer. It's fast, it's certified to AS 3740, and it detailed cleanly around penetrations. Sheet membranes are reserved for balconies and podiums where UV and foot traffic are in play.
If a quote pushes you toward a single-coat or cement-based waterproofing product in a shower recess, walk away. That does not meet current standards in Victoria.
What a compliant quote should include
A proper Melbourne waterproofing quote itemises the membrane brand and product code, the number of coats, the extent of upturns (usually 150 mm to a floor waste, 1800 mm in a shower recess), and the compliance certificate on handover. If any of those are missing, ask for them in writing before work starts.
Frequently asked
Is waterproofing included in a bathroom renovation quote?+
Sometimes, sometimes not. Ask your builder whether it is a licensed waterproofer, insured for the trade, and whether a compliance certificate is issued in your name.
How long does bathroom waterproofing take?+
One working day for the application, plus 24–48 hours cure before tiling. We schedule around your tiler so you don't lose days on the program.
Do I need council approval?+
No — waterproofing is regulated by the Victorian Building Authority under AS 3740, not council. The compliance certificate is what your insurer and future buyer will ask for.