How much does bathroom waterproofing cost in Melbourne?
About $650–$990 to waterproof a standard bathroom during a renovation in Melbourne in 2026, and about $350–$750 for an ensuite or laundry. The work must meet AS 3740 and the National Construction Code, and where there is a floor waste the floor needs a continuous fall of 1:80 to 1:50 to it.
Price guide
| Job | Melbourne 2026 guide |
|---|---|
| Standard bathroom, renovation (prep, membrane, inspection-ready) | $650–$990 |
| Standard bathroom, new build | $500–$800 |
| Ensuite or small bathroom (shower recess and wet floor) | $350–$750 |
| Laundry or other wet area | $350–$750 |
Wet room and walk-in shower floors
A wet room or hobless walk-in shower has no step or screen base to hold water back, so the floor itself does the work. That means:
- Falls: where a floor waste is installed, the NCC 2022 Housing Provisions call for a continuous fall of at least 1:80 and no more than 1:50 to the waste.
- Drain choice: a linear (strip) drain lets you use larger floor tiles because the floor only falls one way.
- Membrane coverage: expect the whole floor and the shower walls to be membraned, with bond-breakers and upturns at every wall junction.
- Older houses: timber floors often need re-sheeting or a screed to create the fall, which adds to the cost.
Why it is worth paying for
Failed waterproofing is one of the most common building defects, and it usually only shows up after tiles are down, as damp skirting, swelling floors or mould next door. Ask for the membrane product name, the AS 3740 compliance statement and photos of the membrane before tiling.
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Open the bathroom tile visualiserQuestions people ask
How much does bathroom waterproofing cost in Melbourne?
About $650–$990 for a standard bathroom renovation and about $350–$750 for an ensuite or laundry in 2026.
What standard covers bathroom waterproofing in Australia?
AS 3740 (Waterproofing of domestic wet areas), referenced by the National Construction Code.
What fall does a shower floor need?
Where there is a floor waste, the NCC 2022 Housing Provisions require a continuous fall of at least 1:80 and no more than 1:50 to the waste.
Does a wet room cost more to waterproof?
Usually yes. With no hob or step, the whole floor has to be graded and membraned to the waste, and timber floors may need re-sheeting or screeding first.
Do I need to redo waterproofing when retiling a shower?
In most cases, yes. Lifting old tiles damages the membrane underneath, and older membranes may not meet the current standard.
Related guides
Sources
- VDW – waterproofing cost Melbourne 2026
- Cook Kelly – waterproofing falls in wet areas (AS 3740, NCC)
- ABCB – National Construction Code
These are guide prices for planning, not a quote. Quantities and costs depend on the room, the products you choose and what is found once work starts. Confirm waterproofing, falls and permits against the National Construction Code, Australian Standards and your council with a licensed tradesperson or building practitioner before you buy or build.