What's Included in the Price
For a reseal: removal of failed silicone and grout, joint cleaning, and new sealant application. Materials include bathroom-grade silicone ($12–$18 per tube) and cement-based grout such as Davco Sanitized Colorgrout or Ardex FG8, both of which include anti-mould additives. Epoxy grout is an upgrade option that lasts roughly twice as long and does not need periodic sealing.
For a membrane replacement: tile removal, stripping the failed membrane, substrate repair (including timber framing replacement if rotted), new membrane application under AS 3740:2021 Waterproofing of Domestic Wet Areas, pre-tiling inspection, and retiling. Liquid-applied membranes are standard for shower repairs. Two coats minimum, with 24-hour cure between coats. The pre-tiling inspection is a mandatory hold point under the Building Act 1993: a certifier approves the membrane before any tiles go on.
A diagnostic callout fee ($80–$150) applies. Flood testing to confirm membrane failure may be offered separately. Cosmetic repair to ceilings or walls in rooms below is not included and needs a separate trade.
What Affects the Cost
- Leak source. Failed silicone and grout is a surface fix costing a few hundred dollars. A failed membrane is a full strip-out costing several thousand. The two are not interchangeable, and getting the diagnosis right first saves money.
- Duration of the leak. Melbourne's cool climate slows visible damage, meaning leaks often run for months before detection. Longer leaks mean more subfloor damage and higher remediation costs.
- Timber subfloor condition. Many inner-suburb Melbourne homes have timber-framed bathroom floors. Prolonged leaking rots the timber, and replacement adds $1,000–$3,000+ before new waterproofing can go on.
- Grout type. Epoxy regrout ($800–$1,500) outlasts cement-based ($600–$1,200) and resists Melbourne's winter moisture buildup in grout joints.
- Previous repairs. Regrouting or injection sealing that did not fix the problem points to membrane failure. The next step is a full strip-out.
- Shower type. Hobless walk-in showers have more membrane surface area and more junctions than step-up designs. Falls to drain must meet the AS 3740:2021 minimum of 1:80.
- Body corporate. Apartment shower leaks affecting the unit below involve strata disputes over liability and repair scope. Under the Owners Corporations Act, waterproofing within your lot is typically the lot owner's responsibility.
A straightforward reseal of silicone and grout in a shower with intact membrane in a modern Doncaster or Point Cook apartment sits toward $250. A full strip-out in a Northcote or Brunswick Victorian with rotted timber subfloor, membrane replacement, and retiling pushes toward $3,800.
Melbourne-Specific Considerations
Melbourne's housing stock and climate create distinct patterns for how shower leaks present and what they cost to fix.
Victorian and Edwardian homes (Fitzroy, Brunswick, Northcote, Carlton, Richmond). Timber-framed bathroom floors are standard in these properties. When the membrane fails, water penetrates the timber subfloor over time. Melbourne's cold winters mean slower evaporation, so the timber stays saturated longer and rot progresses faster than many homeowners expect. In Brunswick and Northcote, it is common for waterproofers to find joist ends that are soft and crumbling once the shower floor tiles come off. A flood test before committing to the strip-out confirms whether the membrane is the source, saving the cost of unnecessary tile removal if the problem is only grout or silicone.
Cold weather detection. In Brisbane or Sydney, mould and staining appear within weeks when a shower leaks. In Melbourne, the lower humidity and cooler temperatures slow these visible signs. A leak can run through an entire winter and only become obvious in the following spring. If you notice any hint of dampness, a faint musty smell, or slight discolouration near the shower base, investigate promptly rather than waiting for obvious damage. A simple flood test ($100–$200) can confirm or rule out membrane failure.
Apartment stock (Docklands, Southbank, South Yarra, Box Hill). Melbourne's apartment buildings from the 2000s construction boom are now 20+ years old. Original waterproofing membranes in many of these buildings are approaching end of life. Body corporate involvement is common when a shower leak reaches an adjoining unit. Compact apartment bathrooms (3–5m2) are quicker to strip and retile, which keeps costs toward the lower-to-mid range even for membrane replacement.
Injection sealing. Available in Melbourne as a first-attempt fix. It works by injecting a sealing product behind tiles to form a secondary barrier without removing tiles. It can stop leaking caused by minor grout and silicone failures. If the underlying membrane has broken down, injection sealing delays the problem. When it has already been tried and the leak returns, a full strip-out is the next step.
Hiring a Licensed Waterproofer in VIC
Shower leak repairs involving membrane work must be done by a registered waterproofer. In Victoria, check registration through the Victorian Building Authority (VBA). Search the VBA practitioner register to confirm credentials.
A good waterproofer will offer a flood test before recommending a full strip-out, provide a written quote separating diagnostic, waterproofing, and retiling costs, and issue a compliance certificate on completion.
Worth checking:
- Current VBA registration as a domestic builder limited to waterproofing
- Flood test or leak detection offered before committing to a full strip-out
- Compliance certificate issued on completion
- Pre-tiling inspection confirmed if membrane is replaced
- Written scope clarifying whether retiling is included or quoted separately
How We Calculate
Estimates are based on surveyed rates from VBA-registered waterproofers in the Melbourne metropolitan area, adjusted for property age and construction type in VIC. All prices include GST. Figures cover standard residential shower leak repairs. Full bathroom waterproofing and cosmetic repairs to adjacent rooms are excluded.