What's Included
A shower leak repair covers diagnosing the source of the leak, repairing or replacing the failed component, and reinstating the surface finish. The scope varies significantly depending on what has failed.
For a reseal (grout and silicone replacement), the work includes removing old silicone with a razor tool, raking out deteriorated grout with an oscillating multi-tool, cleaning joints, and applying new sealant. Materials for a reseal are modest: a tube of bathroom-grade silicone such as Selleys Wet Area Silicone ($12–$18 per 300ml cartridge) or SikaSeal Kitchen and Bathroom (~$14 per 300ml), plus grout. Professional regrouting of a standard shower runs $600–$1,500 depending on size and grout type.
For a membrane replacement, the work involves removing tiles, stripping the failed membrane, repairing any substrate damage, applying a new membrane compliant with AS 3740:2021 Waterproofing of Domestic Wet Areas, passing a pre-tiling inspection, and retiling. Membrane products include liquid-applied systems such as Crommelin Shower Waterproofing Membrane (~$80 for 4L, enough for a standard shower) or Ardex WPM 300 and Davco K10 Plus (~$100 for 4L, ~$245 for 20L). A full strip-out and re-waterproof with retiling is a 3-to-5-day job.
Injection sealing sits between these two options. Products are injected behind tiles to form a secondary barrier without removing the tiles. Companies such as Megasealed offer this as a same-day service. It can stop leaking caused by minor grout and silicone failures, but it does not replace a failed membrane. If the underlying membrane has broken down, injection sealing delays the problem rather than solving it.
A callout or diagnostic fee ($80–$150) applies to most jobs. Flood testing the shower base to confirm whether the membrane has failed may be offered as a separate line item before committing to a full strip-out.
Repair Types Compared
| Repair Type | Typical Cost | Timeline | What It Fixes | Durability |
|---|---|---|---|---|
| Silicone reseal | $150–$400 | Half a day | Failed silicone at junctions, shower screen, and base | 5–8 years before silicone needs replacing again |
| Regrout (cement-based) | $600–$1,200 | 1 day | Cracked, stained, or mouldy grout joints | 8–12 years with regular cleaning and sealing |
| Regrout (epoxy) | $800–$1,500 | 1 day | Same as above, with superior mould resistance | 15+ years, no sealing required |
| Injection sealing | $700–$1,500 | 3–4 hours | Minor grout and silicone failures, no tile removal | Months to a few years. Not a permanent fix for membrane failure. |
| Partial membrane repair | $2,000–$4,000 | 2–3 days | Localised membrane failure (shower floor only) | 15–20 years if installed to AS 3740 |
| Full strip-out and re-waterproof | $4,000–$6,500+ | 3–5 days | Complete membrane failure, includes retiling | 15–20 years. The permanent fix. |
Cement-based grouts such as Davco Sanitized Colorgrout (~$26 for 1.5kg) and Ardex FG8 (~$26 for 5kg) include anti-mould additives but remain porous and need periodic sealing. Epoxy grout costs more upfront but is non-porous, stain-resistant, and does not require sealing. For shower floors especially, epoxy is the better long-term choice.
What Affects the Cost
- Surface problem vs membrane failure. Cracked grout or peeling silicone is a surface fix costing a few hundred dollars. A failed membrane underneath the tiles requires a full strip-out and replacement costing several thousand. Getting the diagnosis right before committing is critical.
- Shower size and type. Larger showers with more tiles cost more to strip and retile. Hobless walk-in showers have more membrane area and more complex drainage falls than step-up (hob) designs. Under AS 3740:2021, the minimum fall to waste in shower areas is 1:80.
- Grout type. Epoxy grout ($800–$1,500 for a full regrout) costs more than cement-based ($600–$1,200) but lasts roughly twice as long and resists mould without sealing.
- Tile condition. If tiles can be saved during a partial repair, costs stay lower. If tiles are cracked, hollow-sounding, or discontinued and cannot be matched, full retiling is needed.
- Subfloor damage. If the leak has persisted for months or years, timber framing underneath may be rotted. This must be repaired before new waterproofing goes on. Timber remediation can add $1,000–$3,000+ depending on the extent of damage.
- Previous repair attempts. Showers that have been regrouted or injection-sealed before but still leak usually indicate membrane failure. The money spent on those repairs is gone.
- Building type. Apartments add strata complications. If the leak is affecting the unit below, there may be insurance and body corporate considerations. Under most state strata legislation, waterproofing within your lot boundary is the lot owner's responsibility.
A silicone and grout reseal on a standard shower hob where the membrane is intact sits toward $250. A full strip-out of a hobless shower with confirmed membrane failure, rotted timber subfloor requiring framing replacement, and full retiling pushes toward $4,000.
How to Tell What Has Failed
Not every shower leak needs a full strip-out. The symptoms point to the source.
- Silicone failure: Water seeps at the junction between the shower screen and tiles, or between the shower base and wall tiles. The silicone looks discoloured, has pulled away from the surface, or has black mould growing through it. Dries between showers. Fix: reseal.
- Grout failure: Water tracks through cracked or missing grout joints. Grout appears chalky, powdery, or has gaps. Dampness shows on the other side of the shower wall. Fix: regrout.
- Membrane failure: Persistent dampness that does not dry between showers. Water stains on the ceiling below. A musty smell that lingers. Soft or spongy floor near the shower base. Fix: full strip-out and re-waterproof.
A flood test confirms membrane condition. Block the drain, fill the shower base with 10–20mm of water, and leave it for 24 hours. If dampness appears outside the shower area, the membrane has failed. A good waterproofer will offer this test before recommending a full strip-out.
City and Regional Price Comparison
Shower leak repair pricing varies across Australia based on labour rates, construction methods, and local housing stock.
City-level differences: Sydney (NSW) is the baseline. Melbourne tracks close to Sydney. Brisbane often sits slightly below due to concrete slab construction being standard, which limits subfloor damage from leaks. Perth and Adelaide run 10 to 15 percent above Sydney rates, reflecting smaller trade pools, higher material logistics costs, and longer booking lead times for specialist waterproofers.
Property-level differences: Within any city, the main variable is the age and construction of the property. Older homes with timber-framed bathroom floors face higher repair costs because leaked water damages the subfloor structure over time. Concrete slab homes limit the damage scope because the slab itself does not deteriorate from water exposure, though the leak may travel sideways to adjacent rooms. Inner-city areas with older housing stock (Sydney's terraces, Melbourne's Victorians, Adelaide's character homes) consistently produce more complex repairs than newer outer suburbs. Properties built during construction booms (2003–2012 in Perth, 1990s–2000s apartment stock in Sydney and Melbourne) are now reaching the age where original waterproofing is approaching end of life.
How We Calculate
Estimates are based on surveyed rates from licensed waterproofers and plumbers across Australian capital cities, adjusted for regional labour markets and property age. All prices include GST. Figures cover standard residential shower leak repairs. Commercial properties and full bathroom waterproofing replacements are not included.