Bathroom waterproofing in Pakenham & Cardinia.

Pakenham’s first big estate wave — Cardinia Lakes, Lakeside and Heritage Springs — went up in the early 2000s. Those original wet areas are now 15 to 20-plus years old, and early-2000s waterproofing membranes have reached the end of their service life. They crack at the floor-to-wall junction, fail behind the shower hob, and lose adhesion at penetrations. Once the membrane fails, water tracks into the screed, the substrate, the wall framing and sometimes the adjoining room — and the damage is usually well advanced before you see a stain. That is exactly why re-waterproofing is the most common renovation trigger across the estate stock.

Signs your waterproofing has failed.

• Lifting, drumming or hollow-sounding floor tiles in the shower zone.
• Swollen skirting, paint blistering or a musty smell in the adjoining room or hallway.
• Cracked or missing grout and perished silicone at the floor-to-wall junction.
• Efflorescence (white salt residue) creeping out from under tiles.
• A damp patch or stain on the ceiling below an upstairs bathroom.

How we remediate — properly.

1. Inspect & isolate: find the source, moisture-test the substrate, and work out whether the failure is contained to the shower or widespread.
2. Remove tiles & bed: a new membrane cannot be applied over existing tiles, so the affected area is stripped back to substrate.
3. Dry & repair: dry the cavity, replace any rotted or water-damaged substrate, and re-set the floor falls.
4. Re-waterproof to AS 3740: correct falls, a fresh membrane to the right heights, sealed junctions and penetrations — with proper cure time.
5. Re-tile & refit: tile, grout, re-silicone and refit the screen so the bathroom is back in service and sealed for the long term.

2026 cost guide & a worked example.

Waterproofing remediation with re-tiling typically runs $6,000–$15,000, driven mostly by how much tiling and substrate has to come out to reach the failed membrane. As a worked example, a leaking Cardinia Lakes shower recess — remove the shower-zone tiles and bed, dry and repair the substrate, re-waterproof to AS 3740 and re-tile the recess and floor — comes in around $9,500: roughly $2,800 tile removal and substrate repair, $2,200 waterproofing and screed, $3,500 tiling and materials and $1,000 for the plumbing and screen refit. If the membrane has failed widely we will tell you honestly that a full bathroom renovation is the better spend.

Compliance.

• AS 3740 — waterproofing of domestic wet areas, every time.
• VBA-registered building practitioner with a VBA plumbing licence and Compliance Certificate.
• NCC Volume 2 for any structural make-good.

We re-waterproof bathrooms across Lakeside and the wider Cardinia Shire. Planning a full redo instead of a repair? See the full bathroom renovation page.