Understanding shower waterproofing in Perth
A shower recess is waterproofed once the floor has been shaped and before any tile goes down. The membrane covers the floor and runs up the walls. Waterstops keep water inside the recess, the floor falls to the waste, and a flood test checks the work while problems are still easy to fix.
Helping a shower stay dry
Picture the finished room. Water runs straight to the waste, nothing pools in the corners, the hallway floor stays dry and tiles are less likely to lift. All of that is decided before the tiler arrives: by how the base is shaped, how the membrane is laid at every joint and whether the recess is tested.
Falls, waterstops and membrane coats
The concrete or screed base is shaped so water drains to the waste instead of sitting in low spots. Waterstops at the shower edge and doorway stop water creeping under tiles into the next room. The membrane goes on in coats over a clean, dry surface, with extra care at corners and around the waste.
Flood testing before tiles go down
Once the membrane has cured, the recess is plugged, filled with water and left to stand. Then the area underneath and around it is checked for moisture. If it passes, tiling can begin. If it fails, the weak spot is found and repaired while it is still exposed, then the recess is tested again.
Why the membrane standard matters to your decision
Under the NCC housing provisions, any membrane used as a waterproof material in a wet area must comply with AS/NZS 4858. A shower can meet the code through a Deemed-to-Satisfy Solution, a Performance Solution or both, and AS 3740 is the published guidance for shower areas. Ask which membrane and approach your shower will get.
How long a shower membrane should last
A membrane sits under the tiles, out of reach of feet and cleaning products, so how long it lasts depends far more on how it was installed than on its age. A sound base, correct falls, full coverage and a passed flood test give it the best start. Keeping grout and silicone in good repair helps protect it.
Contract points for a full shower rebuild
If the rebuild comes under the Home Building Contracts Act, the contractor must give you the Notice for the Home Owner before you sign, and the deposit is capped at 6.5%. Any changes to the waste or water supply should be done by licensed professionals.
Your next step: new shower or rebuild?
Note whether the shower is going into a new bathroom or replacing an old recess, roughly how big it is, whether it will have a hob or level entry, and which suburb it is in. If the old tiles and membrane have already been stripped out, say so, because that changes what still needs doing.
What shower waterproofing can cover
New shower recess
Waterproofing a shower in a new home or extension, applied to a fresh base once the falls are formed.
Shower rebuild
Stripping an old recess back to the base, then new falls, waterstops and membrane before retiling.
Hobless or walk-in shower
Level-entry showers that rely on accurate falls and well-placed waterstops to keep water inside the wet zone.