Wet area waterproofing

Bathroom and wet area waterproofing in Melbourne

We waterproof showers, bathroom floors, ensuites and laundries, either as a standalone job or as part of a bathroom or laundry renovation. The membrane goes on before the tiles, is detailed at every corner, drain and junction, and is left to cure properly before tiling starts.

Talk to us about your wet areaCall (03) 7065 0017

What waterproofing does, and why it can’t be an afterthought

Waterproofing is a membrane applied to the floors and walls of a wet area, underneath the tiles, that stops water getting into the timber, plasterboard and concrete behind them.

Tiles and grout let small amounts of water through, especially as grout ages. Without a sound membrane underneath, that water finds its way into the frame, the subfloor or the room next door. By the time you see swollen skirting, lifting tiles or mould, the damage is usually hidden behind a finished surface.

Because it is covered up within days, waterproofing is one of the few parts of a renovation that you cannot inspect later. We treat it as its own stage in every bathroom and laundry renovation, with time allowed for preparation and curing.

What we can help with

Wet areas we waterproof

  • Shower recesses, with or without a hob
  • Level-entry and hobless showers
  • Main bathroom and ensuite floors
  • Walls and floors around baths, including freestanding baths
  • Laundry floors and the walls behind tubs
  • Powder rooms and separate toilets
  • Shower niches and recessed shelves
  • Re-waterproofing when an old shower is stripped back

Your written quote sets out which surfaces are waterproofed and any strip-out or retiling involved, whether it is a single shower or a full renovation.

Standards

What the building rules require

In Victorian homes, wet-area waterproofing needs to meet the National Construction Code. The code allows this to be done by following Australian Standard AS 3740, Waterproofing of domestic wet areas, or the equivalent wet-area provisions in the ABCB Housing Provisions.

Among other things, those rules set out:

  • Which surfaces must be waterproof

    The floor and walls of the shower area are treated as fully waterproof. Where a shower has no screen, the waterproofed area extends further out from the shower rose, and walls are waterproofed to at least 1800 mm high.

  • Where water-resistant is acceptable

    Some surfaces outside the shower, such as parts of the walls in a bathroom or laundry, need to be water resistant rather than fully waterproof. Which applies depends on the area and the construction.

  • Falls to the drain

    Shower floors must slope towards the waste. The Housing Provisions set the shower floor fall at between 1:80 and 1:50.

This is a plain-English summary, not the full requirements. The detail for your room depends on its layout, the floor construction and the products used.

Terms explained

Waterproofing words you might hear

These come up when your wet area is being planned. Knowing them makes it easier to follow what is being done.

Membrane
The waterproof layer itself. Most domestic wet areas use a liquid-applied membrane that is brushed or rolled on in coats; some use sheet membranes.
Bond breaker
A flexible strip or sealant at the corners and wall-to-floor junctions, so building movement does not tear the membrane.
Puddle flange
A fitting around the floor waste that the membrane is sealed to, so water reaching the drain cannot track down the pipe.
Waterstop
An angle or bar at the edge of a shower or doorway that keeps water in the waterproofed area and stops it running under the floor tiles beyond.
Fall
The gentle slope of a floor towards the drain, usually given as a ratio such as 1:80.
Cure time
How long the membrane needs to dry and set before tiling. It is set by the manufacturer and varies with temperature and humidity.
Our sequence

How we waterproof a wet area

The order matters as much as the product. Each stage has to be finished before the next one covers it.

01

Strip back and assess

Old tiles, bedding and failed membrane are removed so the substrate can be seen. Any damaged sheeting, framing or flooring found at this point is raised with you before work continues.

02

Set falls and prepare surfaces

Floors are screeded to fall towards the waste, surfaces are cleaned and primed, and puddle flanges and waterstops are installed.

03

Detail the junctions

Bond breakers go into internal corners and along wall-to-floor joins, and penetrations for taps and pipes are sealed. Most leaks start at these points.

04

Apply, cure and check

The membrane is applied in the coats and thickness the manufacturer specifies, left to cure, and checked for coverage before tiling begins.

Existing bathrooms

Signs a shower or bathroom may be leaking

These signs do not prove the membrane has failed, but they are worth looking into before the damage spreads. If you are planning to renovate anyway, it is usually the point to strip back and start again. If not, we can look at the affected area and quote to re-waterproof just that part.

  • Grout or silicone that stays dark or stained long after a shower
  • Tiles that sound hollow when tapped, crack or lift
  • Swollen, flaking or discoloured skirting outside the bathroom
  • Mould or a musty smell that keeps coming back
  • Water marks on the ceiling below an upstairs bathroom
  • Damp carpet or timber floor next to the wet area
Questions

Waterproofing questions

What standard applies to bathroom waterproofing in Victoria?

Wet areas in Victorian homes need to meet the National Construction Code. The usual way to do that is to follow Australian Standard AS 3740, Waterproofing of domestic wet areas, or the wet-area provisions in the ABCB Housing Provisions.

Which parts of a bathroom need waterproofing?

The shower floor and walls must be waterproof, with walls in an unscreened shower waterproofed to at least 1800 mm. The rest of the bathroom floor and some walls need waterproof or water-resistant treatment depending on the layout and floor construction.

How long does a waterproofing membrane take to cure?

It depends on the product, the number of coats, and the temperature and humidity. The manufacturer sets the cure time, and tiling should not start until it has passed.

Can a leaking shower be fixed without removing the tiles?

Surface sealers and regrouting can help when the problem is worn grout or silicone. They cannot repair a failed membrane underneath. A lasting fix for membrane failure usually means removing the tiles and re-waterproofing.

Can you waterproof a shower without renovating the whole bathroom?

Yes. We take on standalone waterproofing, such as re-waterproofing a shower recess or a laundry floor. The tiles in that area come up so the membrane can be replaced, and the area is then retiled. Your quote sets out the strip-out, waterproofing and tiling involved.

Do laundries need waterproofing?

Yes. A laundry is a wet area under the building code, so the floor and the walls around tubs and taps need waterproof or water-resistant treatment, depending on the construction.

Floor and wall tiling

The finish that goes over the membrane once it has cured.

Explore tiling

We work across Melbourne and surrounding areas of Victoria. See the areas we service

Waterproofing is one part of a wet-area renovation. View all renovation services

Planning a wet area?

Get the waterproofing right from the start

Tell us about the bathroom, ensuite or laundry and what you have noticed so far. We will get back to you to talk through the options.

Or call (03) 7065 0017 or email info@pacificedgehomes.com.au.

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