Waterproofing

The layer everything else in a bathroom depends on. Done to the standard, photographed at every stage, and certified.

QBCC Licence 15535375 • $10m public liability • Master Builders member • 7-year workmanship warranty • 4.9★ on Google • 3,000+ jobs across Brisbane and the Gold Coast

Why waterproofing is the part that matters

Waterproofing is the one part of a bathroom you never see once it is finished, and the one part that costs the most to put right when it fails. A failed membrane does not stay in the bathroom. It goes into the wall frame, the floor, and the room next door.

It is also the step most likely to be rushed, because nobody is looking. We photograph every stage of ours, and those photos go to you.

The standard we work to

AS 3740:2021, the Australian standard for waterproofing of domestic wet areas.
NCC Housing Provisions 10.2.1(b), which makes AS 3740 mandatory. This is the National Construction Code edition in force in Queensland until 30 April 2027.
QDC MP 4.5, the Queensland Development Code provision covering grading and floor wastes.

Every wet area we waterproof gets a certificate and a photo record of the primer, each membrane coat and the finished substrate before tiling. You keep both. If you ever sell the house, or ever need to make a claim, that record is what proves it was done right.

What we waterproof

Bathrooms

Shower areas, floors, walls and hobs, as part of a full renovation or a shower makeover.

See bathroom renovations

Laundries

Floors and splash zones, with the floor waste graded properly.

See laundry renovations

Balconies and external wet areas

Where water has to be kept out of the structure below.

Ask about your job

What it costs

Waterproofing is normally part of a larger job rather than a standalone one, so it sits inside your renovation quote as its own line rather than carrying a published price of its own. Two things are worth knowing:

Upper-storey bathrooms. We offer an extra layer of waterproofing above the bedding on upper-storey bathrooms, and on any bathroom where a past failure is suspected. It is optional and we ask on every quote rather than adding it quietly.
Toilet rooms. A separate toilet room only needs waterproofing where there is a loose spray fitting on the wall. If the spray is built into the pan or seat, it does not.

Signs your waterproofing has failed

Paint bubbling or plaster staining on the other side of a shower wall
A musty smell in the room next to the bathroom
Loose or drummy tiles in the shower base
Silicone that keeps going black no matter how often it is redone
Swollen skirting or flooring near the bathroom door

If you have any of these, get it looked at before you re-tile. Tiling over a failed membrane just buries the problem.

Common questions

Can you just re-waterproof my shower without a full renovation?

Yes, that is what a complete shower makeover is. We strip back to the substrate, re-waterproof and re-tile the shower without touching the rest of the room. It starts from $11,500.

How long does waterproofing take to cure?

Each coat needs drying time, and the whole system usually needs a couple of days before tiling. Rushing it is the most common cause of failure, so we do not.

Do I get a certificate?

Yes. A waterproofing certificate plus a photo record of every stage, handed over with the rest of your compliance paperwork.

Is waterproofing covered by your warranty?

Yes. Waterproofing failure that lets water penetrate is covered as a structural defect for 7 years under our workmanship warranty, on top of your statutory warranties.

My builder says my bathroom does not need waterproofing. Is that right?

Very unlikely. Wet areas in a home are covered by AS 3740 through the National Construction Code. If someone is telling you a shower does not need it, get a second opinion.