What waterproofing costs, and why we put the price on screen.
Waterproofing is one of the most estimable trades there is: the price is genuinely the area by the m², by what is being waterproofed, by the membrane system and the coats. So instead of making you wait for an inspection to learn a single number, we put an honest by-the-m² range on the screen first, named to the Standard your job has to meet. Here is roughly where the numbers sit, what moves them, and how we keep our quote something you can actually compare.
An honest by-the-m² range, in under a minute.
Tell us what you are waterproofing, the area, the system and the coats, and see a real supplied-and-installed band named to the Standard. It is a guide range, not a quote: the site inspection pins your exact number, and it never folds the prep, the flood test or the certificate into a round figure.
Price my waterproofing
An honest by-the-m² range in under a minute, supplied and installed, named to the Standard your job has to meet. Every job is quoted exactly after a site inspection, not over the phone.
Your estimate appears here.
Step through the questions on the left. As soon as you answer the last one, we point you to the honest scope and a realistic range for a job your size.
Supplied and installed, by the m², 2026.
| Cheap quote (one coat, no bond breaker, no flood test) | $25 to $40/m² |
| Internal wet areas (bathrooms and laundries to AS 3740) | $35 to $70/m² |
| Balconies and decks (above ground to AS 4654) | $50 to $95/m² |
| Roofs and podiums (exposed and buried membranes to AS 4654) | $60 to $120/m² |
| Basement and tanking (below ground, holding back water pressure) | $85 to $180/m² |
| Remedial leak repair (diagnosis, cut-out and make-good) | $95 to $220/m² |
Six things that decide where your quote lands.
Most of them are named on the page or hidden under the tiles, not in the finished look. All of them decide what you pay, and whether the membrane is still holding water in ten years.
What is being waterproofed, and the Standard
An internal wet area to AS 3740 is the most contained job. A balcony or roof to AS 4654 adds exposure and drainage. Below-ground tanking has to hold back water pressure. Each sits higher per m² than the last, because the Standard asks more of it.
The membrane system and the number of coats
Cementitious, liquid-applied or sheet, and two coats where the Standard needs two, not one. The system is chosen for the exposure and the substrate, and the coat count is the most common place a cheap quote quietly cuts a corner.
The substrate and the strip-out
A sound, primed substrate is cheap to membrane. Grinding, crack repair, or a full strip-out of failed tiles and old membrane is a real cost before any new membrane goes down. It is itemised, never folded into a round number.
The area, by the square metre
Cost is close to linear in area, so the m² is the single biggest number on the quote. A shower recess and a roof are not the same job, which is why we price by the m² after a look, not off a guess.
The detailing complexity
Corners, the hob, the wastes, the penetrations, the upturns and the fall to drain. A fiddly recess or a balcony with a tricky fall costs more per m² than a flat, open floor, because the detailing is where the work and the risk sit.
Testing and certification
The flood test and the compliance certificate are part of doing it to the Standard, not an extra. Doing it right and proving it holds the first time costs a little more than a job that looks done and leaks again.
Every waterproofing quote splits into the same lines.
So the figure you are comparing is tied to an area, a Standard, a membrane system and a coat count you can read, not a single round number with nothing behind it.
- 1 The area, by the square metre. The price broken down by the m² and the area, not one round number for "the waterproofing". A shower recess, a bathroom and a balcony are different jobs, and the quote should show it.
- 2 The Standard it has to meet. AS 3740 inside a wet area, or AS 4654 outside on a balcony, deck or roof, named on the page. The Standard is what sets the coats and the detailing, so naming it is the honest part of the quote.
- 3 The membrane system and product. Cementitious, liquid-applied or sheet, and the actual product named, not "we will seal it". The system is chosen for the exposure and the substrate, and you should see which one you are paying for.
- 4 The number of coats. How many coats, because the most common cheap shortcut is one coat where the Standard needs two. It is invisible the moment the tiles go down, so it belongs on the quote.
- 5 Prep and any strip-out. The substrate prep, and the strip-out of failed tiles or membrane where it is needed, as their own line. Prep is a real cost before any membrane goes down, never folded into a round number.
- 6 The flood test and certificate. The flood test that proves the membrane holds water, and the compliance certificate a licensed waterproofer issues. The test is the difference between it looks done and it is proven.
- 7 The membrane warranty. The 10-year membrane workmanship warranty in writing, alongside the manufacturer system warranty. The cover a cheap operator will not put on paper, because they cannot stand behind a rushed job.
What you get from us
- ✓Named membrane system and coat count
- ✓Built to AS 3740 or AS 4654
- ✓Bond breakers and falls detailed
- ✓Substrate prepped and primed first
- ✓Flood-tested and certified
- ✓Membrane warranty in writing
Cowboy tells
- ✕"We will seal it." No system named
- ✕No Standard named on the quote
- ✕A coat straight over the junctions
- ✕Straight over a dusty or cracked surface
- ✕No flood test, it just looks done
- ✕Cash job, no warranty in writing
A fixed, itemised quote. Named to the Standard.
Every quote lists exactly what you get, line by line, before you commit to anything.
- Measured by the m²The area measured on site and priced by the square metre, never estimated off a guess.
- The Standard namedAS 3740 inside a wet area, or AS 4654 outside, on the page, so you can compare like for like.
- System, coats and prepThe membrane system and product, the number of coats, and any strip-out, each itemised in writing.
- Test, certificate and priceThe flood test and compliance certificate included, then a single price locked before work starts.
Anything outside this scope, hidden rot, a failed structure, extra strip-out once we open it up, is quoted separately, in writing, before it happens.
Fixed price
Locked before work starts
A leak repair, a full wet area or balcony, or a whole building. We will tell you the smaller job if that is the honest answer.
Re-seal or make-good a leak
A leaking shower, a balcony weeping through the grout, or a single junction gone. We diagnose the source, then re-seal or make-good the membrane, often without a full strip-out where the substrate is sound.
Wrong when: the membrane underneath has failed across the whole area.
A full wet area, balcony or deck
A bathroom, ensuite, laundry, balcony or deck waterproofed to AS 3740 or AS 4654 before the tiles go on. The substrate prepped, the junctions detailed, the coats applied, then flood-tested and certified. The job we do most.
Wrong when: a single junction just needs a re-seal.
Roofs, podiums and whole buildings
Exposed and buried membranes on roofs, podium decks, trafficable terraces and planters, to AS 4654, coordinated with the builder or body corporate. Our commercial and strata path.
Wrong when: a single residential wet area or balcony.
Basement and retaining tanking
Below-ground tanking for basements and retaining walls, built to hold back negative water pressure with a cementitious or specialised system, not painted over and hoped for.
Wrong when: an above-ground surface that just sheds water.
What people ask before they book.
How much does waterproofing cost per square metre?
Why is one waterproofing quote half the price of another?
Do you give a fixed price, or an estimate?
Is the cheapest quote ever the right one?
Priced your job? Book the site inspection and we will pin the exact number.
Tell us what you need. We’ll book a walkthrough and send a quote with the work itemised, not just a number.