Brett Field
Waterproofing a bathroom usually costs $500 to $1,800, or about $35 to $85 per square metre, depending on the size of the room. A large or complex bathroom can run to $4,000 or more.
Below are the published prices, what changes them, who can do the work in Queensland, and what the building code says must be waterproof. These are market prices from cost guides, checked on 4 October 2026. They are not a quote from us.
How much does bathroom waterproofing cost?
Most bathrooms land between $500 and $1,800. Here is what the main cost guides say.
| What | Typical cost | Source |
|---|---|---|
| Per square metre | $50-$85 | Yellow Pages (2025) |
| Per square metre | $35-$60, about $40 on average | Oneflare (2022) |
| Small bathroom (up to 5 m2) | $550-$900 | Yellow Pages (2025) |
| Medium bathroom (6-10 m2) | $900-$1,800 | Yellow Pages (2025) |
| Large bathroom | $2,000-$4,500 | Yellow Pages (2025) |
| Average bathroom | $500-$1,000, up to $4,000 | Oneflare (2022) |
| Bathroom waterproofing, Gold Coast | $685-$3,425, typically $1,375 | What's The Damage (2026) |
What's The Damage sets its city prices with pricing modifiers on national data, so the Gold Coast line is not a local survey. We could not find one.
How much does it cost to waterproof just a shower?
Yellow Pages puts shower-only waterproofing at $500 to $1,200, and fixing a leak or restoring failed waterproofing at $800 to $1,200.
Know what you are paying for. What's The Damage notes that a cosmetic update, which tiles or paints over the old bathroom, does not redo the waterproofing. A full renovation strips it out and does it again to the AS 3740 standard.
What does waterproofing cost in a full bathroom renovation?
About 8% of the budget. In What's The Damage's breakdown of a typical $27,000 mid-range bathroom, waterproofing comes to about $2,200.
That is a small share for the part that does the most damage when it fails. Our bathroom renovation cost guide shows what every other part of the job costs.
What makes waterproofing cost more?
- Size. The cost guides price it by the square metre, so a bigger room costs more.
- Timber floors. On a timber or particleboard floor, the building code says the whole bathroom floor must be waterproof, not only the shower. On a concrete floor, the area outside the shower only needs to be water resistant.
- The whole room or just the shower. A full bathroom costs more than a shower on its own.
Who can do waterproofing in Queensland?
In Queensland, building work over $3,300 must be done by someone with a QBCC licence for that type of work. The QBCC has a separate waterproofing licence class, which covers work to "apply, install and repair waterproofing, including surface preparation".
Waterproofing is not on the QBCC's list of work that needs a licence at any value, the way plumbing and drainage are. But a full bathroom renovation costs far more than $3,300, so the job must be run by a licensed contractor, and the plumbing must be done by a licensed plumber whatever it costs.
Before you sign, ask who will do the waterproofing and which licence they hold. Where the job has a building approval, a Queensland Form 43 lets a QBCC licensee certify one part of the work, and the form gives "wet area sealing to showers" as an example. This is a summary, not legal advice.
What does the building code say must be waterproof?
Queensland still uses the National Construction Code 2022, and will until 1 May 2027. Its Part 10.2 wet area rules set the minimum for a house bathroom.
| Area | NCC 2022 rule |
|---|---|
| Shower floor | Waterproof, including any hob or step-down |
| Shower walls | Waterproof to at least 1800 mm above the floor substrate |
| Joins inside the shower | Wall joins waterproof for 40 mm either side. Wall/floor joins and pipe holes waterproof |
| Floor outside the shower, concrete or fibre-cement | Water resistant |
| Floor outside the shower, timber or particleboard | Waterproof |
| Wall beside a bath with no shower | Water resistant to at least 150 mm above the bath, where the bath is within 75 mm of the wall |
| Open shower with no screen or hob | A waterstop at least 1500 mm out from the shower rose |
The code defines waterproof as a material that does not let water through. Water resistant only means it slows water down and is not damaged by it. That is why the shower gets the most work.
Why does waterproofing matter so much?
Because failed waterproofing is expensive to fix. The QBCC says each bathroom claim finalised under the Queensland Home Warranty Scheme in 2024-25 averaged almost $25,000 in repair costs.
In a February 2026 article for builders, the QBCC lists why waterproofing fails: the wrong product, rushed work, products used outside the maker's instructions, and work that is not inspected or tested before the job is left. It also expects licensees to keep "records, photos and test certificates" of the work.
Work that lets water into a building counts as a structural defect under the QBCC's rules, and home warranty cover for structural defects lasts 6 years and 6 months.
Curing time matters too. Our guide to how long a bathroom renovation takes shows why the membrane sets the pace of the whole job.
What should a waterproofing quote include?
Check that the quote, or the bathroom quote it sits in, says:
- which areas get waterproofed: the shower floor and walls, the whole floor, and around the bath
- the membrane product being used
- whether the shower is flood tested
- who does the work, and their QBCC licence
- that you get photos and any certificate when it is done
Waterproofing is part of a full bathroom renovation with us, and Brett books and runs the trades for you. More on how we work is on our bathroom renovations page.
Where do these prices come from?
Checked on 4 October 2026: Yellow Pages (bathroom waterproofing cost, 2025), Oneflare (waterproofing cost guide, 2022), What's The Damage (national and Gold Coast bathroom pages, 2026). Rules from the QBCC (licence pages, defect and home warranty pages, and its February 2026 waterproofing notice), the Queensland Government (Form 43 and Business Queensland), and the Australian Building Codes Board (NCC 2022 Part 10.2). We will check the prices again every three months.
See our bathroom renovations work, or check what your job will cost.
