The short answer
Take photos, work out who did the waterproofing and put the problem in writing before anyone rips anything out. Check your warranty period, because who pays often depends on when the work was finished and who did it.
General information only. Whether a leak counts as a major defect depends on the facts, so ask your regulator. Rules on waterproofing and certificates vary by state and council.
Confidence: likely. These facts come from official pages that we found by search and did not read in full. Check the linked source before you rely on a figure.
First hour
- Stop using the shower if water is getting into walls or ceilings.
- Photograph stains, drips and any damage with dates.
- Note when it started and what changed recently.
- Find your paperwork: the contract, the waterproofing certificate and the tradie's details.
Who to call
Start with the builder, waterproofer or tiler who did the work and tell them in writing. A licensed plumber can find where the water is coming from. Ask for the findings in writing, with photos.
Check the certificate
The Australian Building Codes Board says wet area waterproofing is covered by the National Construction Code and AS 3740. Councils usually want a certificate signed by the builder or a licensed contractor. If you do not have one, ask for it.
Who pays
If the work is still inside its warranty, the person who did it may have to fix it. NSW statutory warranties run six years for major defects and two years for other defects, and the ACT and Tasmania have their own periods. Use our guide on defects and warranty periods, then ask your regulator whether your leak counts as major.
Get a second opinion
Forum threads show homeowners paying for a leak investigation, then being quoted a large destructive repair. Before you agree to rip out a bathroom, get a second written opinion from another licensed tradie.
Common questions
Who is responsible for a leaking shower?
Usually the builder or contractor who did the work, if it is still inside the warranty. Check your contract and your state's warranty period.
Should I get a second opinion on a leak repair?
Yes, especially before an expensive repair that involves removing tiles or walls.
Sources
- ABCB: waterproofing in houses, checked 12 November 2026
- Building Commission NSW: how we deal with building complaints, checked 12 November 2026
- Consumer Affairs Victoria: building disputes, defects and delays, checked 12 November 2026