Warranties, the waterproofing certificate, and caring for a new bathroom
The four warranty layers explained. What the AS 3740 certificate of compliance is for. Plus the simple aftercare routine that keeps a new bathroom right for years.
Short answer: A warranty is only as good as the paperwork behind it. Leave handover day with the four warranty layers in writing, plus the AS 3740 certificate. Then a short aftercare routine keeps it all valid.
The four warranty layers
Most disputes come from confusing one layer for another. They stack, and each covers something different. Know which is which and a vague brochure claim turns into a clear answer about who fixes what.
6 yr
NSW statutory warranty for major defects on residential building work
NSW Home Building Act
2 yr
NSW statutory warranty for other defects
NSW Home Building Act
7 yr
Bathline workmanship warranty, in writing, on every renovation
Standard terms
Statutory cover is the floor set by law. A real builder adds a workmanship warranty on top, in writing.
What good handover paperwork looks like
The difference between a bathroom you can stand behind and one you cannot is a folder. On handover day a good builder gives you the certificate of compliance, the warranty terms, the product manuals and the selections schedule. A builder who hands you keys and a handshake has left you nothing to make a claim with.
No paperwork
A full handover pack
A handshake and a verbal "she will be right".
A written workmanship warranty with a start date and a term.
No certificate, so you cannot prove the membrane meets standard.
The signed AS 3740 certificate of compliance, filed for you.
No record of what was installed.
Product manuals and the named selections schedule for every fixture.
No one named to call when something moves.
A clear callback contact and how the warranty is claimed.
Aftercare that keeps the warranty valid
A new bathroom asks very little of you, but the little it asks matters. The jobs below take minutes and they are the difference between a small fix under warranty and an expensive repair outside it.
The simple aftercare routine
Renew silicone joints when they discolour or lift. It is the first seal to age.
Reseal natural stone on the supplier's schedule so it stays water resistant.
Run the exhaust fan or open a window after every shower to keep steam moving.
Report any movement, damp patch or grout crack early, while it is still small.
✓Good sign
Your builder gives you a folder on handover day with the certificate of compliance, the written warranty, product manuals and the selections schedule. That folder is what turns a promise into something you can actually claim on.
Common questions
What does a bathroom renovation warranty actually cover?
There are four layers, and a brochure that says "5-year warranty" rarely tells you which one it means. The statutory warranty is set by the NSW Home Building Act. The workmanship warranty is what the builder offers on their labour. The manufacturer warranty covers the products, like the tapware and the membrane. Home Building Compensation cover is the insurance that steps in if the builder cannot. Get all four in writing and you know exactly who is liable for what.
What is the waterproofing certificate of compliance and why do I need it?
It is a signed document from the licensed waterproofer confirming the membrane meets AS 3740. It is your insurance, your strata record if you are in an apartment, and your defence if a leak shows up years later. Without it you cannot prove the waterproofing was done to standard, which makes a future claim much harder. It belongs in your handover pack on the day you get the keys back.
How do I look after a new bathroom so the warranty holds?
Keep the silicone joints sound, because that is the first thing to fail and the easiest to renew. Reseal natural stone on the schedule the supplier gives you. Run the fan or open a window so steam does not sit and grow mould. Report any tile movement, damp patch or grout crack early, while it is a small fix and clearly inside the warranty, not after it has become water damage.
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