Leaking Balcony in a Strata Building – Who Pays in NSW?

The short answer: it depends where the boundary sits in your strata plan – and that’s genuinely different building to building.

We’re waterproofers, not lawyers, so treat this as how it usually plays out in practice rather than legal advice. For your specific building, your strata manager and your strata plan are the authority.

The general position in NSW

In most NSW strata schemes, the structural slab and the original waterproofing membrane are common property. That puts them with the Owners Corporation.

Tiles, grout and surface finishes are more contested. If they were part of the original construction at registration, they’re often common property too. If a previous owner retiled the balcony themselves, that’s usually a different conversation.

And plenty of schemes have by-laws granting exclusive use of balconies to individual lots, which can shift maintenance obligations onto the owner. If your building has one of those, it changes the answer.

Why the argument happens

Almost every one of these disputes comes down to the same unanswered question: what actually failed?

If nobody knows whether it’s the membrane, the tiles, the drainage outlet, the door threshold or a planter box, then everyone can argue it’s someone else’s component. The dispute isn’t really about the law – it’s about the missing diagnosis.

What usually moves it along

An independent inspection and a written report identifying the source. Once there’s a document saying “the membrane has failed at the upstand, here are the photographs”, the responsibility question usually answers itself.

It also stops the cycle where an owner pays for a repair, it leaks again, and everyone starts from scratch.

What actually fails on a balcony

So you know what a report is likely to find:

• The membrane at the upstand – where it turns up the wall, or at the door threshold
• The drainage outlet – blocked, badly detailed, or set too high so water ponds
• Falls – if the balcony doesn’t drain, water sits, and standing water finds every weakness
• The edge – where the slab meets the balustrade or the drip edge
• Planter boxes – permanently wet soil on a structural slab, one of the most reliable leak sources in Sydney apartments
• The door threshold – very often the actual culprit when water appears just inside

If you’re a committee comparing quotes

Get a scope first, then quote it. If you send three contractors to a leaking balcony with no defined scope, you’ll get three prices for three different jobs and no way to compare them.

A proper balcony remediation generally means stripping back to the slab, repairing the substrate, correcting the falls, re-detailing the junctions, laying a membrane rated for exposure, flood testing it, and re-tiling with movement joints.

A quote that’s dramatically cheaper than the others has usually left something on that list out. It’s worth asking which.

Need someone to look at it?

We inspect before we quote, across Sydney. Call 0450 679 512 or email sam@sydneychoicewaterproofing.com.au.

NSW Contractor Licence 299661C · Fully insured · 7 year warranty