Why Waterproofing Disputes Are So Common in NSW Apartments

In NSW, apartment buildings are governed by the Strata Schemes Management Act.

Waterproofing issues often fall into a grey area because they may involve:

• Common property

• Lot property

• Structural components

• Surface finishes

• External balconies

• Internal bathrooms

The confusion usually arises when water leaks from one unit into another — and both parties believe the other is responsible.

Apartment Waterproofing Responsibility NSW – The Core Rule

Under NSW strata law:

🔹 The Owners Corporation (Strata) is responsible for common property.

🔹 The Lot Owner is responsible for lot property.

But here’s where it gets complicated…

Waterproofing membranes are often considered part of the building’s structure — meaning they may be classified as common property.

However, tiles and surface finishes are usually the lot owner’s responsibility.

That distinction determines who pays.

Who Pays for Balcony Leaks in NSW?

Balcony leaks are the #1 waterproofing dispute in NSW strata buildings.

Responsibility depends on:

• Whether the membrane is common property

• Whether the tiles are cosmetic finishes

• Whether previous renovations were done without approval

• The original strata plan wording

General Rule:

In most cases, the waterproofing membrane beneath balcony tiles is considered common property, meaning strata may be responsible.

However:
If a lot owner renovated the balcony and altered waterproofing without approval, they may become liable.

This is why reviewing the strata plan is critical.

Strata Waterproofing Rules for Bathrooms

Bathroom leaks are slightly different.

In NSW apartments:

• Waterproofing membranes are often classified as common property

• Tiles, grout and fittings are usually lot owner property

If a bathroom leak is caused by:

• Failed membrane → usually strata responsibility

• Cracked tiles or poor renovation → usually lot owner responsibility

Again, documentation matters.

What About Renovated Bathrooms in Apartments?

This is where many disputes occur.

If a lot owner:

• Renovated their bathroom

• Replaced the membrane

• Did not get strata approval

They may assume full responsibility for waterproofing defects — even if membranes are normally common property.

Strata by-laws can also shift responsibility depending on renovation approvals.

Always check:

• Strata by-laws

• Renovation approval documents

• Common property definitions

How NSW Determines Waterproofing Responsibility

To determine responsibility, strata managers or building consultants typically review:

1. The strata plan

2. The by-laws

3. The building’s original waterproofing scope

4. Inspection findings

5. Cause of failure

A professional waterproofing inspection in Sydney can help determine whether:

• The failure is structural

• The membrane failed

• Poor workmanship caused the leak

• Drainage non-compliance is involved

What Happens If Responsibility Is Disputed?

If strata and lot owners disagree:

• An inspection report is commissioned

• Mediation may occur

• NSW Civil and Administrative Tribunal (NCAT) may be involved

Waterproofing disputes in NSW can cost tens of thousands if not handled properly.

Early investigation is always cheaper than litigation.

Who Pays for Waterproofing Repairs in Strata?

In summary:

⚠️ But always confirm with strata documentation.

Why Documentation and Compliance Matter in 2026

In 2026, NSW building compliance standards are stricter.

Lack of:

• Waterproofing certificates

• Inspection records

• Approval documentation

Can make responsibility disputes worse.

If waterproofing was not compliant with AS3740 or AS4654, liability may shift depending on fault.

When to Get a Waterproofing Inspection in Sydney

You should arrange an inspection if:

• Water is entering another apartment

• Balcony leaks are damaging ceilings

• Insurance requires proof of cause

• Strata is disputing liability

• Renovation work has recently been done

A proper inspection can determine:

• Source of leak

• Membrane condition

• Drainage compliance

• Structural impact

Final Answer: Who Is Responsible for Waterproofing in NSW Apartments?

There is no one-size-fits-all answer.

In NSW strata apartments:

• Membranes are often common property

• Surface finishes are usually lot owner responsibility

• Renovation approvals can shift liability

• Strata by-laws may override assumptions

The only way to know for certain is:
✔ Review strata documents
✔ Conduct a professional inspection
✔ Identify the true cause of failure

Need Help with a Strata Waterproofing Issue in Sydney?

Waterproofing disputes can escalate quickly and become expensive.

If you’re dealing with:

• Balcony leaks

• Bathroom membrane failure

• Strata responsibility disputes

Hills Waterproofing provides professional inspections and compliant waterproofing solutions across Sydney.

📞 Book a waterproofing inspection before the damage spreads.

FAQ

❓ Is strata responsible for waterproofing in NSW apartments?

In many NSW apartment buildings, waterproofing membranes are considered common property, meaning the Owners Corporation (strata) is often responsible. However, responsibility can vary depending on the strata plan, by-laws, and whether the area was renovated by the lot owner.

❓ Who pays for balcony leaks in strata buildings?

Balcony waterproofing membranes are usually classified as common property in NSW, so strata may be responsible. However, if a lot owner carried out unapproved renovations or altered the membrane, they may be liable for repairs.

❓ Are bathroom waterproofing membranes common property in NSW?

In most NSW strata schemes, the waterproofing membrane beneath bathroom tiles is considered common property. Surface finishes like tiles and grout are typically the lot owner’s responsibility.

❓ What happens if waterproofing fails in an apartment?

If waterproofing fails, strata or the lot owner may need to commission an inspection to determine the cause. Responsibility is based on whether the failure relates to common property, renovations, or structural issues.

❓ How do strata waterproofing disputes get resolved in NSW?

Disputes are typically resolved through inspections, mediation, or applications to the NSW Civil and Administrative Tribunal (NCAT) if agreement cannot be reached.

❓ Do I need a waterproofing inspection before claiming insurance?

Yes. Most insurers require evidence identifying the source of the leak and whether the waterproofing complies with Australian Standards before approving claims.