Insights
Strata committee waterproofing FAQ
Plain answers to the questions NSW strata committees, strata managers and owners ask us most about apartment waterproofing.
How long does waterproofing last in an apartment building?
There is no guaranteed lifespan. A well-designed and well-installed external membrane is generally expected to last around fifteen years or more, with real-world service life commonly between ten and twenty-five years. The building, though, is designed to last far longer than that, so good waterproofing never relies on the membrane alone. It assumes the membrane will eventually fail and builds a second line of defence behind it. A planter or balcony, for instance, can be detailed with a secondary retaining wall, a raised hob and its own drainage, so that even when the primary membrane gives out, water is still collected and carried away from the wall rather than into the apartment below. The membrane is only the first line of defence. The detailing around it is what keeps the building dry for the decades the membrane will not. Why waterproofing fails →
Who is responsible for waterproofing in a strata building in NSW?
In most cases the owners corporation, because external walls, roofs and balcony membranes are usually common property. Under section 106 of the Strata Schemes Management Act 2015 the owners corporation has a strict duty to maintain and repair common property, and a lack of funds is not a defence. Whether a particular area is common property depends on the registered strata plan, so check it before assuming. How remediation works →
What happens if my builder goes bankrupt?
Honestly, often less than you would hope. The company that built your building may no longer exist, and although the statutory duty of care under the Design and Building Practitioners Act can in theory reach others who were involved, in practice many owners spend a great deal on lawyers and recover little. We are not lawyers and we will not pretend a legal fight is the answer. What we have seen work is putting that money into a properly diagnosed and properly designed repair, so the building is dry and saleable again instead of tied up in a case that goes nowhere. Read why we exist →
What is a serious defect under the DBP Act?
The term serious defect is actually defined in the Residential Apartment Buildings Act, which works alongside the Design and Building Practitioners Act. It includes a defect in a building element, and waterproofing is one, that breaches the Building Code, the relevant Australian Standards or the approved plans, or a defect that makes part of the building unsafe or unfit to use. Waterproofing failure frequently meets this definition. Read more →
Do I need an architect or an engineer for waterproofing?
For apartment buildings, waterproofing is a regulated design under the Design and Building Practitioners Act, so it must be designed and declared by a registered design practitioner, which can be a registered architect or an appropriately registered engineer. The more important question is independence: you want whoever designs the repair to be someone other than the contractor pricing the work. See our approach →
How much does it cost to remediate waterproofing in an apartment?
It depends on the cause and extent, which is exactly why diagnosis comes first. Our initial Class 2 waterproofing consultation is a fixed fee of $660 and includes a diagnostic site visit. Detailed investigation and remediation design are quoted once the scope is clear, and we then oversee specialist builders who carry out the repair against the design, so it is fixed for good. Book a consultation →
Can I claim insurance for waterproofing defects?
Sometimes, but most standard building insurance excludes defective workmanship, so a straightforward claim is often not available. Once mould takes hold, premiums commonly rise and some insurers decline to renew. Decennial Liability Insurance, where a building has it, can respond to serious defects in common property without proving fault, but it is currently voluntary in NSW and most existing buildings do not carry it. Learn what applies →
What is a Class 2 building?
A Class 2 building is a residential building containing two or more separate dwellings, which in practice means an apartment or unit block. A single apartment sitting above another dwelling or above a shop is also a Class 2 unit, and a building can be Class 2 in part. This is the building class the Design and Building Practitioners Act and the Residential Apartment Buildings Act are written for. About Class 2 work →
How do I prove waterproofing defects in court?
With evidence, which means an independent expert report identifying where water enters, where it travels and where it appears, supported by testing and clear documentation. A scope of works or a contractor's quote is not evidence of cause. Committees who act without proper documentation are at a serious disadvantage in any claim under the Design and Building Practitioners Act. What good documentation looks like →
What is the difference between Project Intervene and Project Remediate?
They are two different Building Commission NSW programs. Project Intervene helped owners corporations resolve serious defects, mainly waterproofing and structural problems, in apartment common property by having the Commissioner broker rectification with the developer. Project Remediate funded the removal of dangerous combustible cladding through ten-year interest-free loans. Both are now closed to new registrations. Read the guide →
When did Project Intervene registrations close?
Project Intervene registrations closed on 30 November 2023. The program accepted 227 matters before closing, covering tens of thousands of apartments. It is now closed to new registrations, though owners can still lodge a building defect complaint with Building Commission NSW. What to do now →
What is Decennial Liability Insurance?
Decennial Liability Insurance, or DLI, is a ten-year insurance attached to a building that can cover serious defects in common property, including waterproofing, without owners having to prove fault. In NSW it is currently voluntary, available as an alternative to the strata building bond, and the Government has signalled an intention to make it mandatory in future, though that is not yet law. Most existing buildings do not have it. Read more →
Book a Class 2 waterproofing consultation
Send the building address and a few photos. We will tell you whether it sounds like a quick win or a bigger problem, and what an independent investigation would cost.
Or call 0405 837 228