What Is a Waterproofing Certificate?
A waterproofing certificate is a formal document issued by a QBCC licensed waterproofing contractor confirming that the waterproofing work carried out at a property complies with the relevant Australian Standards, specifically AS 3740-2021 for domestic wet areas.
In Queensland, the QBCC Form 43 (Compliance Certificate for Waterproofing) is the standard document used. This certificate serves as your proof that the bathroom, shower, laundry, balcony, or other wet area has been waterproofed to the required standard. It is not just a receipt for services rendered. It is a compliance document with legal and financial implications.
The certificate is typically issued after the waterproofing membrane has been applied and inspected but before tiling or other covering work begins. This timing is important because once tiles are laid, the membrane cannot be inspected without destructive investigation.
What Is QBCC Form 43?
QBCC Form 43 is unique to Queensland and is the formal compliance certificate for waterproofing work. It is issued by the QBCC licensed contractor who performed the waterproofing and certifies that the work meets AS 3740-2021 requirements.
The form requires the contractor to declare: - Their QBCC licence number and details - The property address and specific areas waterproofed - The membrane system used, including manufacturer and product names - That the work complies with AS 3740-2021 - The date of application and completion
QBCC Form 43 is a legal document. If the contractor provides a false or misleading declaration, they face penalties under the Queensland Building and Construction Commission Act. This gives homeowners an additional layer of protection compared to generic certificates used in other states.
Building certifiers in Brisbane will typically require a completed QBCC Form 43 before signing off on wet area construction or renovation. Without it, your building approval process can stall.
What Should a Waterproofing Certificate Include?
A proper waterproofing certificate should contain several key pieces of information. If your certificate is missing any of these elements, it may not be accepted by building certifiers, insurers, or conveyancers during a property sale.
Essential information includes:
Contractor details: The full business name, ABN, and QBCC licence number of the contractor who performed the work. Verify the licence through the QBCC online licence search.
Property details: The full address of the property and a clear description of which areas were waterproofed (e.g., "main bathroom floor and walls," "ensuite shower recess," "first-floor balcony").
Membrane system details: The manufacturer name, product names for all components (primer, membrane, reinforcing tape), and ideally batch numbers. This information is critical for warranty claims.
Application details: The date(s) of membrane application, the number of coats applied, and the dry film thickness achieved (if measured).
Compliance statement: A clear statement that the waterproofing work complies with AS 3740-2021.
Inspection details: Whether the work was inspected, by whom, the date of inspection, and whether flood testing was performed.
Photographic evidence: While not always included, best-practice certificates include dated photos of the completed membrane before tiling. These photos are invaluable if a dispute arises later.
Contractor signature: A signed and dated declaration by the QBCC licensed waterproofing contractor or their authorised representative.
When Do You Need a Waterproofing Certificate in Queensland?
You need a waterproofing certificate whenever waterproofing work is carried out on your Brisbane property. The most common situations include:
New builds: Every wet area in a new home requires waterproofing certification as part of the building approval process. The building certifier will request QBCC Form 43 for each wet area before approving the next stage of construction.
Bathroom renovations: If you are renovating a bathroom and the waterproofing is being replaced (which it should be during a full renovation), you need a certificate for the new membrane. This applies whether you are doing a complete gut renovation or replacing a shower recess.
Shower replacements: Even replacing just a shower recess requires waterproofing certification if the membrane is disturbed or replaced.
Balcony and deck waterproofing: External waterproofing on balconies, decks, and terraces should be certified, particularly for multi-storey buildings where a leak could damage units below.
Insurance claims: If you need to make an insurance claim related to water damage, your insurer may request evidence that the waterproofing was professionally installed and certified. Missing certification can weaken your claim.
Property sale: Increasingly, Queensland conveyancers and building inspectors request waterproofing certificates during the pre-purchase inspection process. Having certificates available demonstrates due diligence and can speed up the sale process.
What If You Are Missing a Waterproofing Certificate?
If you do not have a waterproofing certificate for work that was previously carried out, you have several options:
Contact the original contractor: If you know who performed the waterproofing work, contact them and request a copy of the certificate. Many contractors keep records and can issue a duplicate.
QBCC records: The QBCC may have records of licenced contractors who worked on your property, particularly if building approvals were obtained. Contact the QBCC to enquire.
Building certifier records: If the work was part of a building approval, the certifier or local council may have a copy of the certificate on file.
Commission a waterproofing inspection: If the original certificate cannot be located, you can engage a QBCC licensed waterproofer to inspect the existing waterproofing (which may involve removing a section of tile to inspect the membrane) and provide an assessment. This is not the same as a compliance certificate for the original work, but it can provide evidence of the current condition.
Replace the waterproofing: In some cases, particularly for older properties where the waterproofing is of unknown age or quality, the most practical solution is to have the waterproofing replaced by a QBCC licensed contractor who will issue a new Form 43 certificate. This is especially advisable before selling a property.
How to Verify a Waterproofing Certificate
To verify that a waterproofing certificate is legitimate and the contractor is properly licensed, take these steps:
1. Check the QBCC licence: Go to the QBCC website (qbcc.qld.gov.au) and use the licence search tool. Enter the contractor's licence number from the certificate and verify that it is current and covers waterproofing work.
2. Confirm the contractor details: Verify that the business name and ABN on the certificate match the QBCC licence registration.
3. Check the membrane product: Verify that the membrane product listed on the certificate is a recognised product that complies with AS 4858. Most major manufacturers (Gripset, Ardex, Sika, Mapei) have product compliance certificates available on their websites.
4. Confirm inspection: If the certificate references an inspection by a building certifier, you can contact the certifier to confirm.
5. Request photos: If the certificate does not include photos of the completed membrane, ask the contractor to provide them. Any reputable waterproofer will have taken photos during the project.