When done correctly, it protects wet areas and structural elements from water damage for years. When it fails, the resulting damage can be expensive, disruptive and difficult to resolve.
For home owners, understanding how to reduce the risk of waterproofing problems, and how to recognise early warning signs, is key to protecting your home, your health and your financial investment.
An informed home owner is a protected home owner
Waterproofing problems can be costly, but many are preventable. To put that into perspective, the financial toll of these defects is significant. Each residential bathroom claim finalised under the Queensland Home Warranty Scheme during the 2024–25 financial year averaged almost $25,000 in rectification costs. By choosing licensed contractors, insisting on proper contracts, allowing work to be done correctly and understanding early warning signs, home owners can greatly reduce the likelihood of defects and disputes.
Being informed is one of the strongest protections a home owner has.
Getting waterproofing right from the start
A critical first step is always using appropriately licensed contractors. In Queensland, waterproofing is regulated work and must be carried out by licensed professionals. While recommendations or gut instinct may feel reassuring, they are not a substitute for checking a contractor’s licence and track record. A licensed contractor is more likely to understand compliance requirements, industry standards and their legal obligations.
Equally important is ensuring you have a written, signed and dated contract in place before work begins. You can download the appropriate contract template as a guiding resource and for your peace of mind. A quote (even if accepted) is not the same as a contract. A proper contract clearly sets out the scope of works, what areas will be waterproofed, what products will be used, timeframes and responsibilities. This clarity provides peace of mind and can significantly reduce misunderstandings if issues arise later.
Home owners should also ensure waterproofing is not rushed. Waterproofing systems require proper surface preparation, correct detailing and adequate curing time between coats. Tiling or finishing too soon can compromise the membrane before it has properly set.
Finally, be aware that waterproofing systems can be damaged after installation. DIY renovations, drilling, or later works by other tradies can easily puncture membranes hidden behind tiles. Coordinating works carefully and seeking professional advice before making changes can prevent accidental damage.
Ongoing care is everything
Even correctly installed waterproofing is not “set and forget”. Over time, normal wear and tear can affect seals, grout and finishes that protect the membrane underneath.
Home owners can reduce risk by:
- replacing silicone joints every few years
- promptly repairing cracked grout or loose tiles
- keeping drains clear to avoid ponding water
- avoiding harsh or corrosive cleaning chemicals.
Simple maintenance actions can significantly extend the life of waterproofing systems.
Red flags to watch for after installation
Waterproofing failures often develop slowly. Early warning signs should never be ignored.
One of the most common indicators is a persistent musty smell or mould growth, particularly in bathrooms, laundries or adjoining rooms. This often points to trapped moisture behind walls or floors.
Other warning signs include:
- peeling, bubbling or blistering paint
- peeling or discolouring silicone joints
- discoloured or stained ceilings and walls
- damp patches that worsen after showers or rain
- loose tiles or crumbling grout
- white, chalky residue on surfaces, indicating moisture movement.
While these signs may appear minor at first, they can indicate a larger underlying issue.
What to do if you suspect a problem
If you notice potential waterproofing defects, early action is critical. Document the issue with photos and written notes and notify your licensed contractor in writing as soon as possible. This gives them the opportunity to inspect and rectify the problem before further damage occurs.
If the issue cannot be resolved, you may be eligible to make a claim under the Queensland Home Warranty Scheme. The scheme provides insurance cover for home owners where residential building work is found to be defective and the responsible contractor is unable or unwilling to rectify the work. Strict eligibility criteria, timeframes, limitations and policy conditions apply.
