The fight against water seepage is an enduring battle for the wary homeowner.
Even a small unchecked leak can wreak untold devastation across the built area, causing extensive damage to wall and floor materials, offering fertile ground for toxic mould and bacteria, and undermining the structural integrity of the building, rendering internal spaces uninhabitable.
As the last line of defence against below-grade water ingress, a quality waterproofing system is vital to the health and amenity of the built area, arresting leaks before any breach of the building substrate.
Yet in an industry riven by inconsistent building standards, it seems too many homeowners are left to rue the consequences of poor waterproofing installations.
According to a recent survey by the Queensland Building and Construction Commission (QBCC) complaints regarding defective waterproofing rank third highest of all building work grievances. Worse still, waterproofing consistently rates as the most common reoccurring building defect – an unacceptable failure risk for today’s homeowners.
Despite major innovations in hydrophobic membrane technologies over the last 50 years, it seems the pressure on builders to ensure waterproofing systems are cost-effective, easy-to-apply and environmentally friendly has increased their susceptibility to failure.
However, few could deny that the costs of waterproofing failure far outweigh the expense of ensuring quality and rigour behind every waterproofing installation.
After all, the potential fallout from waterproofing failures could leave installers (as well as hapless homeowners) liable for costly, extensive and immediate repair: from manual removal of floor/wall tiles, and water-affected substrate, to the full reapplication of waterproofing membranes.
Expert Advice for Waterproofing Linear Drainage Systems
Waterproofing membranes form the primary protective layer for the entire wet area – a crucial provision for all drainage installations.
Without quality materials, rigorous installation and strict adherence to Australian waterproofing standards, leakage into vulnerable building structures will be all but inevitable.
While construction professionals are more than likely to be familiar with the requirements for traditional centralised drainage installations, the same cannot be said for the increasingly in-demand linear drainage system.
The unprecedented popularity of level-plane lineal drainage over the last decade has left many building and construction professionals on the proverbial back foot, unaware of the unique installation and regulatory requirements for waterproofing linear systems.
Reassuringly, linear waterproofing installations share many similarities with traditional centralised systems; however, the expanded dimensions of the linear drainage channel mean that some key differences are inevitable.
Indeed, one of the unique design features allowed by linear drainage systems is the unenclosed (or barrier-free) wet area design. For barrier-free installations, the AS3740 (‘Waterproofing of wet areas within residential buildings’) requires liquid or fabric membranes to be applied a minimum 150mm above the floor substrate, and 25mm above the maximum retained water level.
A crucial provision of all hobless wet area designs is the installation of quality waterstops (which prevent the passage of water across construction joints). For all unenclosed shower designs, the AS3740 requires waterstop terminations to be set at a minimum distance of 1500mm from the shower rose.
Whether building for a modern linear or a traditional centralised drainage solution, it is clear that any chosen waterproofing treatment must be tailored to the unique conditions and dimensions of the wet area.
For more advice on achieving failsafe waterproofing for linear drainage installations, including 9 specialised tips for wet area construction professionals, download Stormtech’s free experts’ guide to waterproofing.
