WATERPROOFING

Making waterproofing easier

WORDS MATT MCDONALD

Always a time-consuming and painstaking task, waterproofing is also something you want to get right the first.

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...the good news is that, because of the introduction of the latest generation of waterproofing products, the job is now easier than it’s ever been.

Waterproofing is important. Though it accounts for only a fraction of the total cost of residential construction projects, if not done correctly, it can result in significant repair costs (and associated headaches).

Whether discussing internal applications and the waterproofing of wet areas (like bathrooms, kitchens, laundries, and so on) or external applications (and the waterproofing of roofs, external walls, balconies, gutters, foundations, etc.), the consequences of not ensuring this task is completed correctly are hardly worth contemplating.

To be specific, the problems associated with inadequate waterproofing include the promotion of mould and mildew, rising damp, swelling walls, rotting timber, and structural damage. All serious and difficultto-rectify problems, they also represent cost burdens (both financial and in terms of health and safety).

All considered, the message to specifiers is simple. When it comes to waterproofing, get it right the first time. Ensure that your bath areas, laundries, taps, drains, roofs, and balconies are correctly attended to and adhere to NCC requirements.

The good news is that, because of the introduction of the latest generation of waterproofing products, the job is now easier than it’s ever been.

ARDEX

The Weldtec waterproofing membrane range from Ardex Australia includes sheet applied products that are made of synthetic rubber and therefore able to resist ageing, while remaining flexible enough to accommodate structural movements.

Designed for simple installation by Ardex-trained contractors, these products are suitable for use everywhere from rooftops to basements. They feature laps and seams that are heat-welded and can be relied upon to provide a guaranteed watertight system. Weldtec waterproofing membranes resist tearing and flex-cracking, can be directly tiled, directly screeded, and flood tested just one hour after installation. They form a continuous and consistent membrane thickness that is compliant to relevant Australian Standards.

Products in the range include: • Ardex WPM 1500 – A high performance below ground tanking waterproofing membrane suitable for geothermal conditions, tanking foundations, basements, and all other below ground waterproofing. • Ardex WPM 750 - A safe and secure under tile waterproofing solution suitable for use with under tile heating systems. • Ardex Root Repell – A versatile weldable waterproofing membrane that features a root inhibitor and is therefore perfect for planter boxes, retaining walls and living roofs. • Ardex WPM 712 / WPM 715 – A high quality, heat-welded waterproofing membrane designed for use in exposed areas, this system has properties that ensure it resists ageing when exposed to heat, sunlight and ozone. • Ardex WPM 1000 - A high performance, easy-to-install waterproofing membrane suitable for tanking, rooftops, decks, under tiles, pavers, pond linings, and cavity door flashings.

BEAUMONT TILES

The Wedi Shower System, a German-made waterproofing system available from Beaumont Tiles, cuts the four days traditionally required to complete sheeting, screeding and waterproofing down to just four hours. As such, it represents something of a game changer for waterproofing applications, significantly cutting labour time and overall costs.

Australian Codemark certified and the system promises to significantly expand the design possibilities for showers, baths, and other wet areas. Because it doesn’t involve the application of waterproof roll-on or sheet membranes, the issue of unexpected cracks and pinholes (as experienced in those traditional systems) is eliminated.

Completely waterproof, the Wedi Shower System also eliminates the associated problems of mould and mildew. Its blue XPS closed cell foam core remains fully functional even in cases where it is inadvertently damaged.

Wedi waterproof building boards can be used as an underlay and they represent an suitable substrate for tile or stone. In such applications, they provide a pre-sloped flat surface and can be relied upon to form a solid bond with tile and stone adhesives.

GTEK (BGC PLASTERBOARD)

Featuring a high-performance lining that is the first of its type available in Australia, Gtek Barrier ensures superior waterproofing performance in wet and high humidity areas, such as bathrooms and laundries. Ideal for use on walling and as a substrate under tiles, it is also resistant to abrasion and therefore suitable for use in high traffic areas that are not tiled.

With a core similar to standard wet area plasterboard, Gtek Barrier’s key differentiator is the celluloic glass fibre scrim that lines its front and back. Orange in colour and therefore easy to identify, this high-performance liner features recessed edges. Available in two thicknesses (10 mm and 13 mm) it repels moisture, while at the same time preventing other materials, such as paint or adhesives, from adhering to it.

A lightweight product, Gteck barrier is installed using the same techniques used to install standard wet area plaster boards. However, it is easier to cut and fasten than those traditional alternatives. It has a 35kg/m² tile carry weight capacity and a low absorption core. This eliminates the probability of water wicking, and therefore prevents the possibility of damage to supporting structure and wall finishes.

TREMCO

Available from Tremco, Alphaguard BIO is a waterproofing system designed specifically with roofing restoration jobs in mind. A composite system, tested to AS4654.1 and compliant with the external waterproofing regulations of the NCC, it cures to form a seamless, monolithic membrane over a range of roofing materials.

Significantly, given that it is specifically recommended for roofing restoration work, Alphaguard BIO can also be applied over existing membranes. This simplifies the restoration process, while minimising disruption to homeowners and delivering an additional 20 years of life to their roofs.

Alphaguard BIO is a 100% solids polyurethane-based technology that can be applied over existing waterproofing systems, including liquid or sheet membranes, and torch on applications. A flexible system, it allows for an alternative specification which is primer, base coat, Permafab reinforced fibre sheet and top coat. This specification increases the resistance to potential tearing or damage.

The fact that is made of solid materials means that the thickness of the membrane remains consistent from the time of application until after it is fully cured. Discrepancies are avoided and customers always know exactly what they are paying for.

On top of that, this waterproofing system it’s highly durable and UV resistant. It’s white top coat ensures it reflects a significant amount of solar energy and is therefore compliant with Section J1.3(b) of NCC 2019.

GRIPSET

Gripset BRW-PFN is a self-adhesive butyl rubber sheet membrane with a sealing edge that is suitable for the waterproofing of internal and external wet areas. It features a high strength needle punched fabric facing and a fibre Reinforced Butyl rubber backing. The latter ensures effective waterproofing performance as well as impressive resistance to vibration, flexing, and other movement. As such, Gripset BRW-PFN outperforms liquid membranes when used in similar applications.

And, because it forms an instant seal as soon as it is applied to the intended surface, it minimises downtime and maximises cost efficiency. Once this seal is established, it can be finished over with the finish of choice – including everything from adhesives, membranes, and coatings, to screeds, mortars, renders, and other approved decorative finishes.

Gripset BRW-PFN delivers reliable performance across a wide temperature range (- 30°C to 80°C) and is compatible for use as a multi-layered system with BRW HD.

Suitable substrates include glazed surfaces, marble, granite, ceramics, soft and rigid plastics, PVC, DPC films, primed or dense concrete, compressed CFC sheeting, galvanised iron, zincalume, copper, aluminium, timber sheeting, structural floor sheeting; and existing coatings such as epoxy, polishes, paint surfaces.

FOSROC

Fosroc’s Nitoproof range of above ground and wet room liquid membranes includes solvent-based polyurethanes, water-based polyurethanes and acrylic options.

The liquid product range includes spray and hand applied products. The sprayapplied Polyurea range, Polyurea WHE110 (hybrid polyurea) and Polyurea WPE110 (pure polyurea) are certified and compliant to AS4654.1 (external above ground) and AS4020:2018 (potable water) respectively.

Meanwhile the hand-applied Nitoproof systems offer flexible solutions in both one part moisture cure and two-part alternatives. These products are compliant and certified to AS4654.1 and AS4020:2018, providing a broad selection of solutions whether the finish is to be tiled, paved or exposed.

The company also offers spray applied Polyurea WHE110, as well as self-adhesive and torch on sheet membranes such as Proofex 3100 and the new Proofex Torchseal range; hand and spray applied liquid solutions; and cold and hot applied sheet membranes.

Fosroc also offers a variety of primers for use with its waterproofing systems (noting that choice, in these terms, depends upon the type and nature of the substrate and the technology of the membrane being used).

RHINO LININGS

Spray applied and totally seamless, Rhino Linings waterproofing membranes are suitable for a broad range of applications across the construction and industrial sectors. Able to bond with virtually any other surface, to transcend multiple substrates, and eliminate potential weaknesses associated with other joined membrane products, they are amongst the most reliable products of their type available.

A product that combines maximum slip resistance with excellent protection against impact, abrasion and corrosion, Rhino Tuff Stuff can carry a range of finishes from light to heavy, though for residential applications the lighter finishes are more commonly chosen.

Applied as a thicker membrane than comparable products, it also outperforms those alternatives in terms of slip resistance, vibration absorption, and noise absorption. When cured, it creates a monolithic seamless coating, and is able to conform to any shape and size over substrates of any dimensions and materials including all metals, concrete, wood and fibreglass, encouraging their independence.

SUPPLIERS Ardex architectureanddesign.com.au/suppliers/ardex-australia Beaumont Tiles architectureanddesign.com.au/suppliers/beaumont-tiles GTEK [BGC Plasterboard] architectureanddesign.com.au/suppliers/bgc-plasterboard Tremco architectureanddesign.com.au/suppliers/tremco Gripset gripset.com Fosroc architectureanddesign.com.au/suppliers/dulux Rhino Linings architectureanddesign.com.au/suppliers/rhino-linings-australasia-pty-ltd