Waterproofing is somewhat of a slippery issue in the design and construction industries. Every year, insurers pay out millions of dollars to cover damage related to water ingress, however from a regulatory perspective, it remains a notoriously tricky area to navigate. This is a somewhat puzzling situation, given the crucial importance of wet areas within our residences and buildings.

“Not getting waterproofing right is, firstly, an issue of structural integrity,” says Max Rafferty, Master Builders Australia National Technical Policy Manager. “If you get the wet areas wrong, you’ll get damage to frameworks, whether they be metal, timber, or wood. Second, it’s an issue of health. You hear about asthma, you hear about mould growth, and all these things bear consideration. On the plus side, technology has come a long way in the last 40 years. New waterproofing technology is amazing, and you're looking at everything from liquid applied membranes, all the way through to sheet membranes and vinyls. But I think as we're all aware, technology will not save us from poor design or poor workmanship.”

And while it might seem like waterproofing should be a fairly straightforward matter of finding a suitable membrane and installing it properly as required, the reality is far more nuanced than that. Complex regulatory frameworks that differ from state to state, as well as understanding the various climatic conditions that impact overall building design and how they relate to weatherproofing and waterproofing, make it an area of significant expertise within the industry.

“Wet area design and construction is a bit of a mystery to a lot of people within the industry. The frameworks we've got to work within don't present themselves in a really straightforward manner - it's very difficult to work your way through the design and construction logic of construction of these spaces. And there are complexities in the materials and how they go together. There's things that work with them and things that don't. And so things that seem simple, can be an absolute trap for young players.”

The standard for waterproofing is AS 3740—2010: Waterproofing of domestic wet areas. Max is of the  opinion that while the standard does serve a purpose, it’s in need of overhaul to make it more user friendly, and more relevant to the realities of the industry. “The standard is only the minimum standard - it essentially translates into, ‘well, what's the least we can do to make sure something functions appropriately?’, and that’s it.” says Max. “I think that that's where a lot of standards are at the moment. And I think the industry looks at the current standard and thinks we could really use a change.”

“They're rich in information,” he continues, “but not so rigid in storyline. And I think what we're looking for is a way to communicate that information clearly, and without sending everybody to sleep. It needs to be written with the end audience in mind, and with a focus on overcoming the challenges for designers and for builders or subcontractors in actually putting these spaces together.”

To overcome this communication problem, Max advocates for greater industry involvement in setting these standards, so that the end product not only reflects the realities of construction in practice, but shows construction professionals how to go beyond the bare minimum to ensure that work is completed to the highest standard possible. He laments that across the industry professionals often turn to product manufacturers for information, which invites obvious bias into which products are recommended, and does not guarantee the best outcome.

So what’s the solution here? For Max, this is a communication problem, not a regulation problem. Making the existing standards easier to read and follow in practice is a big step towards ensuring that our buildings are properly waterproofed. “Ultimately, it’s the homeowners and occupants of these buildings that are most invested in making sure the work is done properly, so they should also be able to understand what needs to be done. That’s how we need to be thinking. If a Mum or Dad consumer can pick one of these documents up and say, ‘Oh, that's how that works,’ then great - the rest of the industry should have no problem.”

Listen to the full interview with Max Rafferty on Talking Architecture & Design Podcast. 

This podcast was bought to you in association with Stormtech, proud sponsors of the Residential Series of podcasts.