The trouble with Waterproofing

Waterproofing is one of the most common building defects reported by property owners in Brisbane to the QBCC. Defective waterproofing can cause a great deal of damage to property and is often caused by poor installation practices.

AS4654.2 is the Australian Standard for the design and installation of external, above-ground waterproofing membranes. Balconies, terraces, and roof decks need to be designed & built using this standard as a minimum target. All too often we find this standard is either not known or entirely ignored at many stages of the build process. From design, through construction, and even at the final inspection, the requirements of this standard are often not met.

One of the most common failures is caused by directly sticking tiles to membranes that are not suitable for large areas, particularly in external applications.

On our latest project, The Hawthorne siblings project 101, we utilised a fairly new product on the market called pedestals.

What are pedestals?

Pedestals are plastic assemblies typically consisting of a wide base, a height-adjustable mechanism, and a mounting assembly to suit the surface finish. Made predominantly from recycled plastics, they are a sustainable solution to paver and deck installation.

Mounting assemblies are as varied as the heights of the pedestals. When used with suitable tiles or pavers the mounts come with spacer tabs ranging from 2mm to 10mm. These tabs create positive drainage while eliminating uneven grout lines and preventing efflorescence. Variable spacer tabs enable pedestals to support up to six pavers with varying corner angles. You can even utilise joist hangers to make building a deck a simpler, faster process.

Complete pedestal systems can include other attachments to aid installation and create the perfect finish. Wall spacers can be used to keep the paver off the walls or upstands to allow for expansion, contraction, and paver movement due to traffic. EPDM shims can be installed to act as a shock absorber, to prevent paver slip, and to compensate for stone thickness at installation. And wind uplift retainers can be utilized on exposed installations to increase wind uplift resistance.

Using pedestals allows you to use a superior waterproofing membrane that is suitable for external applications, much superior than the membranes commonly used. This goes a long way to avoid common leaks.

In the off chance a problem does arise, they allow you to simply lift some up to inspect further.

View the brilliant work from our team on our recently completed project the Hawthorne Siblings Project101.

REFRENCES

https://www.thewaterproofers.com.au/articles/pedestals/

https://www.qbcc.qld.gov.au/blog/tradie-talk/trouble-waterproofing (removed)