Sika has provided the green roof waterproofing membrane for Australia’s largest desalination plant as a part of a Victorian Government’s soon to be completed construction project.

Sika Sarnafil roofing system

The green roof is the largest of its kind in the southern hemisphere and forms an important part of the project's landscape architecture. Providing acoustic protection, corrosion resistance, thermal control and reduced maintenance, the roof utilizes the Sika Sarnafil system which creates a waterproof barrier for the lightweight, structural ply substrate.

Integration into the environment

The thin profile green roof incorporates patterns using a rich tapestry of indigenous vegetation tolerant of high heat, salt drift, drought and wind. The desalination plant required a design which made the structure barely visible from all public viewing points.

The green roof helps to integrate the building into the environment and enables the continued bio-diversity of the site in its regeneration, acoustic moderation and storm water management.

“The waterproofing membrane had to allow for potential movement from kilometres of joints, for which the Sika Sarnafil ‘G series’ polymeric sheet is ideally suited,” said Geoff Heard of Fytogreen, the green roof builder and designer.

“UV resistance was also required for a 25 year life span. And compatibility with the electronic ILD (international leak detection) system was paramount to enable quality checks to occur prior to Sika’s handover to Fytogreen and after Fytogreen had completed its construction.

Thermoplastic membrane

Faulty seams are a common source of leaks in green roofs. Some waterproofing membranes use sealants, adhesives or tapes to secure the seams. Sika Sarnafil’s membrane is thermoplastic, meaning seams and flashings are welded together using Sika Sarnafil’s automatic hot-air welder.

“Modern techniques for leak detection and high quality membranes like Sarnafil significantly reduce the perceived risk associated with green roofs,” added Heard.

“Adherence to a well-honed green roof construction method and ITP check procedure enabled 26,000 square metres of green roof to be installed without one breach of the membrane during the roof garden installation phase, a testament to the membrane quality and Fytogreen’s attention to detail.”

Ongoing protection to the structure

The waterproofing membrane will provide ongoing protection to the structure from the intensely damp environment, allowing for ongoing irrigation and resistance to root penetration.