At the close of 2018, The Australian newspaper exclusively reported that structural engineers had ruled out any integral weakness in a prefabricated concrete panel as the cause of cracking in the Opal Tower, a residential high-rise in Sydney’s west.
Sarah Bachmann, CEO of the National Precast Concrete Association Australia, told Built Offsite that correct engineering design and installation are both critical factors in ensuring a building’s integrity and reiterated engineers’ findings that the damage was likely the result of the engineering design or construction of the building.
“In instances like these, it would be rare to find the integrity of the precast element at fault,” Bachmann said. “I’d also like to note that all National Precast members have robust quality systems and procedures in place to ensure elements are compliant with Australian standards and are manufactured in accordance with shop drawings approved by an engineer.”
It is understood about 230 of the panels, manufactured by Sydney company Evolution Precast Systems, were installed at Opal Tower, which opened in August 2018, to construct walls around 12 garden areas.
Bachmann confirmed Evolution was not an Association member. “I would say however that it’s a reputable company and I’m confident of the integrity of its offering. The Opal incident is something that could equally apply to any product or construction material. In fact, one of the advantages of precast concrete is that it requires a specific approach in terms of erection design, which gives clients peace of mind. Many other heavy building products do not require the same level of scrutiny.”
“In the case of the Opal Tower, from what we currently know, the building’s engineering design could be the cause and that is currently being investigated.” The Opal Tower incident has highlighted concerns over construction procedures, in particular relating to high-rise buildings, already outlined in more than one report.
Commissioned by the Building Ministers’ Forum, a group consisting of federal, state and territory ministers, the Shergold and Weir report Building Confidence was released in February 2018 and contained 24 recommendations.
Released in light of the 2017 Grenfell Tower fire in the UK that caused 72 deaths, and a similar fire at the Lacrosse building in Melbourne’s Docklands in November 2014, it found reports of “serious compliance failures in recently constructed buildings” including non-compliant cladding, water issues leading to mould, structurally unsound roof construction and problems with fire safety.
The report indicated that compliance and enforcement systems were inadequate accident prevention mechanisms and needed to change “as a matter of priority”.
The senior bureaucrat in charge of reviewing building regulations for the NSW government has also condemned the lack of action on his 2015 report, warning that defects in the Opal Tower were “likely just the tip of the iceberg.”
Former NSW Treasury secretary Michael Lambert, who was commissioned to write the Lambert Report following the Bankstown fire in 2012, indicated that while certification of fire safety systems for high rise buildings was a tangible outcome of his review, the remainder of his almost 150 recommendations had been neglected.■