On July 2, pedestrians on a street in the inner northern Melbourne suburb of Carlton were shocked when glass shattered and fell only metres from them after an apartment balcony exploded without warning – the second such collapse which had happened at the complex in a matter of weeks.

A similar event happened in Brunswick last year.

Whilst cladding has taken most of the attention following the Grenfell tragedy, issues associated with other products such as glass which fail to meet standards required under the National Construction Code pose a serious threat to public safety.

Sahil Bhasin, national general manager of property consultancy company Roscon, says one factor behind what appears to be a growing incidence of importation of non-conforming products revolves around the growing number of players which operate in the mid-tier building sector who have complete supply chains set up from overseas countries such as China. Whilst not intentionally cutting corners, Bhasin says many of these players choose to purchase from the cheapest supplier, who in turn has cut corners in order to reduce costs – often producing fake certificates of compliance in the process.

Where this raises concerns with glass, he says, is in the heat soaking process which attempts to eliminate any nickel sulphide inclusions in the glass which can cause fragmentation. Because it is not possible to independently test that heat soaking has been done after the fact, Bhasin says this is a common area where low cost overseas manufacturers will seek to cut costs. This is especially the case as heat soaking is costly process (the glass has to be put through a furnace, often at a separate plant to which the glass has to be transported, which has to be at the optimum temperature).

When heat soaking is not performed, Bhasin said spontaneous explosions can occur if sudden thermal temperature changes cause the nickel sulphide to react.

As well as endangering the public, Bhasin says faulty glass can lead to disproportionate costs associated with repairs. When glass shatters in a shower screen, for example, he says you need to essentially strip back the entire bathroom to allow for the waterproofing membrane to be redone throughout the whole room – resulting in a $25,000 bathroom repair bill for what was a piece of glass worth only hundreds of dollars.

Beyond heat soaking, Australian Windows Association chief executive officer Tracey Gramlick says other problems can occur. Damage to the edge of the glass whilst it is being handled or installed can have a ripple effect and lead to breakage, she said. Further problems can arise, meanwhile, where the thicknesses are not calculated correctly according to the requirements of the NCC in respect of load which the building is expected to handle in terms of wind and other things – a situation she says could lead to glass being used which was not sufficiently thick for the situation and people falling back through the glass when inadvertently falling or leading against it.

Gramlick says even a small problem with the glass can cause serious injury if impacted at its weak point. In a recent case, a four-year-old Perth boy suffered lacerations after glass which had been installed in the shower recess approximately eighteen months earlier exploded.

Bhasin says the absence of any ability to test for nickel sulphide means the best way to ensure that heat soaking has been done is to put a qualified person from Australia on the ground to visually verify the process as it is being completed – a cost he says pales into insignificance compared with either overall construction costs for a large apartment building or that of rectifying problems which do occur. As an alternative, builders could use CCTV to monitor the heat soaking process remotely from Australia.

For consumers, Gramlick advises using accredited glaziers and asking for evidence that the product meets applicable NCC standards.

She says glass can cause serious injury and/or fatality, and that there was no guarantee that even toughened glass or safety glass will be free from defects.

Finally, Gramlick expressed frustration that excessive levels of attention have been afforded to one or two singular products (cladding and electric cables) in terms of non-compliance and that focus has shifted away from the broader issue of non-complying product toward a narrower one revolving around cladding and cables.

“What tends to happen is that we get a little bit of traction and people talk about the diversity and the vastness of issues about non-complying products and non-conforming products,” she said. “And then it seems to be that because they (cladding and cables) are often dramatic or could be fatal that all the focus and attention goes on to one product.

“We’ve been talking about this problem (non-conforming products) for years. We finally got traction through the Building Ministers Forum and there were a lot of people doing a lot of work.

“All of a sudden, you get these two significant issues (cladding and cables) and they deflect attention from the greater need to think of the building as a whole and not just one particular product.”