Deteriorating Asbestos Roofs – the risk above us

Contaminated mulch received plenty of media attention earlier this year, but it has emerged that there is a far bigger asbestos problem hiding in plain sight. From the 1950s–70s, asbestos was widely used as roofing in Australia and this material was created to have a lifespan of 25 years. This makes most of the asbestos roofs over 40 years old, well past their usable life, and they now pose a significant risk to the community’s health.

John Batty, Managing Director of EDP Consultants, an RSK Group company, has 18 years’ experience working in asbestos and hazardous materials management in Australia, the UK, Europe and North Africa. He is a member of the Asbestos Education Committee and National Asbestos Awareness Campaign and founding member and former president of the Asbestos and Hazardous Materials Consultants Association. He recently spoke at the Asbestos & Hazardous Materials Management Conference in New South Wales and discussed new initiatives to improve hazardous materials management within the built and natural environment.

The Asbestos and Silica Safety and Eradication Agency (ASSEA) undertook a heatmap study to understand the extent of asbestos roofs used in Australia and determined that more than 2 per cent of the dwellings in the country have asbestos roofs installed.

John said: “Exposure to weather and UV radiation has degraded the cement matrix, which allows the fibres to be released. Additionally, storms, rain and hail impact on these materials and degrade the roofs further.”

ASSEA’s survey indicated the presence of 23,000 tonnes of asbestos containing material in Australia and these products are undergoing continuous degradation, with much of it transforming from stable non-friable fibre cement to friable asbestos dust.

John said: “As Australia regularly experiences extremes of weather, any natural disasters would not only significantly damage these roofs but would degrade them to the point where they become friable, posing a higher risk of asbestos exposure and contaminating the building fabric and contents, causing a significant cost blowout for the clean-up effort. The asbestos fibres can be released into the air, into waterways, and also adhere to the exterior and interior fabric of buildings, resulting in an impact well beyond the roofs.”

John points to the fire that engulfed the woolshed at the NSW Newcastle suburb of Wickham in March 2022. As 100 firefighters battled to control the blaze, a particular concern was the structure’s asbestos roof. “The fire caused the asbestos roof to explode, and the contamination was carried by wind currents, spreading 3.2 km from that woolshed. In such cases, remediation is a long and costly exercise as it often requires removal of the structure, decontamination of the surrounding areas and monitoring of nearby waterways.”

Another area of concern is the decreasing awareness of asbestos risks, particularly concerning the high-water-pressure method of cleaning roofs, a practice prohibited under the Work, Health and Safety (WHS) Regulations. “With the new generation of local and migrant workers, there is a lower awareness of correct asbestos handling. This cleaning practice can cause significant damage to roofs, lead to significant contamination to the environment and adversely affect the health of the workers and people in the vicinity,” says John.

Incorrect handling of asbestos products can lead to a massive clean-up bill at the end and John is encouraging property owners first to inspect and then to consider the planned removal and replacement of their asbestos roofs. “A planned removal typically costs between $20,000 and $100,000, whereas an emergency remediation would cost anywhere between $100,000 and a million dollars,” explains John.

Although the importation and use of asbestos as a building material was banned in 2003, legacy structures continue to deteriorate, fuelled by the weather and environmental damage. Until asbestos was banned, Australia was one of the highest per capita users of the material in the world. According to ASSEA, more than 4000 people still die from asbestos-related disease in Australia every year, a number that is triple the annual national road toll. The World Health Organization estimates that one in every three deaths from occupational cancer is caused by asbestos.

“It’s crucial for us to focus on asbestos-related building materials that are exposed to weathering – because their condition can worsen significantly over time, heightening the potential risk to public health,” says John.