Melbourne has an extraordinary density of pre-1987 housing stock. Victorian terraces, Edwardian bungalows, inter-war bungalows, and the vast suburban expansion of the 1950s through 1970s collectively represent hundreds of thousands of homes that may contain asbestos-containing materials (ACMs). For homes with ducted heating systems installed before the Australian asbestos ban of 1987, the ductwork itself — specifically duct insulation, duct tape, and plenum components — may contain asbestos.
This guide covers what asbestos materials were used in Australian ductwork, how to assess risk in a Melbourne home, what must happen before any duct cleaning or maintenance work proceeds, and the regulatory framework for asbestos management in Victoria.
Asbestos in Australian Ductwork: What Was Used and Where
Asbestos was used extensively in Australian building materials from the 1950s through to its gradual phase-out in the 1980s. In ducted systems, it appeared in the following components:
Duct insulation wrap
Flexible duct runs installed before the mid-1980s were sometimes wrapped in an asbestos-containing insulation material — appearing as a grey-brown fibrous blanket around the outside of the duct. In Melbourne’s older housing stock, this insulation is commonly found in roof spaces where original ducted heating was installed in the 1960s through 1980s. Over time, the insulation wrap deteriorates and can become friable (crumbling), releasing fibres into the roof space and potentially into the duct system through deteriorated duct joints.
Duct tape
An asbestos-containing tape was used to seal duct joints in some installations before the 1980s. This tape is typically dark grey or off-white and has a fibrous, woven appearance. Unlike modern metallic duct tape, asbestos duct tape becomes brittle and crumbles with age — a particularly hazardous characteristic since it can release fibres when disturbed during maintenance or cleaning.
Plenum components
The plenum — the main air distribution box attached to the heater unit — in some older Melbourne systems was constructed from or lined with asbestos-containing board. This is most common in systems installed in the 1960s and 1970s. Plenum ACMs are typically less accessible and less likely to be disturbed in routine maintenance, but they are the most serious ACM in a ducted system if they deteriorate.
System unit casing and insulation
In some older heater units, the casing or internal insulation of the system unit itself may contain asbestos. This is relevant when the system unit is being replaced or substantially modified — the replacement work must account for potential ACMs in the old unit.
Assessing Risk in Your Melbourne Home
The first step is identifying whether your Melbourne home is in the risk category and, if so, confirming whether ACMs are present through professional assessment.
Is your home in the risk category?
Built before 1975: High risk. Asbestos was in common use in all building trades including HVAC. If the original ducted system is still installed, there is significant likelihood of ACMs in duct insulation, tape, or plenum components.
Built 1975 to 1987: Moderate risk. Asbestos use was declining but not prohibited. Systems installed during this period may still have ACMs, particularly in older remaining duct sections or systems that were not fully replaced.
Built 1987 to 1990: Low risk. The use of ACMs in new construction was largely discontinued, but existing materials in renovated or partially updated homes may still be present.
Built after 1990: Minimal risk. Asbestos was effectively absent from new construction materials after 1990, and Australia’s full asbestos import ban came into effect in 2003.
Engaging a licensed asbestos assessor
If your home is in the risk category, engage a licensed asbestos assessor before any duct maintenance, cleaning, or inspection work is undertaken. The assessor will identify accessible ACMs, assess their condition (intact vs. friable), take samples for laboratory confirmation, and provide a report documenting ACM locations and risk level. This report is the prerequisite for any duct cleaning company to assess whether and how cleaning can proceed safely.
Duct Cleaning in Melbourne Homes with Potential ACMs
FreshDuct does not perform duct cleaning work in pre-1987 Melbourne homes without confirmation of asbestos status. Before booking any duct cleaning service for a pre-1987 property:
Option 1: Assessor confirms no ACMs
If a licensed assessor confirms that no ACMs are present in the duct system and surrounding areas that could be disturbed by cleaning work, standard duct cleaning can proceed normally. The assessor’s report provides the clearance needed.
Option 2: ACMs are confirmed but intact and undisturbed
If ACMs are present but in good condition (not friable, not releasing fibres), the assessor may confirm that cleaning of the duct interior can proceed with appropriate precautions. The cleaning process must not disturb the ACMs. This is assessed case by case depending on ACM location and condition.
Option 3: ACMs are friable or damaged
Friable or damaged ACMs must be remediated by a licensed asbestos removalist before any duct cleaning or maintenance work proceeds. Duct cleaning of a system with friable asbestos materials would release fibres into the duct system and potentially throughout the home.
Victorian Regulatory Framework for Residential Asbestos
In Victoria, the management of asbestos in residential properties is governed by the Occupational Health and Safety Act 2004, the OHS Regulations 2017, and specific WorkSafe guidance for residential work. Key points for Melbourne homeowners:
Any person carrying out work that is likely to disturb asbestos must take all reasonably practicable steps to manage the risk. For residential properties, this means identifying ACMs before work begins, assessing the risk, and implementing appropriate controls.
Friable asbestos removal requires a licensed removalist (Class A licence) for quantities above 10 square metres. Non-friable ACMs under 10 square metres may be removed by unlicensed persons, but professional removal is strongly recommended given the health stakes.
WorkSafe Victoria provides a residential asbestos guidance document available on their website. The Asbestos Safety and Eradication Agency (ASEA) maintains a national directory of licensed asbestos assessors and removalists.