How to deal with the problem of asbestos in Australia is something authorities have grappled with for decades.
Across the country, thousands of homes built in asbestos’ heyday are still standing. Most contain varying amounts of the deadly mineral — predominantly in the form of fiber-cement sheeting.
Types of sheeting commonly found in older Australian homes include:
Corrugated Asbestos Sheets: Used in roofing and siding of all types of buildings including homes, factories and farms.
Asbestos Flat Sheet: Used as walls in home interiors and flooring underlay.
Asbestos Lumber and Cement Sheathing: Used as a base for roofing, shingles and false-brick facing.
Ticking Time Bombs
The majority of these older homes are occupied, raising serious concerns for residents.
Why? Because the cement holding the asbestos fibers in place within wall sheeting and corrugated roofing panels has reached the end of its working life and is now vulnerable.
Roofing, in commercial and residential buildings, is of particular concern because its exposure to the elements and the likelihood of it becoming friable.
The term friable refers to any asbestos-containing material that can be easily crumbled, pulverized or reduced to powder when damaged by exposure to weather, fire or human intervention such as home renovations and vandalism.
When this happens, deadly asbestos fibers — no longer contained within the cement — are released into the air. Once inhaled, they can cause long-term damage to the lungs, resulting in diseases such as asbestosis, lung cancer and mesothelioma.
Asbestos Abatement in Australia
Contrary to popular belief, the term “asbestos abatement” does not refer to the removal and disposal of asbestos-containing materials alone, but to a decrease in and lessening of the dangers and hazards associated with these products.
Accordingly, there are different methods of asbestos abatement: Demolition, removal, encapsulation, encasement and enclosure.
Total demolition of homes with asbestos-containing materials is a complex and lengthy process with associated costs between $6 and $18 or more per square foot, depending on the complexity of the job.
Demolition also comes with serious health risks for anyone involved in the operation because of the possibility airborne asbestos fibers. Because there are so many older homes containing asbestos materials across Australia, demolition alone is not considered to be a practical or feasible option.
This process involves the removal of asbestos-containing materials only, leaving the rest of the house or building intact. Regardless, it can be a time-consuming and expensive process, costing between $6 to $12 dollars per square foot, depending on the complexity of the job.
Factors associated with these costs include finding temporary accommodation for residents, rebuilding or repairing affected homes, and transportation of removed asbestos to a safe facility. This method also comes with serious health risks because of the possibility of airborne asbestos.
Encapsulation involves covering asbestos-containing materials with a seamless protective coating. It is effective in eradicating the need to dispose hazardous material and is conceivably the safest and most cost-effective method of asbestos management.
The encapsulant — a thin liquid with penetrating, bridging and hard setting qualities — is mixed with 50 percent water and sprayed directly onto the surface of asbestos containing materials, effectively preventing any release of asbestos fibers.
Otherwise known as “spray-applied enclosure,” encasement is similar to encapsulation in its application and benefits, however there are a number of differences that make this a long-term solution.
The water-based spray is thicker and possesses elastomeric properties that allow for mechanical fasteners to be adhered to the surface.
The spray is applied in amounts varying from 7 to 40 mils, depending on a number of factors, including: surface conditions, intended use of the building and desired warranty.
Once applied, the outer shell of the encasement is highly resistant to damage from accidental or deliberate impact, heat, water, acids, ultra-violate light and mechanical and seismic occurrences.
Enclosure, typically involving the placement of Gypsum board or plywood around asbestos-containing materials, protects the installer and home occupants from direct contact with asbestos-containing materials.
It does not however guard against indirect contact through the release of asbestos fibers and is seen as a short-term remedy prior encapsulation or removal. Since most Australian states require encapsulation prior to enclosure, it is not cost effective.
No Easy Solution
Because of the magnitude of the asbestos problem in Australia, there is no easy solution. To be effective, all abatement methods may need to be utilized, separately or in unison depending on the circumstances.
Although asbestos-encapsulation products are now available on the market, consumers are advised not to apply it themselves.
The encapsulation process should instead be carried out by a professional contractor in controlled conditions and in accordance with the latest industry rules and regulations concerning asbestos materials.
Regular checks to evaluate the condition of the sprayed asbestos material over time should also be implemented.