Asbestos in Homes: Identification and Management

For much of the 20th century, asbestos was considered a miracle material. It was fireproof, durable, an excellent insulator, and cheap to produce. These properties made it incredibly popular in construction, and New Zealand homes built between the 1940s and 1980s often contain asbestos in multiple locations. The health risks were not widely understood until later, and by then, asbestos had been incorporated into countless buildings across the country.

If your home was built before 1990, there is a reasonable chance it contains some asbestos-containing materials. This is not cause for panic, but it is cause for awareness. Understanding where asbestos might be, when it poses a risk, and how to manage it safely can protect your family's health and help you make informed decisions about renovations and maintenance.

Where Asbestos Might Be in Your Home

Asbestos was used in a remarkable variety of building products. Some of these were structural components that remain hidden within walls and ceilings. Others were surface finishes that you might see and touch regularly without realising what they contain.

The widespread use of asbestos means that renovation work on older homes almost always carries some risk of encountering asbestos-containing materials. This is why testing before disturbing any suspect materials is so important.

Understanding the Risk

Asbestos fibres cause serious diseases including asbestosis, lung cancer, and mesothelioma. However, the mere presence of asbestos in your home does not mean you are at risk. Asbestos becomes dangerous only when microscopic fibres are released into the air and inhaled. This typically happens when asbestos-containing materials are damaged, deteriorate with age, or are disturbed during renovation or demolition work.

An intact asbestos cement roof in good condition poses minimal risk to occupants because the fibres are firmly bound within the cement matrix. The same roof after 50 years of weathering, with cracking and surface deterioration, poses a much higher risk. And that roof being removed by someone without proper training and equipment poses the highest risk of all.

Testing and Identification

You cannot identify asbestos by looking at it. Many materials that look like asbestos do not contain it, and many that look harmless do. The only reliable way to know whether a material contains asbestos is laboratory testing.

Testing involves collecting a small sample of the suspect material and sending it to an accredited laboratory for analysis. This sounds simple, but sampling itself can release fibres if not done properly. For this reason, it is generally safer to have samples collected by professionals rather than attempting it yourself.

If you are planning renovations, a pre-renovation asbestos survey by a qualified assessor is the safest approach. They will identify all materials that might contain asbestos, collect samples for testing, and provide a report detailing what is present and recommendations for management. This survey typically costs a few hundred dollars but provides essential information for planning your project safely.

Management Options

When asbestos is confirmed in your home, you have several options. The right choice depends on the type and condition of the material, your renovation plans, and your tolerance for ongoing management.

Encapsulation involves coating asbestos-containing materials with a special sealant that binds the surface and prevents fibre release. This can extend the safe life of deteriorating materials and is less expensive than removal. However, encapsulation is not a permanent solution and the material will eventually need to be addressed.

Removal is sometimes necessary, particularly when materials are badly damaged, when renovation work requires their disturbance, or when you simply want them gone. All asbestos removal must be done by licensed removalists following strict procedures designed to protect workers and prevent environmental contamination.

The Removal Process

Licensed asbestos removalists follow detailed procedures to minimise fibre release and exposure. For significant quantities of friable asbestos, this includes constructing sealed enclosures with negative air pressure, wearing full respiratory protection and disposable suits, keeping materials wet to suppress dust, and disposing of waste at approved facilities.

Removal of bonded asbestos like cement sheets follows less stringent but still careful procedures. The work area is isolated, materials are removed intact where possible rather than broken up, and all waste is double-bagged and labelled before disposal.

Costs for asbestos removal vary significantly depending on the type and quantity of material. Removing a small area of cement sheeting might cost a few hundred dollars. Removing an entire asbestos cement roof could cost $10,000 to $20,000 or more. Friable asbestos removal is the most expensive due to the stringent safety requirements.

Planning Renovations

If you are planning renovations on a home that might contain asbestos, build testing and potential removal into your project timeline and budget from the start. Discovering asbestos mid-project creates delays, additional costs, and safety risks that proper planning would have avoided.

Before work begins, have suspect materials tested. If asbestos is present in areas that will be disturbed, arrange for professional removal. Ensure your building consent application addresses asbestos management if required. Only then should physical work commence. Taking this methodical approach protects everyone involved and prevents the costly complications that arise from encountering unexpected asbestos during construction.