Asbestos testing

Does your house contain asbestos?

I am trained in asbestos removal (I can legally remove up to 10 square metres), I am careful, aware and cautious. As a licensed contractor, under SafeWork legislation, I am required to be.

I was recently asked to carry out some renovations on several bathrooms. I raised the likelihood of the rooms containing asbestos with the owners. I carried out some tests, and 3 of the 4 samples returned positive.

I wanted to discuss the results here because one of the tests surprised but also disappointed me. It highlights why caution needs to be taken with building materials, but particularly cement sheet products at all times.

How do you determine whether something does, or doesn’t contain asbestos?

Testing – this is the only guaranteed method of verification that your product does or does not contain asbestos. Yep, you can tap it, listen, look, feel…. But none of it matters one bit if you don’t have a test report.

If you are drilling, altering, demolishing cement sheet (or other building material that has historically contained asbestos) in a home built before the year 2000, you should treat the building material as if it does contain asbestos – unless you can demonstrate otherwise through labelling, previous testing, or some other guarantee.

See for a list of building materials that could contain asbestos.

Some good images can be found at

As a general rules:

  1. Anything built before 1984 is certain to have asbestos (some of these houses are clad with metal of vinyl cladding over the top of the asbestos sheet)
  2. Built between 84 and 2000 it could have asbestos in it – and care should be taken. (in my opinion, anything between 1980 and 1990)
  3. Built after 2000 it shouldn’t, but it is possible (home owners sometimes use second hand materials, and some asbestos has been known to come into the country since 2000, as different countries have different criteria).


I note above “labelling”. I have come across some products that were able to be identified as positive or negative through product labelling. Where a product code, model number, batch number can be identified via the manufacturer that is a suitable method of verification. I have verified both positive and negative samples in this manner. Labelling would need to be documented, and report from a manufacturer showing batch numbers would have to be provided to SafeWork or disposal company should it be requested.

So the results and why I was surprised by one sample.

The home is a late 1960s build, with an early 1970s extension. The eaves, bathroom and laundry were expected to contain asbestos and the results were positive for both Chrysotile (white) asbestos and Crocidolite (blue) asbestos.

When I took a sample from the kitchen, I felt that the fibro was too soft to be asbestos. On this occasion I was correct, however I have been caught out before. In this instance it was negative.

The fourth sample is the one that caught me off guard. The upstairs bathroom was recently renovated with new tiles on the floor and walls, new shower and vanity. The sample was thick >6mm, but hard. Because the bathroom was recently renovated, I believed that any asbestos would have been removed. Sadly I was incorrect, and the sample was positive for Chrysotile (white) asbestos.

I would have expected any renovation of a wet area, to also have removed all asbestos. However this sample was positive, meaning that asbestos wasn’t removed during the previous renovation. This is concerning, because it means that the contractors who renovated that bathroom would have exposed themselves, and all occupants to asbestos during that renovation.

This is very disappointing to find, because all contractors should be aware of asbestos in building materials. Even removing tiles off a wall of an asbestos bathroom causes fibres to be released and exposes those removing them. It also means that everyone in the house at the time (and afterwards) would have been exposed to those fibres.

So why did I check these areas of the house?

I always presume that fibro contains asbestos, unless the building is guaranteed to have been build after the year 2000. I am still careful.

If I am going to do any major work on a home that is likely to contain asbestos, I have it tested. If the sample is negative, the job is then cheaper, if it is positive, I know that I have to take particular care – simple!

I have been caught out before. Several times now I believed that a soft fibro sample would not contain asbestos, but results have come back positive. I have therefore learned that there are no guarantees, and to suspect asbestos and test everything.


One area of a home that I am often exposed to that contains asbestos is switchboards. Most houses built before 1990 contain asbestos. The black panels are more easy to distinguish if they are likely to contain asbestos, and care needs to be taken.

Repairs, alterations and renovations

Drilling, cutting, altering asbestos relating materials releases fibres and may expose the worker or others to those fibres. While one fibre may not cause disease, it is equally possible that one fibre may cause disease! You can’t take the risk.

I don’t take risks with your health and safety. I work on asbestos containing materials (ACM), or products that could contain asbestos, with care. It is more time consuming, and more costly, but it’s also a legal obligation.

If you care about your health and the welfare of your family, don’t let your contractor take risks with your safety.

Please remember: Your contractor is not allowed to drill, cut, disturb or alter building material that contains asbestos (or could contain asbestos) without doing it in an asbestos safe manner.

If they are drilling a small hole, they should avoid it where possible, but if it is necessary, do it in an approved manner.

If you are doing renovations, get your contractor (or another qualified individual) to carry out tests and make sure that you get a copy of the “Chain of Custody” form and laboratory test results.

All tests must be undertaken by a NATA accredited laboratory, and the test reports including the Chain of Custody documents (which should be kept together) are considered legal documents. If you are at all concerned, get a second opinion.

Stay safe.


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