How to test for asbestos before starting DIY on your property

Amy Hamilton-Chadwick
How to test for asbestos before starting DIY on your property
It's estimated that 40,000 homes in Canterbury alone contain asbestos.

Before you start that DIY project, take a second look at what you’re about to tear down.

If you rip into asbestos, you could be putting yourself in harm’s way.

It’s not known how many Kiwi houses contain asbestos, but with an estimated 40,000 affected homes in Canterbury alone, the number is likely to be in the hundreds of thousands.

“Asbestos was an amazing product. It’s fire resistant and hardy in corrosive sea air which was great in New Zealand,” explains Robert Birse, principal advisor – asbestos at Worksafe.

“Unfortunately, we now know that exposure to its fibres can lead to a serious health risk.”

Inhaled asbestos fibres can cause illness and cancer; you are not permitted to manufacture or import products containing asbestos.

However, during the period between 1940 and 2000 (and especially between the 60s and the mid-80s), more than 3000 different products containing asbestos were used in New Zealand homes.

The most common places to find asbestos in your home are:

  •     Textured ceilings.
  •     Flooring, often the backing on vinyl floors.
  •     Cement cladding, water pipes and roofing.
  •     Lagging around hot water cylinders.
  •     ‘Fibrolite’ or ‘fibro’ cladding, a brand of asbestos cement panels often found on garages.


While asbestos has real risks, if the products are undamaged, in a stable condition and left untouched, they’re generally safe.

It’s when you begin to cut into the products or remove them that the fibres can be released.

“Before you buy any house, especially those built before the year 2000, or start renovating your own house, find out whether you’ve got asbestos,” says Birse.

“The old Hardie sheets [Fibrolite] could contain 12% to 14% asbestos by volume, whereas the lagging around your hot water pipes and the backing under your old lino could be as high as 90%.

The only way to be certain is to have your products tested. Take a small sample, wet it, double zip-lock bag it and take it to a lab. It costs about $90, and it could be the best $90 you ever spend.”

Birse says there’s still a lack of understanding about asbestos among both tradespeople and the general public – cash-strapped first-home buyers often take the ‘demolish first, ask questions later’ approach to renovating their houses.

He has heard stories about people ripping up old lino from a bathroom or kitchen without realising it contains asbestos.

“Every time they rip the backing board, they could be exposing themselves to thousands of fibres that are released into the atmosphere – lino is a significant risk to DIYers.

Textured ceilings are another risk area if people start to remove it without having it tested first.”

It is legal to remove asbestos from your own home, although the Ministry of Health strongly recommends you ask a professional to do the job; ask around to get several quotes.

“Information is what you need,” says Birse.

“Before you start any work, know what you’re doing and understand the risks so you can make an informed decision.”

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