A deteriorating surface of corrugated asbestos cement roof cladding with asbestos debris in the gutter.

One of the most common areas to find asbestos in your home is the roof. It’s also one of the most dangerous, because of its constant exposure to extreme weather conditions (sun, hail and strong winds), which can damage the asbestos-containing materials and result in harmful asbestos fibres becoming airborne.

Most people are familiar with the “fibro roof”, which is usually found as corrugated sheet, trimmed or cut into various styles and widths to suit the house design. However, asbestos roofing can also be flat, profiled or imitation slate tiles. Skylights, ventilators and ridge/edge capping can also be formed or shaped using asbestos cement.

A special asbestos coating was sometimes applied to corrugated iron or profiled iron sheets, and was also used as roof or wall cladding – particularly in coastal areas – as protection against corrosion. This is commonly known as “galbestos”.

If you suspect your roof may contain asbestos, it’s important to regularly monitor its condition. Not only can fibres become airborne, but they can also contaminate your drinking water. If you have an asbestos cement roof, we strongly recommend you do not collect the rainwater for usage in or around the home. Over time, as the cement erodes, the asbestos is released and washed down your roof into your gutters and down your drains.

To check whether your asbestos roof needs replacing, check your gutters for bits of the roof containing fibres or hanging “dags” of asbestos at the ends of the corrugations. Other signs that the roof needs replacing include exposed fibre, water leaks or obvious water stain marks.

Never remove asbestos yourself. We strongly urge you to consult with an expert and get an asbestos audit or asbestos survey done on the building if you believe your roof contains asbestos and needs replacing. It is possible to seal unpainted/unsealed asbestos roof cladding, but this depends on the condition and level of deterioration.

For more information and images of asbestos roofing, get a copy of our book Identifying Asbestos in your Home.