How To Tell The Difference Between Asbestos Fence (And Super Six) And Hardifence

How To Tell The Difference Between Asbestos Fence (And Super Six) And Hardifence

How To Tell The Difference Between Asbestos Fence (And Super Six) And Hardifence


For over 40 years, Australian builders have been using corrugated fibre cement sheets for roofing or fencing. Two specific products for this purpose remain popular: corrugated asbestos Super Six sheets and the more modern non-asbestos Hardifence.

Can you distinguish between the two? If you’re wondering how to tell the difference between asbestos fence (and Super Six) and Hardifence, here are some key points to remember.

First, the basics.

James Hardie & Co. manufactured the original corrugated Super Six asbestos cement sheets in the 1950s. This means that the name “Super Six” is synonymous to the asbestos fence sheets. This product was widely used for roof sheeting and fencing, and it can still be found in various structures that exist to this day. However, production of Super Six ceased in 1985.

After 1985, a replacement for Super Six was developed: Hardifence. Unlike the former which was composed of deadly asbestos fibres, Hardifence is made of safer cellulose fibre which is essentially derived from wood pulp. This friendlier alternative to Super Six is known among builders as an excellent product and is still being manufactured at present.

Next, the key differences.

Count the ridges. Hardifence’s latest version features only 5 ridges, which makes it easy for builders and homeowners to distinguish this asbestos-free product from Super Six, which has 7 ridges. Take note, however, that earlier Hardifence versions had 7 ridges like Super Six, but they are likely to sport breakages, cracks at the bottom, and signs of damage on the diamond washer/nut and bolt fixing.

Check the house’s age. Super Six is most likely to be found only in houses built before the late 1980s, as they would have been installed in the 1960s and 1970s.

Identify the capping material. Fence sheets that are fitted with fibre cement capping are sure to be the kind made with asbestos. The latest Hardifence products come with a metal capping, which is essential for keeping the sheets from separating at the top.

Look for identifying marks. Hardifence will typically have the word “Hardifence” printed on the edge of the sheet, along with the manufacturing date. Earlier versions, on the other hand, will have the words “Manufactured Without Asbestos” and the manufacturing date printed on them.

Take a picture. Using a digital camera in macro mode, snap a photo of a broken corner or edge of the sheet (don’t make a new break, in case of the presence of asbestos). The fibres in an asbestos sheet will stick out in the broken-off point, while the cellulose fibres in Hardifence will look similar to torn cardboard with soft fuzzy edging, due to the fibres being shorter and bonded more uniformly.

Run your fingernail along it. You cannot gouge a mark into asbestos-laden Super Six, but you can with Hardifence; the latter is softer than the former.