Colorbond Steel

Colorbond (styled COLORBOND) is the trade name of a range of prepainted, metallic-coated steel made by BlueScope in Australia. It is used for roofing, walling, gutters, fencing and sheds, and is so widespread that "Colorbond" is often used in Australia as a generic word for painted steel roofing. Similar BlueScope products are sold in New Zealand, Southeast Asia and other markets.

History

Corrugated iron reached Australia in the mid-nineteenth century, introduced by John Lysaght, and for nearly a century the only way to colour it was to repaint it regularly. In the 1950s, US companies developed a way to bond paint to a galvanized base, and Lysaght brought the technology to Australia. The first coil of Colorbond steel came off the painting line at Port Kembla, near Wollongong, New South Wales, in 1966.

Construction

BlueScope describes five layers:

1. A steel base made to Australian Standards.
2. A metallic coating using BlueScope's "Activate" technology, which the company says improves corrosion resistance (not offered on some variants, such as those on a galvanized base).
3. A pretreatment layer for adhesion.
4. A baked corrosion-inhibiting primer.
5. A baked exterior-grade topcoat.

The product is made to Australian Standards AS 1397 (metallic-coated steel) and AS/NZS 2728 (prefinished and prepainted products).

Variants

The range includes several product variants for different uses and exposures. BlueScope's unpainted aluminium-zinc coated steel is sold separately as Zincalume.

Context

Colorbond is one of several regional prepainted steel brands; equivalent products exist in North America, Europe and Asia under other names. Its long history and familiarity have made it a reference point in Australian building culture.