A corrugated tin roof is perhaps the quintessential sign of an Australian home. While a common construction material in rural areas in the United States, Chile, New Zealand and later India, no country has taken to corrugated iron in the same way Australia has.
A corrugated tin roof is perhaps the quintessential sign of an Australian home. While a common construction material in rural areas in the United States, Chile, New Zealand and later India, no country has taken to corrugated iron in the same way Australia has. Australia is, without a doubt, the spiritual home of corrugated roofing.
Corrugated roofing was invented by the British architect and engineer Henry Palmer, who worked for the London Dock Company. It was originally known as CGI, which stood for corrugated wrought iron. In its earliest form, CGI exhibited strength, corrosion resistance and convenient transportation, all of which led to its desirability in the production of prefabricated structures by skilled workers. Composed of sheets of hot-dipped galvanised iron, it was cold-rolled to produce a linear corrugated pattern – a series of alternating grooves and ridges for weather resistance and increased strength.
Mostly used for commercial and industrial purposes, it wasn’t until around the 1880s when Australia adopted corrugated roofing as part of their attractive architecture that it became a cultural identity and Australia’s most iconic building material.
The gold rush in Victoria was the major catalyst for this, demanding material that was speedy in its construction, flexible, lightweight, cheap and well-suited to the Australian environment. Used as roofing for verandahs and in the form of portable shops, it was soon used to make vast numbers of prefabricated dwellings to house colonial settlers, miners and other workers.
Australia’s iconic tin roof
For the opening ceremony of the Sydney Olympics, John Frohlich and Ian Copper were commissioned to compose The Tin Symphony – a seven-minute extravaganza described by American television networks as a “celebration of Australia’s larrikinism”.
The Tin Symphony sequence included the largest number of Australian icons and at the centre of it all was the tin roof – “the building material that made the bush”.
The tin roof (corrugated iron) did indeed play a strong role in the settling of Australia. As a material of the industrial and colonising age, it has been a crucial part of our frontier and mining adventures. We associate it with distinctively Australian buildings such as “the Queenslander”, the shearing shed, the woolshed, the outdoor dunny and the ubiquitous water tank that’s essential to Australia’s development and survival.
What sparked the fascination?
When galvanised corrugated iron first arrived in Australia in the 1850s, the benefits were clear early on. It was easily and swiftly applied, light, compact, inexpensive, fireproof and immune from insect attack. Enough iron to cover the roof of a cottage fitted easily onto a dray or cart, making a load that was light enough to be dragged over bumpy roads to almost any bush building site.
The terms ‘corrugated iron’ or ‘galvanised iron’ became misnomers after about 1915 when steel began to replace iron in the manufacturing process. The change went unnoticed by the general public, but today, with increased use of Zincalume (an alloy of zinc and aluminium) the old term is fading.
The tin roof today
While galvanised corrugated roofing has its benefits, one look at a building that used roofing sheets manufactured before 1960 will tell you that galvanised corrugated iron or steel rusts. Corrugated roofing starts to degrade within a few years despite the protective action of the zinc coating and marine and salty environments speed up this process even more so because of the high electrical conductivity of seawater.
To get past this, changes have been made to steel production. Companies such as Australia’s highly respected Bluescope Steel have been testing in Australia’s harshest conditions for the last 50 years and today, Colorbond steel offers:
Thermatech solar reflectance technology for greater insulation without the cost
A range of 20 colours to suit the local landscape and style of the house
Flexible building design
Durable roofing, fencing, guttering and walling that offers security against heavy storms and hail
One of the most recycled materials on Earth
A complete warranty
And most importantly – a leading metallic coating that ensures outstanding anti-corrosion performance. In other words, you get all the benefits of the tin roof, without the rust.
The popularity of tin roofs today
Due to the Australian weather, metal roofing remains one of the most popular roofing options for modern homes. Capable of withstanding the country’s climate while still providing homeowners with sufficient protection and comfort against the elements, it’s little wonder that so many builders love this material.
Metal roofing is affordable, durable and thermally efficient. Colorbond steel is currently the standard metal roofing for many Australian homes and is meant to last for 100 years with proper maintenance.
Other metal roofing options include:
Zinc plated steel
Sea Side Grate steel
Stainless Steel Colorbond
While Australians also have the option of using tiled roofing, many choose the considerable advantages of metal over tiles. These advantages include:
Easier and faster to install
More durable when taken care of
The ability to cool down quickly during hot summer months and retain heat during cold winters
More cost-efficient both during initial installation and throughout its life
Resistance to hail