Tirau is a small junction town in the Waikato,
lying near the intersection of State Highway One with two other highways. More recently
it has become known as New Zealand’s corrugated iron capital, thanks to a number of corrugated
iron structures in the town. Originally the site of a military garrison,
Tirau became a farming town and a stopping point for travellers. However, by the late
1980s, a rural downturn meant that, like many small farming towns in New Zealand, Tirau
was dying. Enterprising local businesspeople exploited Tirau’s location as a junction town
to open antique and craft shops. These attracted travellers and boosted the local economy. Building on this success, locals looked for
something else that would set Tirau apart and attract visitors. They found it with corrugated
iron — and constructed a number of large corrugated iron structures and sculptures.
These included a big dog, which houses the town’s information centre, and a big sheep
which houses a wool gallery. The local church has a large shepherd outside, also made out
of corrugated iron. Corrugated iron is a light steel sheet that
has been galvanised — treated with a coating of zinc — to prevent rusting, then rolled
into corrugations. First produced in English steel mills in the 1830s, it was regarded
as suitable only for temporary buildings. In the New Zealand goldfields of the nineteenth
century, there was a need for speedy construction. Corrugated iron was the perfect material as
it was weatherproof, light, portable, and easy to put up.
A company in Dunedin was the first to produced corrugated iron, which they did in 1864 from
imported steel plate. As the New Zealand population became settled, more permanent buildings were
built. Corrugated iron was only used for those parts not immediately visible. Many houses
and commercial buildings had wooden or stone frontages, but the sides and back that no
one saw were often made from corrugated iron. Such a style was described as ‘Queen Anne
in the front, and a meat safe at the back’. Corrugated iron was widely used in rural areas.
Farmers could readily build a frame for a shed or hay barn themselves, and then clad
it with corrugated iron. Because the sheets of iron had to be purchased and then transported
to the farm, they were often re-used once a temporary building was abandoned.
From the early twentieth century, corrugated iron was mainly used as a roofing material
— often painted red or green. Many immigrants recorded their surprise at seeing the colourful
iron roofs when they first arrived in New Zealand. But when the 1935 Labour government
started a programme of house construction, they discouraged the use of imported components,
so tiles and other roofing materials gradually replaced corrugated iron.
However in the 1970s, New Zealand Steel started to produce a variety of corrugated products
that have been widely used for roofing. And in the 1990s, these reappeared as a cladding
material, as part of a local architectural style based on functionalism and nostalgia.
Because it is flexible and readily shaped, corrugated iron has also enjoyed a renaissance
as a material for modern sculpture. Today, corrugated iron sometimes clads entire
buildings, with recent examples being Wellington’s Westpac Stadium, nicknamed the Cake Tin. Writer Janet Frame wrote a poem — rain on
the roof — about the nostalgia for the sound of rain falling on a corrugated iron roof.