From S, Adelaide

Are there any Australian or architects from around the world who like working in new corrugated iron? Answer: Max Pritchard - Adelaide based architect - specializes in corrugated iron modern domestic structures. 2.7.03

From JS, Corus

'Corrugated iron' is produced from at least a dozen different sources in the UK and is commonly 3'' corrugated (or 76mm in new money). The 3'' refers to the distance between the centres of corrugations.

The popularity of galvanised steel corrugated sheets started to wane with the introduction of pre painted 'box' or 'trapezoidal' profiles produced from about 1960. Galvanised corrugated was commonly bitumen coated or painted once erected and the introduction of pre finished coil for rollforming negated this need to physically paint 'on site'. Polyester and pvc paint systems such as 'plastisol' became extremely popular in a relatively short period and soon newly designed box profiles took over from the 3'' corrugated. The 38mm box or 'WA6' as it was known became the most popular roof and wall profile and because of the increased depth and trapezoid shape, the sheet was a lot stronger and could clear span a greater distance. It was at this time that asbestos sheeting started to become redundant and the bad health press linked to asbestos in the late sixties virtually killed off the product.

3'' Galvanised Corrugated continued to be roll formed throughout this period but the market steadily declined to pure agricultural and temporary structures. Pre painted 3'' corrugated (half round 19mm or half inch depth) was and is still used for cladding and some roofing. 3'' corrugated started to become fashionable again recently, laid in horizontal applications mainly in metallic colours (silver, bronze, specialist paint) on factories and offices.

The sinusoidal shape of 3''corrugated has recently spawned new generation lookalike profiles which are basically deeper profile versions and give an appealing 'wave effect 'for designers of modern metal clad buildings, again laid horizontally.

Corus Panels and Profiles (formerly Precision Metal Forming or PMF) continue to make 3''corrugated or 'wriggly tin' . The process is to feed coil through a series of rollers which gradually shapes the profile. The finished sheet is guillotined to length and the only restriction on length is the physical confines of the building it is being manufactured in (as well as transport of course). Demand today has diminished to about 1000 tonnes a year from an estimated peak of 20,000 tonnes annually in the UK. The standard dimensions are 13 x 3'' corrugations giving an effective cover width of 39'' or 990mms. The sheets are available in a range of thicknesses from 0.50mm to 1.20mm but the most popular was 0.70mm. At one time it was possible to obtain 8/3, 10/3, 101/2/3, 12/3 and 13/3.
The first digit representing the number of corrugations across the sheet. The sheets can also be curved to form 'Dutch barns', Anderson shelters' and pig housing as well as conveyors etc.

The biggest single customer in the sixties and seventies was the National Coal Board who used curved sheets for coal conveyor housings. 5.8.03

From DB, Galvanizers Association

I found the Corrugated Iron Club site quite fascinating and was interested to see that the development of corrugated iron is closely linked to the development of the galvanizing industry in Britain.

The first patents for galvanizing were taken out in 1836 although presumably there was some sort of fledgling industry before then. At presentations we always say that the galvanizing industry was a single-product industry in the early days and then invite audiences to guess what that product was - few guess corrugated iron! We do know that by 1860 the industry had grown to 10,000t per year so that would have been quite a few roofs, even using quite thick iron rather than today's thin steel. As your site notes, a lot of it was shipped to the four corners of the empire.

Interestingly, we were approached three or four years ago by the film company making "Anna and the King" (The King and I without music) who wanted verification that corrugated iron roofs could have existed in Siam in 1860. We trawled our members to find brochures etc that showed shipments going out around the world and so we argued that yes, it was quite feasible.

The good news for corrugated iron (and all things galvanized) is that the drop in sulphur dioxide in the atmosphere means that things will last about twice as long as they did ten years ago. (See our web-site for details: www.galvanizing.org.uk).

Galvanizing is not electro-deposition of zinc, that is zinc plating. Hot dip galvanizing (which corrugated iron is) is, as the name implies, dunking steel objects in molten zinc. The coating is much thicker and more wear resistant. 5.8.03