Landscape architects have been fans of weathering steel for many years now. They like its burnt-orange tones, which blend well with greenery and vegetation and offer lots of elegant and contemporary design solutions. And they also like its strength and longevity, which can deliver significant time- and cost-savings.Corten steel’s unique properties first emerged in 1930s America.
Manufacturers of railroad coal wagons discovered steel alloys which developed a protective layer of rust when they were exposed to the atmosphere. This oxidation process gives Corten steel its distinctive earthy-brown patina, and it’s this which provides a protective layer over the steel and lets it withstand all types of weather corrosion, in a way that carbon steel just can’t match.
Architects quickly adopted Corten steel, featuring it in iconic buildings in Chicago and New York and in many other cities across the world.
Corten steel’s highest-profile use in the UK is probably Sir Antony Gormley’s 1998 Angel of the North at Gateshead - at 20m tall and 54m across, the largest sculpture in the UK. Built with Corten to signify the industrial heritage of the North-east, the Angel was designed to withstand winds of over 100mph, showing how versatile and resilient Corten steel is. The funky, post-industrial vibe it gives off has also added to its appeal.
Corten – an abbreviation from Corrosion resistance-tensile strength
- has come to be known as the generic term for weathering steel but the name is actually registered as a trademark by the United States Steel Corporation, which no longer manufactures it. That notwithstanding, the terms have become synonymous today.
As well as being strong, CorTen is also thin and flexible. This makes it ideal for bordering, retaining walls and raised flowerbeds, as well as water features and art installations.
It can be cut, fabricated and welded in the same way as other mild steels and, like other steels, there’s no danger of it harming adjacent plantings or surroundings. In fact, there are environmental benefits from using CorTen as it absorbs high levels of Co2.