Rust Never Sleeps

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Updated: September 28, 2020

The use of Corten steel products in landscape design continues to push the boundaries of contemporary landscapes with designers often utilising this interesting and popular material to create architectural design solutions that provide a unique characteristic to make them stand out from the crowd. Corten steel has a multitude of uses that bring an industrial element to the landscape but at the same time provides a harmonious link between other hardscape and soft landscape elements. Corten steel landscape elements have risen in popularity in achieving a modern design component by providing a rustic element, pardon the pun.

Corten steel is a high durability steel alloy product with an oxide layer or patina that forms on the surface giving that classic rust appearance. Produced from a copper chromium steel alloy, Corten is also referred to as Weathered Steel, the ‘Cor’ in the trade name refers to the metal’s resistance to corrosion and the ‘ten’ denotes the tensile strength of the metal. Corten has a high strength metal and does not require surface preservation as the surface is corrosion resistant. The light weight of Corten is another feature that makes it very popular as a landscaping element because it can be manipulated into a range of shapes and can also be welded with a long lasting, low maintenance aesthetic. The application of Corten in landscapes is set to continue to increase in popularity.

They say that rust never sleeps but with Corten the oxide layer stops the corrosion process. Basically, the steel rusts in order to protect itself. The result over time as the steel is exposed to the elements is a uniquely beautiful product displaying a range of velvety bronze shades to a rich orange and browns.

Corten is available in a range of sizes with sheet thickness ranging from 1.6mm up to 10mm. Sheet sizes are available in varying widths from 1200mm to 6000mm, but they can be cut to size. Many landscape elements made from Corten can be prefabricated eliminating the need for cutting or welding components onsite.

Corten steel products can be used in similar circumstances to more traditional materials such as timber, concrete or masonry products. The versatility of Corten brings an ageless element that can be applied to a range of landscape fundamentals including garden edging, retaining walls, building cladding, fire pits, laser cut screen panels that can be customised in a multitude of profiles, and sculptural elements that can be forged into any number of different shapes and sizes as well as planting containers.

The versatility and affordability of Corten products is only limited by the imagination with many suppliers offering customised design builds for any type of feature. Laser-cut decorative privacy screens Corten is available in a range of sizes with sheet thickness ranging from 1.6mm up to 10mm. Sheet sizes are available in varying widths from 1200mm to 6000mm, but they can be cut to size. Many landscape elements made from Corten can be prefabricated eliminating the need for cutting or welding components onsite.

Corten steel products can be used in similar circumstances to more traditional materials such as timber, concrete or masonry products. The versatility of Corten brings an ageless element that can be applied to a range of landscape fundamentals including garden edging, retaining walls, building cladding, fire pits, laser cut screen panels that can be customised in a multitude of profiles, and sculptural elements that can be forged into any number of different shapes and sizes as well as planting containers and during both cold andhot weather can result in root damage to plants. Liners are not usually necessary for Corten containers but the Styrofoam insulation or any other insulating liner will provide plant installations with a much healthier root environment. Corten is a great substitute for other traditional materials used in planter boxes such as glass recycled concrete, terracotta and plastics, and the appearance of the rusted surface of Corten in a garden is complementary to other landscape elements, particularly plantings.

The appearance of Corten elements can also be changed with an application of oil although this may be required on an annual basis to maintain the desired effect. One drawback with Corten is that it will leach and can stain surfaces, so it is recommended to use a base for planters. There are alternatives though and with some clever planning Corten containers or other structures can be embedded into a substrate material below pavers or concrete surfaces in a trough to eliminate the leaching impacts on hardscape surfaces. A sealant such as a clear urethane can also be applied to the surface of Corten planters and screens to prevent any further rusting once the desired appearance is achieved but is not necessary.

The appearance of Corten steel makes it ideal for use in rock gardens and lends itself to the aesthetic of native and xerophyte landscapes almost seamlessly. Sheeting can be used as risers in steps and gardening edging with some suppliers providing a rolled edge material making it safe for playground applications.

As with any material used in landscape construction there are pros and cons. With Corten steel products one of the biggest drawbacks is that the corrosion resistance of Corten can be compromised in coastal environments. Where salt exposure is high, the protective metal patina may not stabilise and the metal may continue to corrode due to the presence of salt deposits into the oxide layer of the metal. The continuous deposit of salt on Corten in coastal environments will result in the development of akageneite, which results in a flaking form of non-adherent rust. There are also issues that can result in continuous corrosion where Corten may be constantly placed in direct contact with water. In these situations, the metal may continue to corrode, which can be problematic with Corten planters where moisture will tend to accumulate at the base of joins. Problems may also be experienced with the welds of joins in Corten features, which may corrode at a faster rate depending on the quality of the weld and the material used.

Despite the limitations outlined, Corten is definitely a landscape material that provides an enormous range of possibilities to landscape designers to incorporate artistic and structural components that will complement modern day contemporary landscapes. Apart from periodic inspection and hosing of the metal surface occasionally with water to remove any debris or contaminant deposits from its surface, Corten tends to be maintenance free. This is a considerable advantage in landscape maintenance where other materials may require regular applications of paints or preservatives. The useful life expectancy of Corten is another advantage over more traditional materials such as timber. The dynamic nature of Corten means that its appearance will continually change as it is exposed to moisture and dries out again. The beauty of this product is that it will also change in response to the environmental conditions at any point in time, giving rise to a material that is transformed into something that is multi-dimensional. Landscapes will never be the same as Corten steel becomes increasingly more popular with landscape designers and the end users in commercial and residential settings.