Corten steel - Here's what you need to know!

Corten steel - weatherproof structural steel with great potential

Corten steel is trending and is increasingly being used around the house and garden. Whether in the form of privacy screens, garden decorations, or raised beds: Corten steel scores points with its exceptional resistance to weathering and its unique appearance. We explain exactly what this structural steel is all about in this guide.

What is Corten steel and where does the name come from?

Corten steel was already used in the 19th century for bridge construction. Even then, this structural steel proved particularly useful because it easily withstands the elements – even though it is uncoated.

The exact trade name is COR-TEN® steel. The term is composed of CORrosion Resistance (rust resistance) and TENsile strength (tensile strength).

ELEO privacy screen made of Corten steel in front of the house entrance

Trending for home and garden: Privacy screen elements made of Corten steel, such as the ELEO privacy screen Reno. © ELEO

Is there a difference between steel and Corten steel?

In its pure form, Corten steel is a structural steel. However, copper, chromium, and nickel are added to it. This results in its special corrosion-resistant properties. Corten steel forms a special protective layer when the material is exposed to the elements – to alternating periods of dryness and moisture. This distinctive rust patina is characteristic of Corten steel and makes it so resistant. While structural steel can also rust, Corten steel, unlike structural steel, does not.

We have summarized the properties and advantages of Corten steel here:

Surface	Corten steel has a unique, orange-brown colour and a rough, cracked surface.
Corrosion-resistant	Corten steel has excellent corrosion resistance and is therefore ideal for outdoor use.
Malleability	Corten steel has high malleability and is therefore easy to work with.
Durability	Corten steel is very durable and can last for many years without significant changes or damage.
Environmental friendliness	Corten steel is environmentally friendly and can be easily recycled.
Costs	Corten steel is a relatively expensive material, but the investment is worthwhile due to its unique properties.

Why is Corten steel special?

The rust barrier layer that forms on the steel is strong and acts like a protective film for the material, preventing it from rusting and Corten steel can become unstable. This is caused by the oxide layer that forms on the surface. This layer is dense and almost impermeable to oxygen. Thanks to these properties, Corten steel is also frequently used in architecture. The colour of the rust patina is constantly changing and depends on the weather conditions. It can range from bright orange tones to brown hues. [Image of an ELEO Corten steel privacy screen in detail] Corten steel can take on different colours – from bright orange to dark brown. © ELEO

When You Should Seal Corten Steel

It might sound counterintuitive to seal Corten steel, since this structural steel is weather-resistant. However, if it's used indoors and outdoors – for example, in the form of privacy screens on the patio – sealing can be beneficial.

Reasons for sealing include:

The rust patina may initially rub off a little, leading to discolouration on the surfaces.
A specific rust condition should be preserved – for example, because the patina's colour is particularly appealing and shouldn't change further.