Corten Steel Edging – A Quick Guide To Weathering Steel

Introduction

Corten steel edging has become increasingly popular in domestic, civic, and commercial landscape design in recent years.

But what makes Corten Steel so special and why is it gaining popularity? Is it the best choice for your garden edging project, and is all Corten steel edging the same?

If you’re considering using Corten steel edging in an upcoming gardening project and want to understand if it’s the right choice, this 8-minute read is a good starting point.

Why Read This Article?

Read this article if you’d like to…

• Find out what Corten Steel Edging is and what sets it apart.
• Discover the reasons behind the increasing popularity of Corten Steel Edging.
• Appreciate how different Corten Steel Edging looks before and after the weathering process.
• Explore the advantages of choosing Straightcurve’s weathering steel edging.

What is Corten Steel Edging and is it the same as Weathering Steel Edging?

Cor-Ten, also known as Corten, is a specific brand name that refers to an alloy known more generally as weathering steel. This type of steel is produced by various manufacturers under different names, but it is essentially the same alloy. The weathering steel alloy is standardised globally, with slight variations between the standards.

U.S. Steel was the first company to produce and trademark weathering steel as Corten in the 1930’s. The brand has become so well-known that it is often used as the generic term for Weathering Steel, much like Hoover and Google. The name “Corten” refers to the corrosion resistance and high tensile strength of the steel.

In summary, all types of weathering steel, including Corten, Redcor, SSAB, and others, have a very similar composition in line with the standards used for weathering steel (ASTM, EN ISO, BS ISO, DIN, etc), and they can all be expected to perform similarly.

Why is Corten Steel Edging popular in garden design & landscaping?

Corten Steel Edging is a popular choice in landscape design due to its aesthetic appeal, strength, durability, and longevity. It outperforms other garden edging materials and metals, thanks to the unique properties of Weathering Steel, which sets it apart from typical Mild Steel.

Corten Steel Edging, or any weathering steel equivalent, is known for adding a rustic and natural look and feel to garden designs due to a unique rusted patina that develops over time with exposure to the elements. You’ll find weathering steel edging used extensively in beautifully landscaped gardens and display homes like the Rural Building Company display homes featured in this article.

Weathering steel slowly changes colour, darkening over the years. This creates unique looks based on microclimatic conditions at each site.

Note: The afore-mentioned patina not only looks good but also acts as a protective coat for weathering steel. It continuously regenerates on the surface to prevent aggressive and unsightly rusting, which is common with mild steel. This is why weathering steel is used extensively in outdoor locations and in high-quality landscape gardens.

How long should you expect Corten Steel Edging to last?

In terms of lifespan, it’s impossible to offer a one-size-fits-all promise with the variety of soil and atmospherics that can impact this natural process of corrosion. We know weathering steel edging can last decades and hold its structural integrity even as it corrodes. This is a product deserving of its long-lasting credential, but not one to carry a fixed-guarantee due to all the factors in play.

Many companies claim that Corten Steel Edging will last forever, but that’s not true. It is more accurate to say that weathering steel is much more durable and typically lasts 4-6 times longer than mild steel. In terms of lifespan, 1.5mm panels of Corten or weathering steel is equivalent to a 6-9mm mild steel flat bar. In practical terms, this means Corten Steel Edging can last anywhere between 5 and 30 years.

The actual lifespan of your Corten Steel Edging depends on various factors such as your location, water conditions, and soil conditions.

If you use bore water, which is often acidic, the lifespan of the edging will be significantly reduced. If you use tap water, the edges will last longer unless the water has high chlorine levels. Additionally, edges located close to a pool may not perform as well unless they are sealed.

To be certain about the quality of your chosen steel edging, you can always request the test certificate. All steel batches are tested at the steel mill, and a certificate confirming the composition is always available. At Straightcurve, we handle all product design in-house and manufacture our products through our fabrication partner, which means we have access to all certifications.

Summary: Corten Steel Edging can be expected to last for at least 10 years in most situations. Consider this when you are thinking about making a purchase.

What does Corten Steel Edging look like before and after patina formation?

The manufacturing process of weathering steel leaves the surface in a dark, almost black state. The weathering process causes this initial layer to break down before the desired protective patina layer can be established.

The change in colour (from near black to a rich ochre) occurs due to the natural process of patina formation on the surface, giving it a timeless rusty look. This process is a result of exposure to the elements, particularly moisture and air. The pace of this colouration is difficult to predict as it depends on local circumstances and the season of installation. In more humid conditions or wetter seasons, you may see a change within days and weeks; however, it can still take months for a solid, even patina to develop.

To expedite the process, use soapy water and rub the surface down a few times, allowing significant dry time between applications. This helps even patina development by dispersing residual oils on the surface. Do not use acids or salts to speed up the process, as this will prevent the formation of a healthy patina and can be detrimental to its lifespan.

TIP: Some people choose to buy weathering steel early and allow it to pre-rust before installation. If doing this, ensure it is unstacked and can air dry without water pooling on any surfaces.

What’s good about Straightcurve Steel Edging?

Any certified weathering steel garden edging product, whether it’s the branded Corten Steel Edging or an equivalent from a different brand, will perform similarly.

All of our Straightcurve Weathering Steel Edging is quality-assured at our factory, and we have the material certification to prove it.

If you prefer the rusted patina look and Corten durability, make sure you purchase weathering steel and not mild steel, which will deteriorate quickly when exposed to the elements.

Apart from material quality, the difference between a generic weathering steel edging (or a product made with Corten) and Straightcurve Weathering Steel Garden Edging lies in the quality of design and production.

All of our steel garden edging products are user-friendly, stay securely in place once installed, and look terrific, thanks to our high manufacturing standards and virtually seamless designs.

Conclusion + Helpful Resources

I hope this short article has given you an insight into Corten Steel Edging, otherwise known as Weathering Steel Edging.

If you want to know more about our products, check out these links:

• Download Our Product Catalogue – Download the pdf to view our entire range.
• Check Out Our Image Gallery – For examples of gardens made with Straightcurve garden edging.
• View Installation Videos – Here you’ll discover how easy it is to use our products in your garden.
• Find Your Nearest Dealers – Find stockist locations and details on our “Where To Buy” map.
• Request Pricelist & Brochure – Submit for a brochure, pricelist, and stockist’s details by email.
• Downloadable This Case Study PDF – Save this in a folder of inspirational ideas.
• Garden Edging: DIY Gardener’s Essential Guide – Your deep dive into all things Garden Edging.