What Is A Corten Steel Retaining Wall? Pros & Cons

There are many questions homeowners ask surrounding retaining walls. The two most common are what type of retaining should they choose and what type of contractors build retaining walls. If you have a modern aesthetic, you might consider a corten steel retaining wall. These are used primarily when you have a need for crisp clean lines and minimal wall thickness.  The great thing about using corten steel is the finished wall thickness is only 3/8” or 1/2” thick (the thickness of the steel itself).  So what is corten steel and why use it for a retaining wall?

What Is A Corten Steel Retaining Wall?

Corten steel retaining walls are made of a special type of steel.  Corten steel is a steel alloy specially designed to weather (aka rust) to a point where the rust layer actually protects the structural steel itself. This provides a maintenance free structural steel requiring no painting or corrosion resistance whatsoever.  

The use of corten steel in retaining walls and raised planters has become more and more common in recent years. Modern design has made its way out of high end architectural studios and into the mainstream. There are some limitations to corten steel when used as a retaining wall system. However, nearly all limitations can be overcome with the right engineering.  

How To Build A Corten Steel Retaining Wall

When building low 2’ or lower retaining walls with corten steel, you can usually find an experienced welder who can build the walls for you with the tie-backs required to prevent over-topping.  If you are building a wall taller than 2’ we would recommend finding a structural engineer experienced in designing corten steel retaining walls who can design the tie back system and frame which will prevent the steel plate fascia from over topping and failing.  

Corten Steel Retaining Wall Supporting Structure

Corten steel retaining walls can be used in a terraced design to create higher walls. These are often made up of multiple 2’ retaining wall systems which then can be planted and landscaped to create a beautiful landscape feature.

Corten Steel Retaining Wall And Boulders In A Backyard With Vegetation

Corten Steel Retaining Wall Disadvantages

There must be some drawbacks to corten walls, right?  Yes, there certainly are. One of the major drawbacks is the weathering process of the steel itself.  As the steel weathers initially, and less so over time, you will notice rust flowing off the walls and onto the surrounding landscape.  This is not a big issue if you are talking about only planting beds, and you probably won’t even notice.  But if your corten steel retaining wall is abutting a patio space or walkway, you might find rust staining which is virtually impossible to clean from stone or concrete.

Corten Steel Retaining Wall Staining A Backyard Patio

How To Design Corten Steel In A Backyard

Rust staining can be prevented with the use of a sealer. You can pay extra for pre-weathered corten steel, and you can also expedite the weathering process with chemicals, then follow up with a sealer.  However, there is a best practice to prevent rust staining. You should design your walls to be spaced from patios with a strip of landscape rock. This will give your corten steel some space to naturally weather.  Building a corten steel retaining wall gives you the freedom to have a maintenance free finish. Why not design your wall system to take advantage of that?