Steel Guide
Corten vs Traditional Steel
Everything you need to know about the differences between Corten weathering steel and standard carbon or stainless steel.
What is Corten Steel?
Corten steel — also known as weathering steel — is a steel alloy recognised for its distinctive rust-like appearance and exceptional durability. It is primarily made of iron, with trace amounts of copper, chromium, and nickel that enhance its weathering properties.
When exposed to the elements, Corten forms a stable, protective patina on its surface that acts as a natural barrier against further corrosion. This unique characteristic has made it a favourite among architects, designers, and landscapers worldwide.
Pros & Cons of Corten Steel
Advantages
Self-protecting patina
Forms a rust-like layer that acts as a natural barrier against further corrosion — no paint needed.
Low maintenance
Unlike standard steel, Corten does not need frequent repainting or coating over its lifetime.
High strength
High tensile strength suitable for structural, architectural, and landscape applications.
Unique aesthetic
Warm, earthy rust tones that complement natural environments and modern garden designs.
Long lifespan
Withstands UV, temperature extremes, rain, and humidity — built for the outdoors.
Cost-effective long term
Higher upfront cost is offset by lower maintenance and longer service life.
Disadvantages
Higher initial cost
Corten steel is more expensive to purchase than standard carbon steel upfront.
Limited availability
May require more lead time to source compared to commodity steels.
Not for all environments
Not ideal for highly corrosive coastal areas with constant saltwater exposure.
Design consideration
The aged, rustic look suits some styles but may not fit every project aesthetic.
Side-by-Side Comparison
| Aspect | Corten Steel | Carbon Steel | Stainless Steel |
|---|---|---|---|
| Corrosion Resistance | Excellent — protective patina forms naturally | Poor — requires paint or coating | Very good — but no patina, needs cleaning |
| Maintenance | Very low — patina is self-renewing | High — regular painting or treatment needed | Medium — periodic cleaning required |
| Strength | High tensile strength | Strong but less durable outdoors | Varies by alloy — generally strong |
| Aesthetic | Warm, rustic, natural patina look | Plain metallic finish | Shiny, modern, reflective |
| Initial Cost | Medium–High | Low | High |
| Long-term Value | Excellent — low upkeep | Poor — ongoing maintenance costs | Good — durable but expensive |