CorTen Steel in Signage and Architectural Cladding

What Is CorTen Steel?

CorTen is a high-strength, low-alloy steel designed to form a stable, protective layer of rust when exposed to the elements. Unlike conventional steel, which continues to corrode unless protected, CorTen’s oxidation process slows dramatically once the patina has formed, this outer layer acts as a natural barrier, shielding the steel beneath from further deterioration, eliminating the need for paints, coatings or ongoing corrosion protection.

The result is a living material that changes subtly over time, responding to its environment and settling into deep tones of burnt orange, umber and dark brown.

Why CorTen Works So Well for Signage and Cladding

• Aesthetic Impact That Can’t Be Replicated

CorTen’s appearance is instantly recognisable yet endlessly variable, no two panels age in exactly the same way, giving façades and signage an organic, bespoke quality that manufactured finishes simply can’t match.

• For signage, CorTen creates bold contrast, whether laser-cut typography against a negative space, folded monoliths or layered wayfinding elements.
• In cladding, it adds depth, texture and a sense of permanence that anchors a building to its surroundings.

• Low Maintenance, High Longevity

Once the patina has stabilised, CorTen requires minimal maintenance, there’s no paint to flake, no coating to reapply and no need for regular refinishing. For estates, public realm projects, campuses and commercial developments, this translates into lower whole-life costs and reduced disruption, without compromising on visual quality.

• Structural Strength and Versatility

CorTen isn’t just a surface material, its strength makes it suitable for large-format panels, folded profiles, deep returns and structural signage elements. It can be:

• Laser cut for precision typography and detailing
• Folded and formed for three-dimensional signage and cladding
• CNC profiled for bespoke patterns and perforations
• Combined with materials such as glass, timber or anodised aluminium for contrast

This flexibility makes it ideal for integrated façade and signage strategies where consistency of material language matters.

CorTen in Architectural Cladding

In cladding applications, CorTen steel is often chosen to soften large elevations, break down mass or introduce warmth to modern forms, it works particularly well in:

• Cultural and civic buildings
• Educational campuses
• Commercial and mixed-use developments
• Landscaped and heritage-sensitive environments

As the patina matures, the building develops a sense of age and belonging, often blending beautifully with brick, stone, concrete and greenery.

Designers should consider detailing carefully, allowance for run-off during early weathering, appropriate drainage and fixing systems that respect the material’s movement and behaviour over time.

CorTen Steel in Signage

For signage, CorTen communicates confidence and longevity, frequently specified for:

• Building identification and branding
• Totem signs and monoliths
• Wayfinding and placemaking features
• Interpretive and heritage signage

Signage elements can be illuminated, backlit or left unlit to allow the material itself to do the talking, we can also pre-weather and seal the Corten for use when members of the public can feel and observe the material up closely. When paired with subtle lighting, CorTen signage becomes particularly striking at dusk and night.

Sustainability Credentials

CorTen steel aligns well with sustainable design principles:

• Long service life reduces replacement and waste
• No paints or coatings mean fewer chemicals and lower embodied maintenance impacts
• Fully recyclable at end of life
• Its durability and low intervention requirements make it a responsible choice for projects focused on long-term environmental performance

Things to Consider When Specifying CorTen

While CorTen is robust, it does require informed design and manufacture:

• Weathering phase: Early runoff can stain adjacent materials if not properly managed
• Environment: CorTen performs best in alternating wet/dry conditions; constantly damp or marine environments may require additional consideration
• Detailing: Fixings, backing materials, and interfaces must be compatible

Working with NES as an experienced manufacturer ensures the material is pre-weathered where required, fabricated and installed correctly, delivering the intended aesthetic without unwanted surprises.

A Material That Tells a Story

CorTen steel is more than a finish, it’s a narrative material, it speaks of time, exposure and authenticity, delivering presence without polish, strength without shine and beauty without artifice.

For projects that demand character, longevity and architectural integrity, CorTen steel remains one of the most compelling materials available.