Corten steel, also known as weathering steel, is an alloy that forms a rust-like protective layer on its surface when exposed to the weather. This unique patina develops over time and prevents further corrosion, making it a durable and aesthetically pleasing material for outdoor uses.
Material details
Corten steel develops a protective rust patina when exposed to weather cycles, transforming from its original grey-blue finish to warm orange tones before settling into a stable, deep brown layer.
This oxidation process typically takes 6-12 months depending on climate and exposure, with the patina continuing to deepen and stabilise over several years. The rust layer acts as a barrier that prevents further corrosion, eliminating the need for painting or sealing.
Care and maintenance
Corten steel requires minimal maintenance once its protective patina has fully developed. During the initial weathering period, expect rust runoff when the steel gets wet - this can stain concrete, pavers, or adjacent surfaces. Once stabilised, the patina sheds minimal rust and protects the steel indefinitely.
Clean: With water and a soft brush to remove debris, dirt, or salt buildup, particularly in coastal environments where salt concentration is higher. Avoid pressure washing or abrasive cleaning methods that can damage the protective rust layer.
Accelerate the weathering process by repeating a wet-dry cycle, using either a 50/50 mixture of white vinegar and water, a salt water solution (1 tablespoon per cup of water), or plain water.
