CORTEN steel or Weathering Steel is made up of a group of steel alloy materials which when left uncoated and exposed to the natural elements develops a very distinguishable rust patina.
CORTEN is known for its superior corrosion resistance. This is because the surface of the steel forms a protective oxide layer when exposed to the weather. In other words the steel is allowed to rust in order to protect itself. The protective surface layer continues to regenerate over years of exposure.
The information provided here is a generic guide only and to outline minimum installation requirements for warranty. Like trellis and other landscaping materials, specific applications vary and responsibility remains with the installer. This is a DIY product, basic handyman/carpentry skills are required. Consult your local retailer or a landscaping professional if unsure.