Weathering Metal Roof Panels - California Rusted / "Corten" Roof!

Weathering Steel is best known under U. S. Steel's trademarked name COR-TEN ®, which is no longer produced in the United States.

One of the ASTM accepted equivalents of COR-TEN ® for thin sheet steel is ASTM Grade A606. This type of steel will form a stable, rust-like patina when exposed to the weather.

Weathering rates can vary depending on the presence of pollutants in the air (urban vs. rural), as well proximity to coastal environments. It is not recommended for humid environments where the patina may not stabilize, allowing for corrosion to continue and compromise (rust through) the panel.

The initial weathering process may result in a rust colored run-off onto surrounding areas.