Notes: Some installations may require a concrete collar to meet
load rating. Load ratings are based on encasing product in
concrete. Product must be installed using NDS instructions.
Cast iron grates will oxidize over time and rust, forming an
iron-oxide patina. The iron-oxide layer begins red-orange in color and
ages to a deep, rich brown. This patina is tightly adhered and protects
the iron beneath it from further oxidation. Iron grates with a rust
patina are structurally sound and will last for decades.
