Eventually, the zinc will be corroded, although how long this takes depends on the thickness of the coating and the environment. Galvanized steel has a much shorter lifespan when it’s regularly exposed to rain or seawater.
Various American Society for Testing and Materials (ASTM) specifications provide guidelines and continuity for the thickness of galvanized metals. Galvanization of nails and screws is the most common method of preventing the unsightly staining seen on many types of house siding.
Read more: Galvanizing Thickness