The thickness of the zinc coating on galvanized steel directly impacts how long it resists rust. A thicker coating provides a stronger barrier and more sacrificial protection, which can significantly extend its lifespan especially in harsh environments. However, once that coating wears down, the underlying steel is vulnerable to corrosion.
Aluminum, on the other hand, does not rely on a coating. It naturally forms a thin, self-healing oxide layer that protects it from corrosion, even if scratched or exposed. This means aluminum’s longevity is not dependent on added coatings, making it more consistent in long-term durability across various conditions.