Galvanized Steel has been around for centuries. To put it simply, it is made by coating zinc onto the steel substrate to protect it from rusting.
Galvalume is a relatively newer product. On top of the zinc coating, it also has aluminum to make the steel last longer.
Zinc-Aluminum-Magnesium, the order of the elements is in correspondence to its respective amount in the coating, uses the state-of-the-art alloy technology and has the best performance among the three, and it is paramount to stainless steel in some occasions for only a fraction of its price.
Besides the substrate, paints and the amount of metal coating can also affect the life span of steel sheets.
