PPGI refers to pre-painted galvanized iron, which uses galvanized steel as the base material.

PPGL refers to pre-painted galvalume steel, which uses an aluminum-zinc coated base.

The difference in the base coating affects performance, especially in corrosive or moisture-prone environments.

PPGL usually offers better corrosion resistance and can be a stronger long-term solution for demanding roofing applications.

When durability is the priority, PPGL is often considered the better option.