Galvalume metal roof and siding panels are coated with a mixture of zinc and aluminum and siliconized coating to help resist scuffs and fingerprints better than a bare metal product.
Galvalume roof rusting.
For these reasons galvalume metal roofs are much more popular.
On top of the galvalume is a layer of stone texturing coated with acrylic resin that ensures a completely nonporous water proof uv resistant surface that won t rust or corrode.
The one exception is when the coating is penetrated scratched or chipped by falling or blowing debris for example.
Galvanized metal roofs may also be used by architects looking for a traditional rusted appearance in a new building.
Via abc metal roofing.
How to repair a rusted metal roof.
Galvalume and galvanized steel roofing are affected differently by corrosion.
Corrosion is the death of metal roofing as we all know.
Compared to shingles or rolled roofing metal roofing is easy to install and it can last for 20 years or more but it is susceptible to a defect that never.
Typically galvanized sheet roofs are used mainly for agricultural buildings where rust is less of an issue and costs must be kept low.
Aluminum has tremendous corrosion resistance so it will generally corrode more slowly than galvanized steel.
If your roof were to rust and it s under warranty then attempting to clean off or coat the rusted area may void your roof s.
The mixture of zinc and aluminum protects the galvalume metal against corrosion and rust helping galvalume typically last much longer than galvanized steel.