The primary function of the metallic coating on metal roofing is to provide corrosion resistance. Metal roofs are exposed to various environmental factors, such as moisture, oxygen, and pollutants, all of which can lead to rust and degradation of the metal over time. The metallic coating acts as a protective barrier that prevents these elements from directly contacting the underlying metal substrate, thus extending the lifespan of the roofing material.
While aesthetic appeal and various colors do enhance the visual aspects of a roof, it is not the fundamental purpose of the metallic coating. Similarly, although certain coatings can improve thermal insulation properties, their main role is not insulation but rather protection against corrosion. The suggestion that the coating creates a textured surface for better water drainage does not align with the primary reason for applying these coatings, which centers on protecting against corrosion.