Roofing Ideas: Coloured Tiles, Rooftop Gardens, Hot Tubs and More

Getting Acquainted with the Work That Goes into Finishing Metal Roof Products

by Lily Carroll

Many residential and commercial property owners have embraced metal roofing because of the many incredible benefits that it offers. The popularity of metal roof installations primarily depends on the resistance it offers against rust and corrosion. These elements compromise a metal roof's performance and lifespan as well as its aesthetics. The technology used to manufacture metal roofing products is so advanced that today's metal finishes are not only visually appealing, but they also offer superior protection from rain, snow, ice, hail, UV radiation and other harsh weather elements. Read on to familiarise yourself with what happens when metal roof manufacturers are finishing the final product.


Aluminium, zinc or an alloy of both materials is usually used as protective coating for metal roofing products. These finishes are applied to the underlying metal (usually steel) via the hot-dip process at the steel mill. Generally speaking, the thicker the zinc coating, the greater the level of protection to the substrate metal. Zinc coating has a highly reflective, shiny colour that slowly tires out in uniform patterns over the lifespan of the roof, thus maintaining a rustic, natural look.

Unlike zinc coating, which relies on chemical reaction to protect the underlying metal, aluminium coating essentially provides a physical barrier formed through the oxidation process that occurs when aluminium comes into contact with oxygen in the air. The aluminium oxide layer formed is tough enough to provide protection against the inclement elements. Aluminium-zinc alloy coatings merge the barrier-protection of aluminium and the chemical reaction of zinc to offer protection for the final product.

Regardless of how well the coating is applied over the substrate metal, corrosion in roof products will take place at field-trimmed edges. Therefore, it would be best for all roofing to be factory-cut before being given a final finishing touch.


Once an anodised finish has been applied to the substrate steel, the roof will need to be painted. The paint is meant for aesthetic value as well as providing extra protection from rust and corrosion. Highly advanced paint technology is employed when it comes to metal roof painting. The roofing material is taken to a coil coating plant where flat sheets of metal are painted in giant coils. The paint is usually flexible enough so it can be roll-formed into the desired roof shingles, panels, tiles, shakes, or slate designs. A wide variety of paint colours can be used to provide the visual results that building owners love to see on their roof structures. Roof paint colour choices can also impact the energy performance of a building.