As industries increasingly prioritise lifecycle performance, durability and lower maintenance costs, demand continues to grow for materials that can withstand harsh operating environments.

Among the most successful innovations in coated steel technology is Galvalume®, also known as Zincalume®, Zincal or Aluzinc, a zinc-aluminium coating system that delivers exceptional corrosion resistance across construction, automotive and industrial applications.

Galvalume® consists of a coating containing approximately 55% aluminium and 45% zinc, creating a corrosion-resistant barrier that performs exceptionally well in many building and industrial applications particularly at the coast in South Africa but with a high-quality organic topcoat.

The coating is widely used for roofing systems, wall cladding, building panels and various industrial components where long-term durability is required. According to Simon Norton, Director of the International Zinc Association (IZA) Africa, Galvalume® or Zincalume® has become a preferred solution for many applications because of its enhanced corrosion resistance.

A highly effective coating system

“The combination of zinc and aluminium creates a highly effective coating system that offers excellent protection in a wide range of environments. This makes Galvalume® or Aluzinc particularly attractive for building applications where long service life is a priority,” says Norton.

Galvalume® protects steel surfaces by providing superior corrosion protection through a combination of sacrificial (cathodic) protection and barrier inhibition. The aluminium-zinc alloy coating utilises zinc to cathodically protect steel at cut edges, while the aluminium component forms a durable, insoluble oxide layer. This creates a dense, long-lasting barrier that effectively seals the base steel against a corrosive atmosphere.

A key advantage of Galvalume® is its ability to provide superior corrosion resistance in applications that do not involve severe forming or fabrication after coating. This has contributed to its widespread adoption in the construction sector, particularly for roofing and cladding systems exposed to the elements.

Automotive and industrial applications

In addition to building applications, Galvalume® is also used in certain automotive and industrial applications where resistance to heat and corrosion is important. As asset owners and developers increasingly evaluate materials based on lifecycle performance, durable coating systems continue to gain importance.

“Selecting materials that can withstand environmental exposure over extended periods contributes directly to lower maintenance costs and improved asset performance. Galvalume® has demonstrated its value in this regard across numerous applications,” notes Norton.

With its proven combination of durability, corrosion resistance and versatility, Galvalume® continues to support the development of resilient infrastructure and buildings throughout Africa.