Not all coated steel is the same! One of the fastest growing types of metal roofing available is that which uses a coating alloy of aluminium and zinc with a specific formulation patented by Bethlehem Steel some 40 years ago, which is being increasingly used in projects all over the globe for both its durability and proven performance in field service. It is widely referred to as 55% Al-Zn coating technology.

In America and abroad, this product has been sold commercially since 1972 under the name Galvalume®. Bethlehem Steel later licensed other major steel companies to produce and sell the product under patent. All products worldwide use the same coating alloy and technology, and benefit from global testing and performance trials.

Despite the Covid-19 pandemic which negatively impacted economies worldwide during 2020, annual licensed 55% Al-Zn production rose by 2.1% to almost 9.1 million metric tons in 2020, and a cumulative worldwide total of over 180 million metric tons since inception.

Cumulative Worldwide 55% Al-Zn Sheet Production Through 2020 (Metric Tonnes)

This follows on from a 5.2% increase in production in 2018, and a whopping 4.4% growth in production during 2019. 55% Al-Zn has seen a continued upward trajectory over the past year, in stark contrast to global GDP which is predicted to shrink due to the economic woes brought on by Covid-19.

What is this coating alloy made up of?

A carbon steel base sheet is continuously hot-dipped to coat it with an alloy consisting of 55% aluminium, 43.4% zinc and 1.6% silicone. This alloy prolonging the life of the inner steel core by protecting it from perforation due to exposure to the elements.

This alloy in this particular combination allows for the best characteristics of both aluminium and zinc metals to perform in a specific synergy for lasting durability which helps to explain why it has become one of the fastest growing materials in today’s metal roofing market.

Increased service life

Service life expectancy of 55% Al-Zn sheets has gradually been increased from 20 to 60 years, based on longer term data from actual building installations using the material. This three-fold increase in estimated service life is the result of continual refinement to the production technology as well as improved recommendations for best practices in terms of design, installation, and maintenance.

Sourcing your 55% Al-Zn coated steel from a licensed supplier is the only assurance for obtaining this length of service life.

The Safal Group was the first and remains the foremost producer of 55% Al-Zn coated steel on the continent. The Group has three steel coating plants: in South Africa (Safal Steel in Cato Ridge), Tanzania (ALAF in Dar es Salaam), and Kenya (Mabati Rolling Mills in Mombasa).

Test sites are located in many areas of Eastern and Southern Africa, proving the service life of the Group’s products in various environments. Research and Development is ongoing, and always remains a priority in ensuring that Zincal®, Colorplus® and Optima® provide the lasting value and performance for which they are known and trusted by millions of building owners, professionals and specifiers throughout the continent.

The Safal Group is BUILDING AFRICA WITH PRIDE.