Richard Besant of Powdertech Corby on how developments in wood finish powder coatings on aluminium are providing a popular and realistic alternative to wood, as materials shortages increase
We have witnessed the increased use of architectural powder coatings to a point where powder coated metal is now a ‘dominant’ building material. Available in thousands of colours and textures, today’s architectural powder coatings can also transform metal into wood, stone or terracotta.
Emotional ties to natural elements
Architects and designers retain an understandable attachment to traditional building materials, and this is particularly evident with respect to wood. Wood has been the material of choice for building since time immemorial and our adherence to it is innate.
It could be argued that the appearance of wood, over and above any other qualities it possesses, prompts this emotional response. Other materials such as aluminium and steel may offer far better credentials for a particular building project, but do not inspire the same kind of ‘warm feelings’. The suggestion is that if these materials could be made to look like wood, then those crucial feelings of stability and security could be re-kindled.
The key factor is the accuracy with which the material can be made to resemble wood, however, since our eyes are very discerning. The latest ‘wood finish’ powders provide a very good representation with random, non-repeated patterns. The metal may not feel like wood, but to a large extent, ‘seeing is believing.’
Wellness benefits of wood
Planet Ark, based in Australia comments: “An increasing body of research is beginning to show that being surrounded by wood at home, work or school has positive effects on the body, the brain and the environment, and can even shorten hospital stays through reduced recovery times.”
The design of the Baptist Health and MD Anderson Cancer Care Centre, in Jacksonville, USA, adopted an holistic approach to the building design, using natural materials extensively. It was found that where wood was impractical to use, the designers retained the overall natural look on aluminium aerofoil blades, providing a credible substitute.
Safety is critical in building design and the flammability of wood makes it a specification choice with various added considerations. Treating wood to reduce flammability is expensive, and the chemicals used are not particularly environmentally friendly.
Safety is compromised when wood deteriorates over time, for example timber sliding shutters across the windows of an apartment block in north London became dilapidated and posed a danger to people walking below; Aluminium replacements were designed to avoid deterioration, and to retain the appearance of wood, a particular shade was chosen to coat the metal panels.
Preservation of trees
The World Bank estimates that between 1990 and 2016, the world lost 502,000 sq miles of forest, an area larger than South Africa. The argument over whether it is ‘environmentally responsible’ to use wood or not is a complex one. The timber industry may state that since wood can be regrown, it is sustainable and renewable; that trees store carbon dioxide as they grow and after harvest. However, National Geographic has argued that cutting down trees both adds carbon dioxide to the air and removes the ability to absorb existing carbon dioxide. According to the World Resources Institute, ‘if tropical deforestation were a country, it would rank third in carbon dioxide-equivalent emissions, behind China and the US.’
Powder coatings’ credentials
Powder coating has no effect on the recyclability of aluminium or steel, but has clear environmental advantages over wet paints and liquid wood treatments. Being a dry powder, it emits no volatile organic compounds (VOCs).
Wood on a building looks attractive when clean and free from lichen and mildew, but requires a long-term maintenance routine. Products designed to prevent lichen and mildew are not generally environmentally friendly, whereas powder coatings are developed to only need a quick wash over with water and a basic detergent.
Specifiers need to ask whether it is possible to use alternatives to timber which offer similar aesthetics, but without some of the issues. If one of the most important features of wood is its appearance, powder coating on aluminium or steel could be a useful and practical compromise.
Richard Besant is sales director at Powdertech Corby