Copper is functional, antimicrobial and resistant to corrosion, but above all, copper is beautiful.
Traditionally, copper is used in our homes, offices and public buildings, in roofing systems, flashings and copings, rain gutters, downspouts, domes, spires, vaults, wall cladding and building expansion joints.
However, during the last twenty years, copper has been used in design in a wide range of buildings, incorporating innovative styles, varieties of colours and different shapes and textures. Copper clad walls are a 21st century ‘invention’ used in both indoor and outdoor environments.
Historically, some of the world’s most distinguished modern architects have relied on copper. These include, Frank Lloyd Wright, Michael Graves and Malcolm Holzman to name a few. Architect Frank O. Gehry’s enormous copper fish sculpture atop the Vila Olimpica in Barcelona is an example of the artistic use of copper in architecture.
Copper is most noticeable for its range of colours from a bright metallic colour to iridescent brown to near black and finally to a greenish verdigris patina. Architects and designers refer to the variety of browns as russet, chocolate, plum, mahogany and ebony and have long coveted this distinctive patina.
But the use of copper is not of recent times. Copper has played a role in architecture for thousands of years. Some examples of its use in ancient Egypt are the doors to the temple of Amen-Re, which were clad in copper. Centuries later, copper and its alloys were an integral part of mediaeval architecture. Examples of these are the doors of the Church of the Nativity at Bethlehem, the copper roof of Hildersheim Cathedral and the copper roof of Hildersheim Cathedral.
The benefits of using copper over other metals are:
- Its resistance to corrosion – copper provides excellent corrosion resistance and corrodes at negligible rates in unpolluted air, water, de-aerated non-oxidizing acids and when exposed to saline solutions, alkaline solutions and organic chemicals. Copper roofing corrodes at rates of less than 0.4mm in 200 years.
- Its durability – Copper roofs are extremely durable in most environments, mostly because of the protective patina that forms on copper surfaces. Tests conducted on 18th Century copper roofs in Europe have shown that theoretically, they could last for at least one thousand years
- Low thermal movement – properly designed copper roofs minimise movement due to thermal changes. Copper’s low thermal expansion, which is 40% less than zinc and lead, helps to prevent deterioration and failure. Copper’s high melting point ensures that it will not creep or stretch as some other metals do.
- Low maintenance – copper does not require cleaning or maintenance thus making it suitable for areas that are difficult or dangerous to access after installation.
- Lightning protection – copper and its alloys are the most common materials used in residential lightening protection. Copper also effectively facilitates the transmission of lightning energy to the ground because of its excellent electrical conductivity.
- Antimicrobial properties – International tests have proved that uncoated copper and copper alloys have strong intrinsic antimicrobial properties against a wide range of disease-resistant bacteria, moulds, fungi and viruses. These findings have opened the door to the development of copper or copper alloy products for use in architecture. To meet specific design needs, antimicrobial copper-based products are available in a wide range of colours, finishes and mechanical properties.
- Design continuity – Architects often look to architectural copper for continuity in design elements. A copper roofing system for example, may be designed with copper flashings, vents, gutters, and downpipes. With the growing use of vertical cladding, vertical and roofing surfaces can run into each other thus ensuring complete continuity of material and performance.
- Sustainability – Copper is a sustainable material; its durability offers long service with little maintenance, its high electrical and thermal energy efficiencies reduce the waste of electrical energy, its antimicrobial properties destroy pathogenic microorganisms that cause disease and its ability to be continuously recycled without any loss in performance ensure its responsible management as a valuable resource.
In South Africa copper is broadly used in architecture, from private homes to shopping malls and offices. Perhaps the most stunning application of the use of copper is //hapo Museum just south of Pretoria. //hapo Museum, designed by Mashabane Rose, is a copper-clad structure based on a concept which originates from a traditional healer’s garden seen at a homestead in Kuruman in the Northern Cape. “With walls and roof all clad in copper sheeting, the building will with time, weather to green to merge with the natural landscape” quotes the architect.
Says Evert Swanepoel, Centre Director of the Copper Development Association Africa (CDAA): “The efficiency of the use of copper products in architecture is without question however, the sheer beauty of the metal is often overlooked. It is time that South Africa starts appreciating the aesthetics of using copper in architectural design”.
The Copper Development Association Africa has represented the local copper industry since 1962. On behalf of its members, the organisation is committed to promoting and expanding the use of copper and copper alloys throughout Africa.