Despite being malleable and easy to work with, copper is a remarkably tough material. It’s totally non-combustible and possesses a melting point of 1,085 degrees, nearly double that of aluminium. Typically lasting 100 years or more, copper cladding very rarely has to be replaced and low to zero maintenance costs can be expected over the operational life of the building, which more than offsets any initial high cost in the original application. Across its life cycle - from extraction to recycling - copper has a minimal impact on energy consumption and natural resources, while its use has an immensely positive impact on energy efficiency, indoor air quality and life-cycle costs.
As well as possessing impressive durability, copper is very also lightweight, which can be especially important on large buildings. Some other cladding options could add considerable weight to a building’s structure, making the final design more difficult to engineer, and heavier systems tend to be more challenging during the installation phase. As well as the metal being inherently more lightweight than most others, copper cladding is also typically supplied in a thinner gauge which helps to cut down on material costs and ensures copper is an excellent way to economically cover large areas.
Copper is self-cleaning in natural rainfall, eliminating the need for cleaning costs and any potential pollution associated with external cleaning materials. At the end of the building life copper is also 100% recyclable. In a cladding application, the copper used is roughly 50% recycled material, a number which is slowly rising.
No other metals offer quite such a range of attractive colours as copper and its various alloys: the brownish red of copper, the gold of brass, the chocolate brown of bronzes. Copper’s main draw from an architectural stance is the eye-catching patina that it develops through age and exposure to the elements. A thin layer of various chemical compounds such as oxides, carbonates, sulfides or sulfates forms on metal’s surface during exposure to atmospheric elements, altering the finish over time. This weathering process is not necessarily uniform depending on the building’s exposure to the elements, often resulting in some more unusual finishes.
Different metals experience this patina in different ways, producing a range of colours - the rust which forms on iron or steel over time is also essentially a patina - but copper’s blue-green patina is considered the most popular and has been used to great effect on many well-known structures.
Arguably the most famous use of copper is on The Statue of Liberty; the monument’s pale blue-green colour is synonymous with the iconic landmark, but back in 1885 when it was first constructed the statue’s copper plates would have been brownish red, not patinating to its now-trademark colour for over 15 years. The idea of a brown Statue of Liberty certainly seems slightly bizarre but that’s how it would have looked initially before its panels weathered to the recognisable colour it is today.
Occasionally copper is supplied in pre-patinated form, the panels already possessing the weathered look at the time of installation. CGL supplied its Wallplank system in pre-patinated copper for Cambourne Police Station, the cladding already covered by a permanent layer of oxidation that will prevent further corrosion whilst permanently retaining the attractive shade of blue-green.
Check out our other projects for yourself to see the diversity of our work with copper and its alloys.