Nordic Copper offers an extensive range of natural surfaces and alloys that can be applied in numerous ways for cladding and roofing on a wide variety of building types – from major public buildings to distinctive individual homes. A growing series of building studies (via www.nordiccopper.com) showcase the diversity of surfaces, forms and applications available today.
Copper’s unique architectural qualities are defined by its naturally developing patina – which cannot be replicated successfully using other materials with surface coatings. The patina film provides impressive protection against corrosion and can repair itself if damaged, giving its exceptional longevity.
Within a few days of exposure to the atmosphere, a copper surface begins to oxidise, changing from the ‘bright’ mill finish to a chestnut brown, which gradually darkens over several years to a chocolate brown. Continued weathering can eventually result in the distinctive green or blue patina seen on older roofs.
Natural Living Surfaces
The Aurubis ‘Nordic Copper’ range provides all these surfaces straightaway. The processes involved are generally similar to those taking place over time in the environment, utilising copper mineral compounds, not alien chemical processes.
All these surfaces form an integral part of the copper, generally continuing to change over time, and are not lifeless coatings or paint. The material is easily bent and formed, and there are no limitations on the length of copper sheet or strip because whole coils are treated on the production line, not just limited size sheets.
The Nordic Copper range includes Nordic Standard ‘mill finish’ and Nordic Brown pre-oxidised copper, offering lighter or darker shades of brown determined by the thickness of the oxide layer. The extensive Nordic Blue, Nordic Green and new Nordic Turquoise ranges have been developed with properties and colours based on the same brochantite mineralogy found in natural patinas all over the world. As well as the solid patina colours, ‘Living’ surfaces are available for each with other intensities of patina flecks revealing some of the dark oxidised background material.
Copper Alloys
But copper alloys are growing in popularity as well including Nordic Bronze and Nordic Brass – which can also be supplied pre-weathered. The innovative Nordic Royal is an alloy of copper with aluminium and zinc, giving it a rich golden through-colour and making it very stable. It has a thin protective oxide layer containing all three alloy elements when produced. As a result, the surface retains its golden colour and simply loses some of its sheen over time, as the oxide layer thickens with exposure to the atmosphere to give a matt finish.
All Nordic Copper products are suitable for internal applications, as well as exteriors. A wide choice of Nordic Decor mechanically applied surface treatments is also available for various surfaces and alloys, particularly suited to interior design.
Apart from traditionally-jointed, rolled material supported by a substrate, various other forms of copper for architecture are increasingly being explored by designers. For example, copper can be supplied in profiled sheets or extremely flat honeycomb panels, pressed to provide surface textures and modulation, or perforated, expanded or woven as mesh for transparency.
Whole-life Cost & Carbon Benefits
The lifespan of copper roofing and cladding can be regarded conservatively as 200 years, subject to substrate and structure, and this is endorsed by experience. Naturally, this longevity has a significant beneficial effect upon comparative whole of life cost and carbon assessments. Copper’s longevity is due to a complex patination process. It ensures extreme durability with no maintenance and resistance to corrosion in virtually any atmospheric conditions. And, unlike some other architectural metals, copper does not suffer from underside corrosion.
In addition, copper requires no maintenance or decoration. As a lightweight and flexible covering, structural support demands are reduced, resulting in lower carbon and ‘whole of life’ costs. Copper is also fully recyclable utilising long-established practices – 97% of copper in construction comes from recycling – and has other impressive sustainability and environmental credentials. And, of course, copper retains a high scrap value at eventual demolition.
Fire-safe Cladding
With an ‘A1 (non-combustible material)’ fire classification to EN 13501-1, Nordic Copper is suitable for cladding tall buildings, using appropriate constructions. Low thermal movement makes it appropriate for any climates and locations, and it is non-toxic and safe to handle, as well as non-brittle and safe to work. And, importantly today, its inherent antimicrobial qualities make it ideal for touch surfaces internally as well.