Copper’s unique architectural qualities are defined by its naturally changing patina – which cannot be successfully replicated using other materials with surface coatings. 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 then result in development of the distinctive green patina – or blue in coastal locations.
The Anzeiger-Hochaus, Hannover (above) – built in 1928 and 51m high – is a unique example of German skyscraper construction. The 2019 renovation included complete replacement of the original copper dome (shown here) with new Nordic Copper Special Patina (opposite), meeting strict listed building protection.
Pre-patinated Copper Naturally
All these naturally developing surfaces can be provided straightaway with the ‘Nordic Copper’ range. The factory processes involved are generally similar to those taking place over time in the environment utilising copper mineral compounds, not alien chemical processes. The surfaces form an integral part of the copper, generally continuing to change over time, and are not lifeless coatings or paint.
The extensive Nordic Blue, Nordic Green and 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.
Suomitalo is a major, unique office building in the heart of Helsinki dating back to 1911. Its complete roofscape has been replaced using Nordic Copper Special Patina to match the original material which has been recycled for new applications.
Repairing and Replacing Original Copper
With Nordic Copper Special Patina, unique pre-patinated copper material can be produced to match naturally patinated copper, especially for historic buildings. An original sample from the building is used but initial development can be started with the help of a Special Patina Tool (which can be downloaded and printed). The card is simply placed on the original copper surface and photographed. Once a specific patina mixture has been established and product supplied, the project mix is retained in case of follow-up orders.
Aurubis can also recycle the original copper removed from a project. All our architectural copper products are manufactured using 100% recycled raw-material. Copper’s ability to be recycled repeatedly, without any loss in performance, is an important sustainability benefit. Aurubis is part of the world’s leading integrated copper group and largest copper recycler.
Suomenlinna Church, built in 1854, is Unesco world heritage listed. The master tower – which doubles as a lighthouse – is particularly important on the Helsinki skyline. The new Nordic Copper Special Patina dome was made by recycling the original copper.