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RCI Feb 2018

CLADDING & SHEETING Copper alloys have grown in popularity as a cladding material over the last few years, as more designers seek out its aesthetic, durability, longevity and low maintenance properties. Copper alloys include brass, bronze, gold-effect and Zinn, all of which can be enhanced with a range of prepatinations and surface treatments. Bronze age Bronze remains a popular choice as a cladding material, principally because of its unmistakable aesthetic properties which have an ability to stop people in their tracks in admiration. Over time, the material continues to develop and embellish these aesthetic qualities by taking on subtle, earthy, brown-red to brown-grey tones through the natural weathering process. Being an alloy of copper and tin, bronze provides the façade with outstanding mechanical abrasion and corrosion resistance properties that mean it, along with all other copper alloys, is one of the most durable cladding materials available. The east side of the 10,000m² Emily Wilding Davison Building at Royal Holloway, University of London, features the brown-red to brown-grey and ochre tones of our TECU Bronze cladding panels. Specified by Associated Architects, the cladding panels are made using an aluminium honeycomb core for strength and rigidity, structurally bonded between two thin gauges of bronze material, to create an optically flat face with tight radii. This cladding is then fixed to composite panels that incorporate high levels of insulation. The subtle colour variations of the bronze façade on the Emily Wilding Davison Building help it sit harmoniously in a site steeped in history, flanked on one side by the Grade I listed Gothic revival building, and surrounded by one of the most beautiful natural campus landscapes of any university in the world. Where there’s brass Another copper alloy that has the ability to transform an ordinary rainscreen façade into something extraordinary is TECU Brass. This is created by blending copper and zinc, which again creates an extremely tough, robust façade that subtly changes from its initial golden colour as a result of the natural weathering process. Initially it will develop a matte finish on the surface before taking on mellow brown tones that continue through to a deep, rich anthracite. A great example of the visual effect that can be created by specifying brass with a surface treatment was demonstrated at the RIBA award-winning 35,000ft² JW3 Jewish Community Centre in London. The architects 040 FEBRUARY 2018 RCIMAG.COM specified our TECU Artisan Burnished Brass to create the solid rainscreen base to the lower ground floor of the building. Perforated singleskin Proteus SC panels were installed, while outside full-length glazing screen elements were used for the first and second floors. What works particularly well on this project is the way that the subtle natural colours of the artisan burnished brass panels complement the muted tones of the buff London brickwork. Another example of the ability of surface treatments to embellish brass can be seen at Imperial College’s new Molecular Sciences Research Hub in London, designed by Aukett Swanke. We again supplied the perforated panels in brass with a Capisco patinated finish to create a dynamic aesthetic that visually elevates the flat bare concrete façade and glazed elements. Going for gold More visually striking copper alloys are being developed to keep pace with the desire by clients for buildings that stand out from the crowd. Chamberlayne Road in London is a good example of this, with TECU Gold, recently installed as shingles. This is a relatively new copper alloy in the cladding sector, which is a mix of copper and aluminium. As with all copper alloys it is a very workable material, allowing it to be manufactured as a perfectly matching façade system including cladding, screening, soffits, reveals and roofline. Again gold offers outstanding mechanical abrasion and is highly corrosion-resistant and durable. The initial gold appearance of the façade will gradually oxidise following installation, forming a warm golden surface. If you or your client are looking to achieve the ever popular grey tones on a building design, TECU Zinn is an excellent choice. The material is a tin-plated copper that offers all the advantages of copper, but weathers from silver to subtle grey tones. Zinn cladding panels are highly suitable if you require a neutral backdrop that highlights other flashes of colour, for example, in window reveals or entrance areas. Surface finishes In order to shorten the timescale for achieving the subtle muted tones on a brass or bronze facade we often suggest choosing a prepatinated finish. This is where the oxidised layer is applied before the cladding panels leave our factory, bypassing the gradual development of the earthy tones through natural weathering, resulting from exposure to atmospheric conditions once the façade is installed. Specifiers and designers like it because it creates subtle colour variations from the day it is installed, just as you would get from the natural weathering process over an extended time. Brass and bronze copper alloy materials are also available with a range of different surface treatments such as BMA (Brass / Bronze Metal Antique), Artisan Burnished, Mid Brown Distressed, Metropolitan, Black Florentine and bespoke finishes from Capisco and Bronze Restoration. The decision to design buildings using cladding systems made from copper alloy materials provides a vast scope of opportunities for architectural creativity. Their striking natural, ever-changing surface appearance creates one-off designs that simply aren’t possible with some other cladding materials. Add to this, the freeform design possibilities of pre-patinated, burnished, brushed, distressed and BMA surface treatments, and you have everything needed to help your client create a building that comes to life and grows even more beautiful over time. www.proteusfacades.com The rise of copper alloys Simon Gregory, sales manager at Proteus Facades, looks at why there is growing interest in copper alloys as a rainscreen cladding material JW3 Jewish Community Centre Proteus Chamberlayne Road project


RCI Feb 2018
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