Aesthetics, performance and buildability

Jonathan Lowy of VMZinc discusses what architects should be looking for when specifying zinc, and its long-standing attributes ranging from aesthetic appeal to maintenance, durability and recyclability

If you’re like me, then working from home – or should that be living at work – is the new normal. However, this is not the case for those actually constructing buildings and in particular installing zinc roofs and walls. In a creative industry such as architecture much can be done via a screen, but there are undoubtedly limits in what is possible online. Sketching, mock ups and making maquettes fortunately still have their place not only in design, but also in training and further education.

Since the first zinc roof was installed in Liege in Belgium in 1809, the craft of the installer has been critical to both the beauty and performance of a zinc roof or wall. At a time when less academic forms of education are again being championed, a skilled zinc installer is a vital asset to any project where zinc has been specified. While companies play a large role in training, this can be supplemented by Basic Competency Programme training and Specialist Applied- skills Programmes in zinc which includes 30 days of off-job but hands-on training. A further 18 months of apprenticeship can lead to a Level 3 NVQ Diploma in Heritage Skills metal roofing. Installers who have followed this type of training, are capable of installing almost any zinc roof or wall that has been dreamt up on or off line!

Buildings of all uses that are clad in zinc vary greatly, from small to large, curved to angular, and simple to complex. The aesthetic appeal of zinc is always important but so is the limited maintenance, durability and recyclability at the end of the service life. A correctly designed and installed zinc roof or wall has a service life of 100 years following the BRE Environmental Product Declaration EN15804. In this brief article, we will not go into how European Norms may be affected in the coming months and years, but currently they are still used by the UK’s Building Research Establishment. The 100 year service life also only requires very limited maintenance, as the best way to keep a zinc roof looking great is for rain to fall on it. However, all good things come to an end, and at the end of a long life, zinc is 100 per cent recyclable and indeed close to 99 per cent is actually recycled.

One of the more traditional projects completed in the last few years was at Poundbury in Dorset where Quinlan and Francis Terry Architects designed, amongst other buildings, the Duchess of Cornwall Inn. The project not only includes a number of decorative dormers but also a zinc balustrade. Pre-weathered zinc was chosen for a number of reasons; the low weight of zinc when compared to stone or even lead meant that the supporting structure did not have to be quite as large, and the material’s malleability and as always its aesthetics were also critical to the choice. Finally, whilst the building does have Palladian inspiration it is also reminiscent of Parisian buildings associated with Baron Haussmann, where stone facades often combine with slate and zinc roofs.

Now for something very different indeed. Right next to Wembley Stadium in north west London, White Ink architects designed a residential project called South West Lands. Brick, balconies and red pigmented pre-weathered zinc combine to create a building with a distinctive warehouse feel. Due to the residential nature and height of the building it was critical that the facade, including the standing seam zinc panels, was composed entirely of materials with limited or no combustibility (A1 or A2 following EN13501-1).

Zinc is not only used on large buildings but also smaller projects, an excellent example being the RIBA House of the Year 2019 – House Lessans designed by McGonigle McGrath Architects. The house is built in the rolling County Down landscape on a site previously occupied by old farm buildings, some of which have been re-used, and the pitched roofs and walls in pre-weathered zinc reflect some of these buildings’ materiality.

Finally, zinc can and is used on some very avant-garde projects. In Krems, Austria on the banks of the Danube, Marte and Marte Architects used engraved zinc shingles to clad an art gallery in the form of a revolving cube. While the site is in a UNESCO World Heritage Site, the Krems Art Gallery continues the Austrian trend of architectural innovation in old town centres with the House of Music in Linz and the Kunsthaus in Graz being other well known examples.

To summarise, zinc does need good design and high quality installation, but it can be used on a large array of building types in many architectural styles to form not only attractive but highly sustainable roofs and walls – while remaining very cost-effective.

Jonathan Lowy is operational marketing manager at VMZinc