Jonathan Lowy of VM Zinc traces the architectural history of zinc, from its European origins to a modern role in durable, sustainable building envelopes.
In 1811, a roofer in Liège tried something radical; he installed the world’s first rolled zinc roof, adapting techniques from lead work to a lighter, more adaptable metal refined by the abbot-chemist Jean-Jacques Dony.
The financier, François-Dominique Mosselman, soon recognised that a material is only as powerful as the ecosystem behind it. He invested in mines, rolling mills and in 1837 helped found a company whose name echoed the ore itself: La Vieille Montagne, “the Old Mountain.” The new company was able to supply this ‘new’ metal at a much larger scale, therefore allowing far more ambitious projects to be specified
in zinc.
Paris, redrawn in zinc
If Liège proved to be the beginning, Paris proved to be the destiny. Under Napoleon III, Baron Haussmann rebuilt the city in the 1850s, changing the city from bottom to top literally in terms of zinc, by imposing large-scale buildings whose roofs featured the famous mansard frames, which were more cost effective than the former steeply pitched tiled roofs, making zinc a huge success.
The mansard became a civic model: break the roof into slopes, crown the boulevards in light. Zinc’s high strength to weight ratio and workability made it the natural answer, lead was heavy, copper expensive; in 1862 a decree requiring rainwater recovery on street facing facades mainstreamed zinc gutters and rainwater goods.
A micro-state that powered a material
Supply is a design story, too. After the 1815 Congress of Vienna, the Altenberg (Vieille Montagne) mine found itself inside a geopolitical curiosity: Neutral Moresnet. In the vicinity of Kelmis (50 km to the east of Liège), the site of a large zinc and lead mine, the Netherlands and Prussia did not manage to reach an agreement. After multiple discussions, a special contract called “the borders contract” was signed in 1816. It was decided that the commune of Moresnet would be divided into three parts. The village went to the Netherlands, and the territory corresponding to present-day Neu-Moresnet became part of Prussia. The remaining part, around Kelmis and its zinc mine, was attributed a neutral status. Administered jointly, it became both an engine room and a social laboratory. The company funded a school in 1857, provided medical care, enabled loans for housing; low taxes and decent wages drew skills, stability and, by extension, quality. For a century, this tiny territory fed an outsized architectural impact before neutrality ended in 1919.
A global envelope material
In the middle of the 19th century, zinc roofs started to spread beyond Belgium, France and Germany and an example of this was Liverpool Central Library that was completed in 1879 with an attractive zinc dome. After over 130 years of service, the zinc was replaced, and will hopefully last well into the 22nd century.
In the 19th century, architects only had mill finish natural zinc on offer but in 1978 the first pre-weathered zinc was produced and even though zinc has always been extremely durable modern industrial methods give the metal an even higher performance with this being detailed in BS EN 988. The BRE’s Environmental Product Declarations also give a service life of 100 years, and while zinc is 100% recyclable, over 98% is actually recycled in Western Europe. To add to this, pre-weathered zinc is also A1, non-combustible in accordance with EN 13501-1.
How are architects using zinc?
The wide variety of pre-weathered zinc now available, coupled with an extensive range of systems, makes zinc an ideal choice for building envelopes. Evans Vettori designed a jewellery centre for CW Sellors. The project combined a number of materials, including QUARTZ-ZINC standing seam roofing and facades installed by Just Hard Metals. The Urban Agency used the same standing seam panels on the White Water Rafting centre in Dublin. The striking red panels were installed by Copeland Coppersmith. Returning to Natural zinc, The Manser Practice specified this product on this low level ferry terminal, with the standing seam panels being installed by Longworth Hard Metals.
The New Teaching and Workshop Buildings at Oxford Brookes University by ADP combine traditional fully supported systems,such as standing seam roofing with rainscreen facades, including perforated screens, with all of the systems being in Pigmento green zinc.
The next chapter
‘Covering Generations’ is a fitting phrase for what zinc has always done: it covers towns and cities generation after generation, and it also spans generations of craft, as we have seen from the zinc roofers of Paris receiving UNESCO world heritage status. From a Liège church roof to Parisian boulevards and onto today’s rainscreen facades, the material’s promise remains the same: make the building’s envelope durable and attractive.
Jonathan Lowy is operational marketing manager at VM Zinc