Performance through time
Jonathan Lowy of VMZinc looks back at how changes in technology have improved the manufacture of zinc over the decades to enable greater versatility and durability in today’s projects
Notre Dame Cathedral in Saigon (now Ho Chi Minh City),Vietnam, as well as many other parts of the world. Prior to the second half of the 20th
century – while highly skilled installers created technical documents showing how zinc could be installed using techniques such as batten cap, flat lock wall panels and even sine wave panels – the actual standards pertaining to the zinc itself were somewhat limited. Over the last 50 years, the technology
used – not only to refine but also roll zinc – has changed considerably. Initially a factory in Viviez, southern France built the first electrolysis hall in 1922, thus allowing far purer zinc to be produced. This has now become Special High Grade Zinc BS EN 1179. This plant still exists and supplies the majority of pre-weathered zinc used in the UK and Ireland. By using SHG BS EN 1179 and combining it with small amounts of titanium and copper, the modern BS EN 988 alloy was created. This zinc not only contains no toxic impurities such as cadmium, but is also more resistant and allows easier continuous rolling, enabling manufacturers to produce large coils. Before the 1970s, all zinc sheets were only two metres in length. The coils produced by the continuous rolling process allow long sheets to be used with 13 metres being a standard maximum, although on some very specific projects this has been exceeded.
century Baron Haussmann made zinc ‘the’ roofing material of Paris and the metal’s use extended to the UK, USA, Japan and even
T
he first zinc roof was installed on St Bartholomew’s Church in Liege, Belgium in 1809. Over the coming
Durability & sustainability BS EN 501 and Code of Practice 143-5 address traditional fully supported, vented zinc roofing and wall systems. However, over recent years designers have requested a little more third party accreditation. An example of this is durability. For many years it has been known that a zinc roof can last over 100 years, and there are case studies to demonstrate this. Zinc is also a material that is easy to recycle. The BRE EN 15804 Environmental Product Declaration is a way for designers
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36
