31 Zinc: the natural choice Jonathan Lowy of VMZinc says the history of zinc specification aligns with its future
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hen zinc was first used as a roofing material at the beginning of the 19th century many of the reasons for its choice all that time ago are still relevant today; availability of the metal, the technical advantages of the roofing systems and the attractive aesthetic of the material.
Zinc was first extracted and rolled in
Liege, Belgium in 1809, and while this factory has long since closed, zinc is still refined and rolled in western Europe making it an easily available material. In 2024 the majority of zinc used for roofs and facades in the UK and Ireland was produced in France and thus has a relatively low carbon footprint due to the makeup of France’s electricity supply. An added attraction is the durability and recyclability of zinc. The BRE gives zinc an expected life of 100 years with over 98% recycling of the zinc roof panels at the end of this long life. Furthermore the maintenance of a zinc roof is little more than clearing out the gutters annually. Environmental Product Declarations for zinc in accordance with EN 15804 offer a more in depth view of the metal’s performance.
In the early days of zinc roofing the ADF OCTOBER 2024
batten cap system was used, not dissimilar to a lead roll but in recent decades the standing seam system has become more popular with its ability to cover complex shapes and surfaces with slopes as little as 3° all the way to walls and even soffits. This makes it a material and approach that is truly for the whole building envelope. For facades the choice of system is vast and includes traditional fully supported panels such as standing seam and flat lock panels as well as a wide range of rainscreen cassette systems.
Zinc should not be confused with galvanised steel, which is simply steel protected with a very thin layer of zinc or painted metals where the paint either protects the metal beneath and/or enhances the substrate’s aesthetics. Metals such as zinc and indeed copper are used both for their inherent beauty and durability as solid non painted metals. It is possible however to chemically modify the surface of zinc thus changing the metal’s aesthetics and pre-weathered zinc has now been available since 1978. This form of zinc remains solid and is non-coated.
A further advantage of zinc roofing and cladding is the relative lightweight of this
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The BRE gives zinc an expected life of 100 years with over 98% recycling of the zinc roof panels at the end of this long life
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