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Zinc Key to Heritage Restoration

Tuesday, June 14, 2011 by VM ZINC®

Among the many heritage refurbishment projects being undertaken by traditional metal roofing contractors, VMZINC is now providing specialist advice to a growing number of architects. Experience drawn from regular restoration work using zinc throughout Europe has led to the company supplying materials for projects such as St Mary's Church Plas Power and the highly acclaimed Clapham and Sheffield Bandstands.

St Mary's Plas Power is of late 19th century construction and still owned by the Fitzhugh family. As the last remaining privately maintained chapel in Wales to hold regular services, Heritage and CADW funding was obtained to replace the original zinc roof and rainwater system, dating from 1875. Use of pre-weathered zinc not only captured the style of the decades old patina but provided a colour which will continue to age normally.

By contrast, the £1.2m refurbishment of Clapham Common's Grade II listed bandstand involved VMZINC in the manufacture of a bespoke, 62-section natural zinc roof and central finial. Designed by Thomas Blashill, then architect to the London County Council, it was erected in 1890 and is believed to be the largest of its type remaining in the UK.

In 1995 it had been placed on the English Heritage greater London buildings at risk list but had fallen into serious disrepair. Some of the factors affecting zinc's specification by architects Dannatt Johnson were its resistance to corrosion, weight and the ability to meet a highly complex roof design.

The 1:1 roof replication was undertaken, manufacture being divided into sections for cutting and shaping. Plaster prototypes were also used to create drilled sections and to design the punching moulds. A finely crafted curved wooden structure was built to support the zinc covering and the end result is an exceptional illustration of zinc's versatility.

Renovation of the derelict Grade II listed Victorian bandstand in Weston Park, Sheffield formed part of a £2.7m Heritage Lottery funded project to create the city's first municipal park.

It is again thought to be the only surviving example of such a design, VMZINC's 0.8 gauge natural zinc having been fitted using sliding caps, one of the earliest techniques for constructing a zinc roof. The material was laid hollow, supported by timber boarding, and wired to the wrought ironwork frame. Archive photographs were used to ensure all original detailing was accurately replicated. Work was carried out to English Heritage Best Practice standards for conservation and restoration, with components being hand crafted.