CONTEXT 180 : JUNE 2024 41 of the building. To complement the condition survey, it produced a set of outline proposals for more substantial future interventions. These included reroofing the most significant parts of Old Hall, or installing a temporary roof that could be deployed or retracted depending on the weather, with chainmail window coverings that could be removed in the summer but installed in the winter to keep out driving rain. Because the building is now a roofless ruin on the top of a hill exposed to the weather, the main source of decay is wind-driven rain. Almost every square inch of the fabric provided a range of justifiable repair approaches. The team assessed each repair knowing that a strict budget of around £1 million had been set. Along with replacement of the most decayed walling stones and repointing with hot-mixed lime mortar, the most significant interventions were the reintroduction of external lime render (or harl) to the west elevation; new enlarged lead canopies over the decorative plaster; renewal of the 1990s public viewing platform; extensive replacement of window mullions, jambs and transoms; and specialist conservation of the decorative plaster overmantels. The most radical conservation technique employed was the reinstatement of the external lime render to the west elevation of Old Hall. The west elevation, sitting high on the cliff edge, is fully exposed to the prevailing weather. The original lime render had largely fallen away long ago, although numerous patches of the basecoat survived in situ. The now exposed soft sandstone has significantly eroded to the extent that the internal chimney flues have become exposed in places. This 20-metre wall also provides the backing substrate for the most significant of the decorative plaster reliefs: Gog and Magog within the Hill Great Chamber. This had been subject to continual moisture movement through the external masonry wall and subject to structural movement undermining the key between the plaster and sandstone. Reinstatement of the lime render was preceded by structural repairs to the wall by rebuilding voids and replacing heavily eroded stones with new and dubbing-out of the deeper undulations. Primarily providing a protective coating over the masonry, the second beneficial aspect of the render is that it will encourage rainwater to spread around the more porous lime over the surface of the building, rather than penetrating into the stone structure behind. The original external lime render was analysed, and the proposed lime render mix was formulated to match the existing as closely as possible with a limewash finish. The new lime render does not try to recreate the original smooth-coated finish; the technical performance was prioritised over any goals of authentic reinstatement. It was agreed to apply a harl (thrown application to achieve a rough cast appearance). This decision was taken for a few reasons: • The new harl remains visually similar but subservient to the historic fragments of original plaster which had lost their outer coat layers. • It differed aesthetically from the low-level fragments of internal plaster that remained on the west elevation where structures had been removed historically from the base of the wall. • It allowed for a greater surface area to encourage faster evaporation of rainwater. • It kept the additional weight of the intervention to a minimum on the historic structure. The conservation philosophy for the project aligned with best-practice SPAB principles for sensitive repair. However, the SCAMP principles led to interventions being prioritised at a higher level over the low-level repetitive activities. For example, defrassing, pinning, indents or full replacement were favoured for any failing stone to ensure longevity, and mortar repairs were avoided. Historic SPAB repairs were retained where possible and new clay tiles repairs were minimised, with preference for stone replacement. This was so it would not confuse the evidence of the 1912 SPAB repair works and not to set a precedent for large areas of the building becoming terracotta rather than stone. The site reopened to the public in August. Dorian Proudfoot, a conservation accredited architect and director of Donald Insall Associates, has been a lead consultant at Wentworth Woodhouse and Hardwick Old Hall. Tom Bromet is an associate at Donald Insall Associates with an interest in cultural continuity through adaptive reuse and new build. Far right: Failing decorative plaster, formerly internal, now exposed to the elements Plasterwork on the west wall of the Hill Great Chamber showing giant figures on the overmantel which may represent Mars and Hercules
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