A building stone audit for Kilmarnock : surveying, matching, and sourcing stone for the built heritage

摘要

Surveys of the condition of the stone masonry in twenty-five buildings and structures in theudJohn Finnie and Bank Street Conservation Area in Kilmarnock have provided information toudguide forthcoming grant-aided repairs and inform future maintenance strategies. Stoneudsamples from each surveyed structure have been characterised in order to identify the originaludstone types, and are matched to stone from currently active quarries to ensure that appropriateudstone is used for the repairs.udKilmarnock’s historic stone buildings directly reflect the local geology, providing a strongud‘sense of place’. The changing use of stone through time has contributed to the evolution ofudarchitectural styles that document different stages in the town’s history. The earliest buildingsudand structures used locally-sourced blonde sandstone with whinstone, probably obtained fromudnearby surface outcrops and boulders. Subsequently, better quality blonde sandstone wasudobtained from several town quarries, notably Dean Quarry which provided large quantities ofudstone in the first half of the 19th century. Once connected to the wider railway network, redudsandstone was imported from the Mauchline area, providing higher quality stone that enableduda more ambitious architecture in the second half of the 19th century, reflecting the increasingudprosperity of the town. Although red sandstone dominated from this time, a few notableudbuildings used imported blonde freestone for high quality ashlar and decorative work.udThe condition surveys show that the principal reason for damage to stone is waterudpenetration, leading to surface soiling (biogenic growth) and scaling of the masonry surface.udA major cause of water penetration is lack of maintenance, in particular failing rainwaterudgoods. Much of the damage is associated with exposed and projecting masonry elements suchudas cornices, string courses and sills, which require repair or replacement in order to protectudthe adjacent masonry and ensure long-term survival of the stonework. The use of de-icingudsalts on roads and pavements has caused considerable salt contamination to masonry atudground level resulting in disaggregation of stone. Damage due to previous stonecleaning hasudcaused loss of masonry details, significantly degrading the appearance of several buildings.udToday all of the original stone quarries that supplied Kilmarnock are closed. Petrographicudanalysis of the masonry samples has identified the closest matching stone types fromudcurrently available quarries throughout the UK. The best way of ensuring compatible stone isudto reopen the original quarries. Most of the original quarry sites cannot be reopened, so areasudof adjacent geology have been identified which could provide sites for the renewedudproduction of stone.udThe results from this study are intended to guide the repair of masonry and ensure thatudappropriate replacement stone is selected for repairs, as well as highlighting the importanceudof maintenance. This information is relevant to other buildings in Kilmarnock and theudsurrounding district, as well as the wider Central Scotland area. The reopening of stoneudquarries would provide a sustainable source of appropriate stone to ensure the conservation ofudthe built heritage in Kilmarnock and East Ayrshire.