BCD SPECIAL REPORT ON HISTORIC CHURCHES 31st ANNUAL EDITION 15 UNDER THE WEATHER Storm damage repairs and mitigation Richard Martin AS BRITISH winters become warmer, they also become wetter. In the latter part of 2021 and early 2022, storms Arwen, Eunice and Franklin arrived in the UK and caused devastation to many cathedrals and churches. In one case, a carved, freestanding pinnacle on the tower fell, weighing approximately a tonne and consisting of 15 stones. It crashed through the vaulted transept below, luckily not causing injury to anyone. At another, a pinnacle that had withstood hundreds of years of British weather finally gave up and was left teetering at an angle of 45 degrees. Storm damage can cause immediate and obvious issues, such as debris falling from height. It can also cause damage with a less immediate effect through the dislodging of leadwork by high gusts of wind, the lifting of slates, the blocking of gutters with debris and the erosion of exposed masonry joints, allowing mosses and weeds to gain a hold. This leads to saturation of the fabric below and the destabilisation of stone, as well as providing an environment for larger vegetation growth, like buddleia and ivy. These are all examples of damage that may not be recognised immediately but can cause long-term issues for the building if not discovered in time. In the past it was usual to inspect stone details at height perhaps two or three times every 100 years, as the costs of erecting scaffolding and managing a large programme of works was a huge undertaking. In recent decades the use of drone surveys alongside repairs and surveys made using rope access and mobile elevating work platforms (MEWPs) such as ‘cherry pickers’ has enabled regular and timely action to take place, prolonging the life of exposed stone detail. As everyone in the conservation sector of the building industry understands, shedding rain and water management are the most important factors in the upkeep of heritage properties. Indeed many of the most glorious details on our historic buildings are there to shed water. Grotesque gargoyles, moulded arches, steep spires, carved cornices and peaked finials all direct water into well-designed drainage systems. In some cases those drainage details do require a rethink due to the increasing frequency of extreme weather. Variations from the original design may sometimes be necessary, and getting this right requires conservation architects, structural engineers, stonemasons and clients working together. The upkeep of rain shedding details and water management must be prioritised for the health of the building. Should the details fail and stone become loose, it will be necessary to remove the vulnerable parts from the building to prevent any accidents. If this is the case, the runoff water may then take a different course, other than the originally designed route and this can lead to a number of (Photo: Heritage Stone Access)
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