89 CATHEDRAL COMMUNICATIONS THE BUILDING CONSERVATION DIRECTORY 2025 MASONRY 3.2 where necessary to maintain and protect the original, or to enable the use of the historic building to continue. The basis for conservation should be continued attention to daily care, maintenance and management of the fabric and be aligned with the scaffold cycle. Maintaining the structural integrity of a stone element and functional weathering profiles should be the highest priority work when specifying a programme of stone repairs. Masonry with a consistent level of loss can be managed without major intervention if the weathering profiles are functioning and provided the pointing is appropriate and intact. The key is to establish at what point that collective loss will impact on the structural integrity of the stones and in turn the whole element, based on the rate of decay. Once this is established a decision can be made on the level of loss that will trigger a major intervention and the likely timeframe for that work. Masonry with variable levels of loss generally require more active and immediate response to reinstate the lost material with a local repair or new stone on a ‘like for like’ basis. There is always benefit in addressing poor quality pointing, repointing loose and open joints, and where the surface of a friable limestone is deteriorating, applying a sacrificial shelter coat of lime. Remedial works like these will always reduce the rate of decay to associated masonry. It is important to continue to monitor this work as further interventions will likely be necessary. PLANNING AHEAD Climate change as a ‘risk multiplier’ must be in the forefront of the mind of those charged with inspecting the condition of historic buildings and specifying repairs as environmental change is impacting on the way traditional building materials and building structures perform and decay. Changing weather patterns in the UK towards wetter, warmer winters and hotter, drier summers with more frequent and extreme storm events is hugely significant and makes the task of understanding the nature and rate of change ever more challenging. If the Met Office projections are correct for the UK climate in 2070, then those specifying conservation and repair work to high-level stone must factor in more rapid rates of decay, plan for more regular interventions, and a reduced scaffold cycle, giving cohesive access to historic fabric for repair, but also associated increased costs. Climate change will also increase the likelihood of trigger events occurring such as invasive ivy growth as warmer, wetter winters support vegetation growth through the winter months. The increase of frequent extreme flooding and storm events are more likely to accelerate loss to individual stones and pointing permitting deeper penetration of the weather into the structure and any ferrous metal fixings within. Consideration also needs to be given to the increased intensity of rainfall which is likely to overwhelm rainwater disposal and drainage systems at times. As well as considering whether the existing capacity of gutters and parapet gutters, down pipes and below-ground drainage can be increased, we also need to consider what happens to the overflow from extreme rainfall or where a system becomes blocked. The role of custodians of historic buildings to undertake the daily care of the fabric, deliver maintenance plans and act promptly to address trigger events as they arise is critical. The value of a ‘stitch in time saving nine’ should never be underestimated, particularly when you take into account the rising cost of repairs, the difficulties in finding skilled craftspeople, the challenge of fundraising and the need to work collaboratively with insurers. Equally critical is our need to maintain our focus on climate change and the global climate emergency. When tasked with the care of historic buildings, whether they are large complex masonry structures with elaborate ornamentation or a simple ancient stone monument, great weight should be applied to the ‘risk multiplier’ of climate change for those inspecting historic buildings and specifying conservation and repair work. Now is the time to revisit your stone policy in your conservation management plan to factor in climate change and plan for more frequent cycles of inspection and works to your heritage. CAMILLA FINLAY RIBA AABC is a director of Clews Architects (see page 15) and cathedral architect to Exeter and Worcester. She is also a member of the Cathedral Fabric Commission for England and a trustee of Historic Royal Palaces. Saturated masonry on the Edgar Tower at Worcester Cathedral, caused by the overflow from an undersized hopper and the maintenance problems posed by the complex pipework Masonry damage caused by water ingress and the subsequent expansion of rust on an embedded iron cramp
RkJQdWJsaXNoZXIy MzI0Mzk=