16 CONTEXT 185 : SEPTEMBER 2025 especially in very exposed areas, as can be seen at the Arnol Blackhouse. Every aspect of this construction was highly regional and developed in accordance with the needs of the location, giving a distinctive character to the local area. For example, in the Western Isles marram grasses would be gathered locally from sand dunes, and properties surrounding the Tay reed beds, once they were established, would have harvested this reed. Sourcing sufficient material sustainably and avoiding ecological impacts requires careful thought and management. Over time thatched roofs started to be replaced. Thatching was labour intensive, the materials became harder to source and were relatively short-lived, and expertise held by the community that enabled them to repair and rethatch roofs was lost. Other, simpler practices started to become more available and affordable, and they became more popular. Many of these roofs therefore changed over time and were eventually covered, often by corrugated iron. However, in some instances, such temporary coverings allowed for the roofs to retain their older layers underneath, providing a fascinating record of changing materials and practices, and telling us the story of the surrounding land over time. It’s all in the details The changing UK climate means that we need to consider the detailing of our roofs and associated rainwater goods more carefully than ever. Excessive rain is already causing damage to many of our traditional buildings, and a wellmaintained roof is one of the most fundamental ways to protect the long life of a building. This may mean that some additional detailing needs to be considered, but on a property-by-property basis to get the best outcome. The junction of the roof and gable can be a weak point for water ingress. Historically, detailing helped divert water away from the gable. Ideally skew copes should have a good margin projecting over the wall, with a drip detail on the underside to control the shedding of the water away from the gables. Traditional roofs often have skew putts, grooved channels carved into the lowest section of the skew copes, and on slate roofs, slates at the verges may have a notch taken out of the corner. These features all act to divert water away from the corner of the building and towards the slates or tiles. This helps to protect the masonry, and any lime finishes below, from water run-off. Carefully detailed leadwork can also do a great deal of the heavy lifting to ensure that a roof expels water in the most effective way possible. When applied by a skilled leadworker, lead detailing can last for many decades. However, with the increasing rainwater, some of these features need to be adapted to provide deeper downstands and bigger laps, and so on. Functional designs that would once have easily managed our climate are being challenged more and more regularly. In Scotland for example, secret gutters regularly overflow and are increasingly difficult to maintain. The lack of maintenance of roofs can be seen right across the UK. As we have become more removed from the knowledge of how our buildings were designed to function, tasks such as checking gutters and repairing slates are often forgotten. In Scotland, lime-mortar skew-fillets would traditionally have been limewashed regularly as part of a routine maintenance cycle, and without this an extra level of weather-proofing is gone. A lack of regular care prevents roofs from functioning as the water-tight hats that we expect. This risks traditional roofing materials being blamed for the inevitable leaks that follow. Investing in and developing skills and education in the maintenance and repair of our roofs is vital if we are to retain our beautiful and distinctive roofscapes. Thatch at Arnol Blackhouse (Photo: Crown Copyright, HES) Madeleine Clark is a technical officer in the technical conservation projects team at Historic Environment Scotland. A Scottish roofscape (Photo: Crown Copyright, HES)
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