34 CONTEXT 185 : SEPTEMBER 2025 IMOGEN SHAW and GRAHAM BRIGGS Sourcing Scottish slate in the 21st century Slate quarrying in Scotland did not cease due to a lack of available material: there are plenty of suitable sources for roofing slate with the potential to be redeveloped today. Scottish slate is a quintessential part of Scotland’s traditional built environment, once widely used for roofing due to its durability and ready availability in many locations. Typically smaller in size, thicker and more variable in colour than slates found in England and Wales, the prevalent use of Scottish slate imparts a unique character to traditional roofs throughout Scotland. At the industry’s peak in the 19th century, these slates were exported as far afield as the USA, Australia and New Zealand. Despite this pedigree, no roofing slate has been quarried in Scotland since 1965. The Scottish slate roofs that remain are increasingly in need of partial or full replacement as the slates reach the end of their lifespan. As such, the dearth of supply of new Scottish roofing slates, and the dwindling availability of reclaimed slates from re-roofed or demolished buildings, poses an ever-increasing threat to Scotland’s built heritage. Recent work by the British Geological Survey (BGS) and Historic Environment Scotland (HES) seeks to tackle this problem, finding that several disused historic slate quarries in Scotland have the potential to supply roofing slate once more1. Types of Scottish slate Geologically speaking, three different types of slate have been quarried for roofing in Scotland: West Highland Slate, Highland Border Slate and Macduff Slate. Other stones, including the greywackes of the Scottish Borders, and the flagstones of Angus, Caithness and Orkney, were also quarried for roofing tiles, but these are not ‘true slates’ in the geological sense. Slates are often known by the name of the local area from which they were sourced (such as Ballachulish, Aberfoyle and Foudland Slates). A traditional Scottish slate roof, laid in diminishing courses (Photo: British Geological Survey, UKRI) 1Everett, PA and Shaw IR (2024) ‘Development potential for building stone resources in Scotland’, British Geological Survey Open Report, OR/24/020. Available at nora.nerc.ac.uk/id/ eprint/537904/ The contrast between a roof with Scottish slates (left) and another which has been re-roofed with imported slates (right) (Photo: British Geological Survey, UKRI)
RkJQdWJsaXNoZXIy MzI0Mzk=