Revitalising Collyweston limestone slate production by artificial freeze/thaw splitting. (20th January 2018)

• Record Type: Journal Article
• Authors: Laycock, Elizabeth Anne; Jefferson, David; Hetherington, Steven; Clegg, Francis; Wood, Christopher
• Is Part Of: Construction & building materials. Volume 159(2018)
• Page Start: 486
• Page End: 498
• Publication Date: 2018-01-20
• Subjects: Limestone -- Roofing -- Slate -- Stone -- Mining -- Conservation -- Freeze/thaw -- Vernacular building material -- Collyweston -- Tilestone; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2017.10.039
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: Extraction of Collyweston limestone 'slates' (tilestones) from the Roman period on. Various factors influence the efficacy of splitting including the block ('log'). Important factors: morphology, size, time since extraction and freeze/thaw regime. Commercial production of tilestones is possible by artificial freeze–thaw processes. Abstract: Extraction of limestone roofing slate from Collyweston was an industry which was considered extinct by the early 1990′s, with building repairs relying on wholesale recycling of roofing from demolished buildings. Traditionally stone extracted from the mines was exposed to natural cycles of freeze/thaw to facilitate splitting. Work was undertaken over several years to investigate the resources available and whether these could be artificially frozen to produce slates. The work identified a freeze/thaw regime which could be used to produce roofing slates for historic buildings and which were used in the Historic England restoration of Apethorpe Palace. Mining of the Collyweston limestone stone has now resumed and uses artificial freezing to achieve production of slates which is economically feasible due to the faster process time.