SLATE AND STONE ROOFS IN ENGLAND
10/11/12
The vernacular slate and stone roofs of England have used a very wide variety of fissile or cleavable rocks ranging in age from Cambrian to Cretaceous. The physical and visual characteristics of these stones and the skill and ingenuity of roof slaters in adapting them to a range of weather conditions have made a major contribution to England’s built heritage and regional distinctiveness.
A review of these slates and stones was published by the English Stone Forum and can be downloaded free from the link below or the complete publication England’s Heritage in Stone can be ordered from the National Stone Centre Porter Lane, Middleton by Wirksworth, Derbyshire DE4 4LS 01629 824 833 price £8.00 plus postage.
These are the slates and stone slates. They are arranged by geological age with the oldest at the bottom.
Cambrian
Sandstone, limestone and slate sources
Sandstones
In the main, sandstones have been used for roofing in the more westerly counties of England from Bristol northwards. In the southeast, Horsham stone is an important source.
Limestones
Jurassic age limestones are a major source of stone-slates to the east of the sandstone sources. Permian age Magnesian limestone has also been used in the past.
Slates
Roofing slates used in England have predominantly been sourced from the Cambrian, Ordovician, Silurian and Devonian age rocks in the western parts of England and Wales. One other important source was at Swithland in Leicestershire.
Maps adapted from Cameron et al. Directory of Mines and Quarries, 2002. 6th Edition. British Geological Survey, HMSO, London and reproduced with permission
Late Jurassic and Cretaceous
Purbeck limestone Dorset
Horsham stone East Sussex
Jurassic: Inferior Oolite and Great Oolite groups
Collyweston ‘slates’ limestone
Stonesfield ‘slates’ limestone Lincolnshire
Early Jurassic: Lias group
Red Penrith Sandstone
Ham Hill stone Somerset
Permian and Triassic
Magnesian limestone (Cadby Formation) Nottinghamshire
Permian red sandstone Dumfriesshire
Ordovician
Swithland slate Leicestershire
Ingleton ‘slate’ North Yorkshire
Welsh Cambrian slates Gwynedd
Ordovician Welsh slate
Westmorland Green slate
South Shropshire sandstone
Devonian
Silurian
Carboniferous
Old Red Sandstone
Cornish random slates on the right are often inappropriately replaced with tally slates on the left
Carboniferous sandstones are usually very flat (left) but some show ripple bedding (right) Derbyshire
Carboniferous Pennant sandstone South Wales
Herefordshire sandstone
Burlington Blue slate Cumbria
Altered Hope Shale near Bishop’s Castle Shropshire
Harnage (Hoar Edge) ‘slate’ Shropshire
Harnage slate
Herefordshire sandstone on Dore Abbey
The Tilestones - Llandybi to Downton Abbey Shropshire
The geology is the vernacular. The dialect is the way the slater uses the stone.
Middle Jurassic:
Forest Marble Dorset, Somerset, Gloucestershire, Oxfordshire
