Stone fences, also known as flag fences or walls, slate fences or tombstone walls, consist of a single line of stones set vertically on edge. Most walling areas with suitable large slabs have the occasional example. These may represent the remnants of a more extensive system which was mainly replaced because, at only about 30″ (750mm) high, the fences were too low to contain modern breeds of cattle and sheep. In a few areas stone fences still form a significant part of the boundary system.
Generally stone fences are quicker to build and repair than dry stone walls. Very heavy slabs can be a problem, and a winch or other machinery may be needed to get them upright. Where long lengths of stone fence have assumed a ‘drunken’ appearance from years of neglect, the time advantage over dry stone walls is minimal, as it takes a long time to remove and re-site all the stones.
Sometimes a stone fence has a hedge planted alongside it, particularly alongside roads. This serves the same function as a ‘Galloway hedge’, with the stone fence protecting the base of the hedge, and the hedge adding to the height of the boundary. However, the roots inevitably tilt the flags so this is not usually a very durable combination.
Caithness flags
The flag fences of Caithness comprise the most extensive stone fence system in Britain. The flags are old red sandstone, usually 1.25-2″ (30-50mm) thick, and about 30″ (750mm) out of the ground. Unlike many other stone fences, the individual stones are overlapped and the top is very level. The overlaps vary considerably from 2-9″ (50-230mm), with about the middle of this range being the norm. The regularity of the stone makes this overlapping method relatively easy to build, and the overlaps provide mutual support for the flags.
The flags are set in a narrow trench about 12″ (450mm) deep, and then the soil is compacted back in thin layers. Shorter slabs are packed higher to give a level top. Slabs with less than 12″ (300mm) in the ground are not particularly stable, and are best sited between solid neighbours. Fences constructed entirely of shorter slabs are not recommended, as they soon tilt out of position.
Many Caithness flags have had fences added, either to aid stockproofing or to protect the flags from cattle damage. Square fence posts are driven in at about 10-17′ (3-5m) intervals on alternate sides of the flags, projecting about 6-8″ (150-200mm) above them, and supporting one or two strands of barbed wire.
Lakeland slate fences
Stone fences are also relatively common in parts of the Lake District along the boundary of the Silurian slates and the Borrowdale volcanics, where the Coniston and Brathay flags occur.
Some are simply overlapped using the angle of the edges, as shown.
Others have been carefully shaped so that the slabs interlock. This forms a stronger structure than the overlapping Caithness style, as the slabs cannot move in either direction. This interlocking is more prevalent on the older stone fences, presumably because of the time and skill required to shape the flags. More modern stone fences and repaired sections tend to have the simpler overlap. The tops show variation in level, from as low as 18″ (450mm) to over 30″ (750mm).
Other stone fences
In more urban settings thin sandstone flags can sometimes be found fastened with iron plates bolted on either side. Beddall (1950) describes such fences in the area of Rochdale and Todmorden, made of thin gritstone flags about 6′ (1.8m) high, 2′ (600mm) wide and 3-4″ (75-100mm) thick.
Isolated examples of stone fences are found where thick sandstone slabs occur.
This fence (above) stretches for about 450 yards (400m), although there are extensive gaps.
The fence at Stanton, Derbyshire is an unusually high stone fence, with the stones butted together, and the height maintained by balancing stones lengthways on the shorter uprights. This fence partly encloses a ridge and furrow field, indicating its age.
At Wycoller Country Park, near Colne, Lancashire, there are several stone fences which are thought to be the remains of 13th century ‘vaccary’ or cattle enclosures. Generally the slabs are of similar dimension to those at Overton, but there are a few very large slabs, 5″ (130mm) thick, 6′ (1.8m) wide, and about 36″ (900mm) out of the ground.
In North Wales many areas of slate, shale or mudstones have remnants of stone fences of varying height, with 2-6″ (50-150mm) gaps between stones, and frequently mixed in with sections of standard walling. The most common form though are the slate fences found in the slate mining areas of Bethesda and Corris. These comprise narrow slates spaced about 2-3″ (50-75mm) apart, and wired together at the top.
Originally the wires were fitted by twisting them together and then passing them around the next slate. For repairs, it’s easier to run two wires the whole length of the fence, and then twist them together between the fence with a stout piece of wood or similar, like a windlass. Occasionally the wires are simply woven between the slates, but the twisted method is stronger.
