Dry stone walls are walls that are made without the use of mortar or cement.
They have been used as boundaries throughout Britain for centuries, and are a particularly important and attractive feature of the Cotswolds National Landscape. These walls are very much a part of what makes the area special. There are around 6,000km of dry stone walls across the Cotswolds. Sadly, many of them are in a derelict state, but steps are being taken to maintain and restore them for future generations.
History
The earliest known example of dry stone walling in the Cotswolds can be found at Belas Knap, a Neolithic long barrow built about 2000 BC near Winchcombe in the north Cotswolds. Most of the dry stone walls we see now date from the 18th and 19th century, when large tracts of open fields and downland were enclosed for livestock. Stone and labour were both readily available, so walls were relatively cost effective to construct. In the second half of the 20th century, many walls became redundant as livestock numbers fell and fields were used for growing crops. There were also fewer people employed with the skills to maintain and restore the walls. Dry stone walls, like many traditional crafts, can only be made by hand – so those which remain are a valuable reminder of the time, effort, and skill which went into building them.
Wildlife
Dry stone walls support a vast array of wildlife. Many species of lichens and mosses, such as feather and cushion mosses and algae, make their homes on walls. Some of these create ‘tilth’ (which comes from the oolitic limestone creating a soil like material) which supports other plants, including pennywort, stonecrop, cranesbill, and ivy. Care should be taken that ivy does not destabilise the wall.
Other plants found on the walls include spleenwort, polypody and wall rue, as well as some that have come from domestic gardens, such as species of saxifrage.
Slowworms and invertebrates including snails live within the walls’ nooks and crannies, as do spiders, woodlice, springtails, millipedes, bees, and wasps. One particular species of snail, Lauria semproni, can only be found at a single location in the Cotswolds. Adders and lizards can often be seen basking in the sun on the walls. Birds such as coal tits, wrens, wheatears, robins, redstarts, and little owls also make their nests within the cavities of walls, as do toads, voles, field mice, shrews, hedgehogs, and bats. Dry stone walls help to create microclimates that support other species that live nearby. The uncultivated strips of land running alongside walls are very important habitats for wildlife – like hedges, walls act as wildlife corridors.
Geology
Stone used for dry stone walling in the Cotswolds comes from thin strata of oolitic limestone. The thickness and colour of the stone varies considerably throughout the area. As a result, the appearance of the walls also varies. In the north of the Cotswolds, the stone can be honey coloured, while in other parts of the Cotswolds it can be grey or white. Near Bath the stone has a boulder-like appearance. A type of stone that is commonly found in walls across the Cotswolds is ‘Ragstone’, a particularly uneven, rough-looking stone.
Characteristics of Cotswold dry stone walls
Cotswold dry stone walls are built with a tapering cross section (called the batter). The width of the wall below the coping stones should generally be half that of the base. Through stones are used to bind the two sides of the wall together and small stones or ‘hearting’ are used to fill in the gaps of the stones on each course. The longer edge of each stone is placed going into the wall to protect the stone from weather effects. Each stone should be placed at a slight angle so that water can run out of the wall rather than staying within it. This is because retained water causes problems when it freezes and expands, damaging individual stones and even pushing walls apart over time.
Methods of topping walls
Various methods are used to finish off the top of walls. In the Cotswolds, so-called ‘cock and hen’ coping stones are the most common. These are thin individual pieces of stone placed on end at right angles across the top of the wall. These stones weigh down the courses below and bond both faces together so that the wall settles into a solid unit. They protect the face stones and fillings from the weather, animals and people.
Without copings, walls tend to flake away course by course, especially if they are made of small or fissile stones. Some walls are topped with dressed stones or stone slabs. Coping stones are sometimes cemented to the top of the wall to stop them from being dislodged by people or animals. This can restrict the natural movements of walls as they settle over time. In some areas of the Cotswolds rather than coping stones, it is not uncommon to see a layer of mortar, as a cap, spread over the top of the wall. The use of mortar in this way also restricts the movement of the wall and can result in large sections collapsing as one.
Features of Cotswold walls
Features in the dry stone walls in the Cotswolds contribute to the diversity of the area, and reflect local history. Walls contain many unusual features, including holes for livestock to pass through, stone steps, water troughs, stone styles, archways, and bee boles – a shelter within the wall where beehives used to be kept.
In some places the core of old stone pipes, saddle stones, and other reused stone artifacts can be seen in walls. Some local features are constructed in dry stone walling for example animal pounds used to hold stray livestock until they were collected by their owners. Walls were also used to partition dew ponds, watering holes for livestock, which owners sometimes shared.
Looking after these unique features
In the context of modern farming practice dry stone walling is expensive to maintain. Within the Cotswolds they are a unique and distinctive feature of the landscape and their conservation and management is a high priority. If dry stone walls are properly maintained they can last for generations. Some simple steps will help ensure that the walls remain in good condition:
- Cut vegetation from the side of walls once a year. This will allow the wall’s condition to be checked and will prevent the growth of woody vegetation. It will also ‘air’ the wall and help prevent frost damage.
- Do not allow trees to grow beside walls. Their roots can make foundations unstable and the tree trunk could eventually push the wall over.
- Remove ivy from walls as soon as it emerges, as this will weaken the whole structure. Walls already overgrown with ivy may need complete reconstruction.
- Replace coping stones or their equivalent as soon as they fall off. They give the wall additional strength.
- Repair any damage to walls as soon as it happens. If left untreated, the damage will get worse and the cost of repair will increase. Where possible, to maintain the local distinctiveness, stone should be used from local quarries.
The future of Cotswold dry stone walls
There are many skilled dry stone wallers in the Cotswolds working as contractors to build, repair, or maintain traditional walls. The Dry Stone Walling Association website not only acts as a directory for these professional crafts people, but also details training events for those who want to develop their own skills.