The lowdown on dry stone walls.
Dry stone walls are as iconic as our beloved hedgerows, and are true architectural wonders. These 3D jigsaw puzzles, built without the aid of mortar or cement, can stand for centuries and provide shelter for wildlife as well as a rich habitat for mosses and lichens. So while Canal & River Trust volunteers have been busy restoring a 150-metre section of dry stone wall along the Rochdale Canal these past few weeks, we thought we'd dig out some dry stone trivia.
We have 125,000 miles of dry stone wall in Britain, some of them dating as far back as 3,500BC. The oldest known examples can be found in the village of Skara Brae on Orkney. Many of our dry stone walls are field boundaries, built in the early to mid-1800s in response to the enclosure acts.
Dry stone walls are self-supporting because of their unique construction method – a jigsaw puzzle of stones locked together under the force of their own weight. Local styles vary, but the basic rule is for the width of the base to equal the height of the wall (usually 1.4m), and the width of the top to be half that of the base.
Dry stone walls are commonly found in upland Britain, where land is higher, soil is thinner and there are more rocky outcrops. The weather is usually harsher in these areas, making it harder for trees and hedgerows to grow. In particularly windy places, you’ll find holes in the dry stone walls for the wind to pass through, making them less likely to topple over. These are called lace walls.
Just like a hedgerow, a dry stone wall offers varied habitats for wild animals, often having an exposed, wet side and a warm, dryer side. There are lots of nooks and crannies for insects and small animals to shelter in, and lichens and mosses thrive on the stones, creating rich bedding for ivy and ferns to take hold. Left neglected, though, too much vegetation growing within the walls will eventually destroy it.
Different rocks have distinct characteristics that determine how they can be split and shaped. In the north and west parts of England, rocks are older and harder than rocks in the southeast, making them less malleable to work with. Dry stone walls are usually built from local stone, helping retain their unique character, and wallers often have their own signature style, too.
The only tool a dry stone waller uses is a sharp-edged hammer, to shape the stone when necessary. A good waller seldom uses the hammer in their craft, preferring to use his or her expertise to find the perfect rock to fit the gap.
Dry stone wallers have their own unique vocabulary: a corner is a 'quoin', a layer is a 'course', and to shape the stone, in walling language, is to 'dress' it.
Words: Abigail Whyte
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