Stone Walls That Stay Built
A master waller shares how to dry-lay stone walls that hold their ground for centuries.
I began my professional training as a waller working under certified craftsmen in Great Britain, a country whose landscape is laced with stone walls that date back millenia. In New England, where I live, two-century-old walls are common. While this may come as a surprise, that’s far longer than most mortared walls last. If you learn to properly lay dry stone, you can build walls that outlast your great-grandchildren.
Mortar hurts more than it helps. While it can take years of practice to efficiently build a near-perfect wall, building a good dry stone wall is quite easy. The process starts with forgetting what you think you know about the importance of mortar. One reason for their longevity is that properly laid dry stone walls flex as the ground moves, whereas a mortared wall will crack. This flexibility often allows dry stone walls to be built directly on the native soil, while mortared work requires a concrete foundation below the frost line. And while a dry stone wall allows water to pass through harmlessly, mortared walls can trap moisture that will destroy the wall when it freezes. In a dry stone wall, the aim is to use gravity to maximize friction. Friction keeps the stones from sliding apart, and their weight increases the friction. But even the best built wall can fail if it is poorly designed.
Base the design on the site and stone. When siting, think about what can damage a wall. In northern areas, set walls back from roads and driveways so that plows won’t push snow against them. Trees growing in girth can put pressure on walls, and roots can shift or lift when a tree blows in the wind, pushing a wall up from underneath. A good practice is to stay back at least…