The art of rock walls

Sunset, Sept, 1994 by Peter O. Whiteley

Garden walls built of dry-stacked stones transcend their humble origins

Long before there were bricks or concrete, there were rocks. They were free, plentiful, and virtually indestructible. Almost anyone could pick them up, pile them together, and make a wall that would separate property, define courtyards, hold steep hillsides in place, or form planters in gardens. Of course, the professional rock workers, or stonemasons, went on to grander things, such as castles and cathedrals.

In today's world there's not much call for monumental rock-work, but the timeless skills of the stonemason are resurfacing on a smaller scale in the residential garden wall. In the hands of a skilled stonemason, a rock wall goes beyond its utilitarian role and becomes a thing of striking, permanent beauty.

The purest forms of stonework are mortarless or "dry-stacked" walls, which rely only on friction, weight, and the shape of the rocks to hold them together. The best work is as thoughtfully composed as a painting. It has graceful lines and balanced proportions, and it elegantly integrates stones of differing sizes and shapes.

The examples shown here advance the traditional craft with subtle nudges or bol strokes. They vary in scale from a foot-high garden wall made of stones most of us could lift to a taller retaining wall made of several-ton boulders that were lifted by crane. Some incorporate built-in seating, storage, fountains, and cooking areas. One forgoes function almost altogether; it implies a wall, but i really more of a sculptural assemblage of massive forms.

Unlike the rocks in fieldstone walls that march across farmlands, few of the ones in these walls retain their natural shape. Most have been sculpted and hew with the same tools that stonemasons have been using for centuries: heavy hammers and broad-pointed chisels. Shims and wedges are also employed to split boulder-size rocks. Typically, the skills and trade secrets of stonemasonry are passed on from a master stonemason to apprentices.

Granite and basalt are popular choices for walls, but a competent mason can shape many of the other types of stone commonly found at rock yards. Masons wil take rocks with irregular or rounded shapes and score, chip, or sometimes cut them to create straight edges and vertical faces. Stacked-rock retaining walls start with a broad, partially buried base and then angle, or "batter," back int the hill to resist the outward force of the earth behind. Freestanding walls ar battered on both sides.

The cost of rocks and of transporting them, combined with the time and skill required to cut and fit them, makes dry-stacked walls more expensive than those made of wood or concrete. On average, a dry-stacked wall with some cut stone costs about $35 per square foot.

However, no other type of wall can match a well-crafted rock wall for rugged good looks, the ability to blend naturally with plantings, and durability. There's something fundamentally satisfying about adding a garden wall that will outlast a wood-framed house. As master stonemason George Gonzalez says, "I like to build a wall that will last 500 years."