Landscapes, Streetscapes, Parks & Garden Fixtures

The Other Dry Wall

Constructing traditional mortarless walls requires an eye for regional styles and a feel for the material.

Click here for a list of suppliers of benches

Click here for a list of suppliers of fences and gates

Click here for a list of suppliers of landscape stone

Click here for a list of suppliers of retaining walls

 


A dry stone wall may be used for a variety of applications; historically, they were used to separate crops and livestock.

By James A. Asbur


Dry stone walls are labeled dry because they are built without cement or mortar. They are very strong and can last hundreds of years. Historically, dry-stone walls were used to separate crops and livestock, but today they can be built for a variety of uses: as purely aesthetic elements, fencing or other applications. Just like other architectural elements, they vary in style from region to region, ranging from thin-slab structures to round stones set in a single face.

The first step in designing a dry stone wall in a landscaping application is to decide its purpose. It may direct guests to the front door, block off a backyard or define formal or informal spaces. Next, the surrounding area should be considered; landscape and home features will look better when reflected in the new stonework on the property. In addition, the planned wall should complement any existing stonework. For example, a rustic, random-pattern granite porch would be ill fitted with the symmetrical lines of flat Pennsylvania flagstone. Sizing is also important. Walls should be kept in proportion with the size of the connected buildings. Large homes can support larger walls.

To begin construction, sod from the wall bed must be cut aside, removing all topsoil to use a natural drain bed of approximately 6 to 8 ins. If drainage is poor, clean crushed gravel may be added to the base of the wall. Once the sub-base is in place, string lines can be set.

Rather than lifting them, thicker, heavier stones should be used to build a sturdy wall base. It is advisable to set a base for only that which can be accomplished in a few days, instead of laying the entire area of the wall. By completing just one section of wall a day, the waller will not need to walk back and forth carrying stones, which should ideally be picked up once and then set.


As the stone wall is built up, the batterring strings are raised to a few inches above the height of the stone course being stacked.

All stone should be set with the longest face of the stone running into the wall. The stone should cover one-third of the width of the wall to ensure stability. Base stones may vary in thickness; a level grade can be established by digging down into the sub-base to accommodate thicker stones, which must be set in place tightly. This can be accomplished by packing each stone from the back with clean small stones, leaving no space under any stone once it is set in place.

When all base stones are set, the base interior should be packed, or hearted, with smaller stones of various sizes. Gaps between the base stones should be filled tightly. Avoid crushed gravel for this purpose because it tends to be rounder and offers less friction. Never pack from the outside, and never set on an outward slant. Some would even argue that a slight inward slant is desirable, to help keep a wall pulled into its center. Gravity acts on the slight slant of the stones, pulling them inward and holding them in place despite frost heave and the elements.

Once the base is set, the next step is to test it. A waller should walk over the stones, stepping on each one, to make sure the stone does not move.


At about 3 ft., through stones are put in place. These stones are the same width as the wall and provide stability.

After the base is tested, the batter frames can be set up. The battering of a wall refers to the gradual narrowing of the wall as it grows taller. Most walls are built so that they will become 2 ins. narrower for every foot taller. Set up a wooden batter frame at each side of the construction to ensure proper batter. Keep the strings a few inches above the height of the stone being stacked. This narrowing of the wall is important in resisting the elements, as the upper half of the wall is always sitting on a wider base. The first course of wall should be set on top of the base stones, with the longest length of the stone running into the wall. After placing a stone, pack the next one to keep them tight. Each wall stone should be packed with smaller stones.

At this point, the strings may be raised a few inches, and the next course of wall stone can be added. Most wallers prefer to work a small area, alternating sides so as not to over-stone one side of the structure. The structure should be brought up one course at a time.

The rule for setting stone is one over two and two over one. A wall stone must break the joint or meet the two stones below it. This is called covering the joints. If several stones meet in a vertical line, it is referred to as a running joint, which is a weak point that will create problems in the future. Alternating the length of the stones in the same course will give the wall strength.

As the courses of stone are added, the strings are raised on the batter frame. Stones should never touch the strings but should be kept close and in line. A wall should not be taller than the string lines at any time during construction. The process of building level stages of stone, breaking joints, packing and checking and re-checking for spaces between stones goes on until the wall reaches 3 ft.


When the final height is reached, the structure is ready for capping.

At that level, through stones are placed into the wall. Through stones extend from one face of the wall to the other and provide stability. Place these stones on 3-ft. centers, always breaking joints. Some can extend past the string line to show their placement, while others should be flush with the strings, depending on the style of the wall. Walling around the through stones can then continue.

The most common answer for removing unwanted bumps or changing stone shape is a quick hit with a brick or stone hammer; however, some stones are almost unchangeable. For example, New England has many oddly shaped stones that are too hard to cut in a timely manner. To use them without modification is the best way to build a wall. For this reason, it is essential that a waller has a feeling for stone. He or she should be able to pick up a stone only once, having in the mind’s eye some idea of what stone will come next and an understanding of how it can work in the next hole. This is the only way to keep up momentum.

When the final height is reached, the structure is ready for capping. Caps, which should reach from one side of the wall to the other, hold the wall together in the same way as the through stones and are the first protection against animals and weather. In some cases, additional height is gained with capstones that stand in a soldier course on top of the caps. When tightly placed, capstones are almost impossible to jar apart. If the final width of the wall is known from the beginning, stones of the correct length can be put aside for this purpose when found.

Stone lasts a long time and is almost completely maintenance free. Building the wall properly will ensure its long life. To find contractors who build walls of stone professionally, contact the Dry Stone Walling Association of Great Britain or the Dry Stone Conservancy, located in Lexington, KY. Both groups operate certification programs that instruct in the art of dry stone wall construction and help link contractors to clients.


James A. Asbury founded Mountaineer Stone in 1998.

Click here for a list of suppliers of benches

Click here for a list of suppliers of fences and gates

Click here for a list of suppliers of landscape stone

Click here for a list of suppliers of retaining walls