Drystone walls are walls made of stacked stone without the use of mortar. Four types of stones are used for drystone walls, cornerstones, base stones, mixed stones and cap stones. Cornerstones, base stones and cap stones should have at least two flat sides, bottom and top. A tie stone is a stone that is the same width as your wall. Tie stones are used to provide stability to the wall. Drystone walls are built in courses, with each course being one layer of stone. Walls two and a half feet high and lower are the easiest for homeowners to build.
Check your local building and property codes and laws to determine if drystone walls are permissible in your area. If you are building a drystone wall on your property line, make sure you have your neighbor's permission first.
Calculate the amount of stone you will need by multiplying the height of the wall by the width of the wall by the length of the wall (H x W x L). Divide the total by 15 to get the amount of stone in tons. The amount of aggregate you will need depends on the type of stone you will be using. Ask your stone supplier for help in deciding the amount of aggregate. A general rule is that you will need the same amount of aggregate as 1/2 the cubic feet of the wall.
Measure out the base dimensions (width and length) of your wall. Mark the corners with wooden stakes. Run string between stakes, or you can use limestone dust, to mark the edges of the wall. Use the string or limestone as markers to dig the base trench.
Dig a base trench 4 inches deep for walls 1.5 feet high or lower, or 8 inches deep for walls between 1.5 and 2.5 feet high. Remove stones and roots from the trench and smooth the sides and bottom.
Fill the bottom of the 4-inch deep trench with 2 inches of aggregate, or the bottom of the 8-inch deep trench with 4 inches of aggregate. Tamp the aggregate down with a commercial hand tamper, or lay a 2x4 on the aggregate and jump up and down on it several times. The aggregate provides drainage and stability for the wall. Choose cornerstones the same width as your wall. Place them, on either end of the wall, on the aggregate with the flattest side down.
Starting on one end, lay base stones in two parallel rows. Keep a small gap between the rows. The base stones should fit tightly against one another. Lay a tie stone (a stone the same width as the trench) every yard for added stability and strength. The base stones don't have to be the same height, just arrange them so they slope in towards the center of the wall (the gap). Fill the gap between the base stones with aggregate. The aggregate should be slightly deeper than the height of the base stones.
Use the mixed grade stones to form the wall. You will alternate working on either end, laying one course at a time meeting in the middle. Use stones horizontally and vertically, working across the width first, then increasing the length. Try to sets stones side by side that naturally fit or join together. Every yard or so lay a tie stone. Do not stack stones directly on top of each other, stagger the stacking so only three stones form a joint. Continue slanting the stones towards the interior of the wall. Use aggregate stones to fill in gaps.
As you finish one course, check the level. Stand the 2x4 against the wall, abut the level against the 2x4 and lay it over the top of the course. The course does not have to be perfectly level, but you don't want big dips or waves. Use aggregate stones to level out dips.
Choose capstones with two flat sides, top and bottom. Fit them on the top to complete the wall. They should be the same width as the wall.