How to Build a Dry-Set Stone Wall
A mortarless, or dry-set, stone wall imparts an old-style character to the landscape. A well-built dry-set wall will last for years. The first settlers in America built walls this way, and many of those walls are still standing today.
Besides not requiring mortar, a dry-set wall doesn't need a footing. It will flex as the earth moves due to freezing and thawing, but it won't fall down. For this kind of durability, however, you must select stones with as much surface contact between them as possible.
Where the contour of the stones form spaces that could cause the stone to move, fill in with small pieces of stone. You'll also need bondstones — long, flat stones that are long enough to span the front and rear wythes of the wall, tying them together. Taper the sides of the wall inward from bottom to top about 1 inch for every 2 feet of height. You might have to cut the upper course of bondstones to length.
What You Need
- Round-nose shovel
- Mason's line
- Circular saw
- Mason's hammer
- Stone chisel
- Cordless drill
- 1x2s (for batter gauge)
- 1-1/2-inch screws
Building a Dry-Set Retaining Wall
A dry-set stone retaining wall goes up using the same techniques as a freestanding wall but requires thicker stones throughout. Deadmen (long bondstones) are set into the slope to tie in the structure, and a drainage system is required to prevent water from building up behind the wall and exerting pressure on it. When you cut away the slope for the wall, allow enough room to dig the trench so the wall's rear edge falls 15 to 19 inches from the base of the excavation. Build the wall two courses thick, backfilling it with gravel as you go and setting bondstones every three or four courses. Be sure to batter the wall so the weight of the soil won't push it out.
Step 1: Sort Stones
Sort the stones into size groups. Use the largest, flattest stones for the base, smaller stones for the succeeding courses, and smaller chunks for filling in. For the wall footing, lay out and excavate a trench 8 inches deep and 6 inches wider than the wall on each side and at each end.
Step 2: Add Gravel and Lay First Course
Shovel about 4 inches of gravel into the trench; level and tamp it. Set bondstones on both ends of the trench. Using stones of different lengths, lay the front wythe (face) of the first course. Place a bondstone every 4 to 6 feet. Set the thinner edge of the stones in the center of the trench.
Step 3: Fill Wall and Continue
Lay the back wythe of the wall and fill the space between the two wythes with small stones or rubble. Continue laying the courses, choosing stones with the same thickness but a variety of lengths in each course. Offset the joints of the previous course. Cut stones if needed.
Step 4: Check Batter
Check the batter — the taper from bottom to top — with a batter gauge as you work. Reposition stones if necessary, and vary the width of the stones on alternate courses. Every third course, set bondstones at 3-foot intervals.
Step 5: Lay Top Course
Choose the flattest, broadest stones for the top course. Mortar the capstones in place if you like. Tip the stones in the top course slightly toward the face of the wall to improve drainage by inserting small flat stones under them.