A dry retaining wall is set in dirt, rather than in mortar and must be sturdy enough to stand up again the pressure behind it from earth and water. The wall’s stability depends on the weight and friction of one stone on another.
Tools & Materials Checklist
- Heavy hammer or stone hammer
- Folding ruler or measuring tape
- Carpenter’s level
- String line
- Pick & shovel
How Much Stone You Need
- Determine the length and the height of your wall in feet.
Note: If the wall is no more than 3’ high, you can use an irregular or pre-split stone to make your wall an average of 8” wide. Higher walls may need a thicker construction.
- Determine the number of cubic feet of the wall by measuring the length of the wall X height of the wall X width of the wall to equal the number of cubic feet of the wall.
________ feet x ________ feet x ________ feet = _________________ cubic feet
- Select your wallstone. Since wallstone varies in thickness and density, the number of cubic feet per tone varies. Based on you stone choice, a sales person at Lang Stone can use your wall dimensions and cubic feet to determine the amount of material you need. Stone will average 145-170 lbs per cubic foot.
Constructing Your Wall
- Begin by digging a trench where the base of the wall will go, about 6” deep and 15” to 18” wide. Make sure the topsoil and vegetation is completely removed, and you are down to the sub-soil.
- Use your largest stones to cover the bottom of the trench. Use your backfill gravel, stone chips or clean dirt to stabilize and level the first course.
Note: When selecting your first course, it is a good idea to also set the broadest, flattest stone aside to use as capstones.
- After you have finished the first course, fill the remaining space with your backfill gravel or clean dirt. Be sure to firmly pack all voids to avoid settling.
- As you stack your wall, working from one end to the other, you need to do three things:
- Slope the wall back toward the higher ground. A good rule of thumb is 1 to 2” per foot. To check this, place your level on end at the base and measure back to the face of the wall.
- Stagger the vertical joints to ensure strength. Also, cut off small points to increase contact between stones.
- Continue to firmly backfill the wall. Use chips to shim as needed. each course should be stable before beginning the next.
- Occasionally, turn a long stone into the hillside or bed to act as an anchor or bond stone. This will improve the stability, especially on tall, straight walls.
- Use the stones set aside in Step 2 to finish off the wall. Use your stone hammer to fit these tightly together. Because this is the most visible portion of the wall, spending a bit more time here will give the wall a very finished look.