How to Build a Stone Retaining Wall

1. Organize the Stones

   Organize the wall stones roughly by size and shape, making different piles as needed. Do this off to the side, not on the wall location.

   Use large, flat stones for the base. Reserve smooth, undamaged stones for the capstones at the top of the wall.

2. Pare Down the Stones

   Knock off peaks and other odd formations with a brick chisel and maul, as needed, to make them fit during construction.

3. Run a Level Line

   Hammer down wood stakes and run a mason’s line between the stakes to mark the location of the front face of the base of the wall. Place a line level on the string, then pull the string taut from one end, and level the line before tying it off to the stake.

   Tip

   The trench width should be at least one-half the total wall height. For example, if the wall is 30 inches tall, the trench should be at least 15 inches wide.

4. Dig the Area

   Dig out the area, starting from the string and moving back toward the slope. Dig 12 inches into the ground to create a flat, level trench for the gravel base. Dig into the slope to create a 6- to 12-inch-wide space between the backside of the wall and the slope.

5. Add Landscape Fabric

   Cover the excavated area with strips of landscape fabric. Lay the fabric perpendicular to the front of the wall. Extend the fabric a few feet onto the upper-level ground. Overlap adjacent strips of fabric by 6 inches. Cut the strips to length with a utility knife.

6. Build the Wall Base

   Fill the trench with 5 inches of compactible gravel. Rake the gravel so it is flat and level. Tamp the gravel with a hand tamp or a rented power tamper. Add a 1-inch layer of coarse sand over the gravel. Smooth the sand with a short 2×4 board so it is flat and level.

7. Lay the First Course

   Set large, flat stones along the front edge of the trench to build the first course. Add or remove sand beneath each stone, as needed, so the tops of the stones are flush with one another. Set the 4-foot carpenter’s level across multiple stones to level the course.

8. Lay the Second Course

   Place the next course of stones on top of the first, again staggering the joints. Firmly set each stone to reduce wobble.

9. Backfill the Wall

   Fill the space between the wall and the slope with drainage gravel. Rake the gravel flat and level, and tamp it thoroughly with the hand tamp. Backfill only up to the highest course on the wall.

   Tip

   It’s better to gradually backfill rather than backfilling all at once at the end. Adding the gravel in stages ensures a dense, firm backfill.

10. Install Tie-Back Stones

    With higher courses of stones, install tie-back or deadman stones. Tie-back stones reach back into the slope to tie the wall into the earth. Place a tie-back stone every 4 feet horizontal feet.

11. Fold Back the Fabric

    Fold the landscape fabric over the drainage gravel as you near the top of the wall. You can do this before the last one or two standard courses or before the capstones (the top-most course), depending on how much soil you’d like at the top of the wall (for growing grass).

12. Place the Capstones on the Wall

    Lay the top course of stones—called capstones—to complete the top of the wall. If desired, you can glue the capstones to the course below to keep them secure. Use masonry adhesive.

13. Backfill With Soil

    Trim the landscape fabric so it is just below the top of the wall. Cover the landscape fabric and backfill behind the top of the wall with soil, as desired. To grow grass in this area, the soil layer should be at least 6 inches thick.

Stone Retaining Wall Tips

• To create a more natural or aged look, add plants in various places on the wall.
• Rougher stone will automatically have gaps large enough for packing in soil and planting.
• If you use cut stone, plan for plantable gaps when building the wall. They don’t need to be large and should not compromise the wall’s integrity.
• Flat or cut stones are much easier to work with than fieldstone and will make a sturdier wall.
• Cascading plants, such as creeping thyme, perennial yellow alyssum, and annual white alyssumcomplement stone retaining walls.
• Herbs also work well growing on or near rock walls.