How to Build a Dry-Stack Stone Retaining Wall

Gravity is the primary force acting on any slope, and stone is the best tool for the job of taming it. A dry-stack wall relies on the weight of the stone and precise positioning rather than mortar, allowing the wall to drain naturally and shift slightly with the frost cycle without cracking. Building a wall that stands for decades requires a solid foundation and a keen eye for geometry. Done well, your wall will serve as both a structural barrier against erosion and a permanent aesthetic anchor for your landscape. You are essentially building a puzzle where every piece contributes to the stability of the entire structure.

1. Dig Deep, Build Right. Dig a trench along the base of the slope about 12 inches wide and 8 inches deep. Ensure the bottom of the trench is firm, compact soil, as this will prevent the wall from sinking over time.
2. Compact Your Base Layer. Fill the trench with 4 to 6 inches of compacted crushed stone. Level this base carefully, as any inconsistency here will telegraph through to the top of your wall.
3. Lock the Foundation. Place your largest, flattest stones into the gravel base, burying the bottom third of each stone. Ensure these base stones are perfectly level both front-to-back and side-to-side.
4. Stagger Joints for Strength. Continue stacking stones, ensuring that every vertical joint is bridged by the stone above it. Never let two joints align vertically, as this creates a weak point where the wall can split.
5. Prevent Water Damage. After every two layers, fill the space between the back of the wall and the hillside with clean, crushed stone. This layer of stone prevents water buildup, which is the primary cause of wall failure.
6. Crown Your Wall. Finish the top of the wall with large, uniform flat stones to lock the structure in place. These capstones should be heavy enough that they cannot be easily shifted.