A dry-stack wall holds a slope with stacked stone and no mortar. Its strength comes from weight, friction, and the way each stone bridges the joint below it. Because there is no mortar to crack, a well-built dry wall tolerates the small ground movements that come with freeze-thaw — provided water can pass through it instead of building up behind it.
This note covers low garden walls. Taller walls or those holding back significant loads are an engineering question and may require a permit and a qualified designer in your municipality. Check local requirements before building.
The footing trench
A dry wall starts below grade. A levelled trench filled with compacted angular aggregate spreads the load and gives the first course a stable, draining bed. Setting the base course slightly into the slope helps the wall lean back into the bank.
Batter: leaning the wall into the bank
Batter is the backward lean of the wall face. A wall built dead vertical tends to bulge outward over time; a wall that leans back into the slope settles into itself. Builders commonly set a batter by eye with a batter frame or string, keeping the lean consistent up the face.
| Element | Purpose |
|---|---|
| Footing trench | Compacted draining base below grade |
| Face stones | Largest stones, long axis into the bank |
| Hearting | Small stones packing the wall core |
| Through stones | Long stones tying front to back |
| Backfill | Free-draining gravel behind the face |
| Coping | Top stones that lock the wall down |
Hearting and through stones
The space behind the face is packed tight with smaller stones called hearting. Loose hearting lets the face stones shift, so it is wedged firmly rather than dropped in. At intervals, long through stones reach from the face into the wall, tying the structure together so the front cannot peel away.
Drainage is structural, not optional
Water trapped behind a wall adds pressure and, when it freezes, expands. A dry-stack wall manages this two ways: the open joints in the face let water weep through, and a band of free-draining gravel behind the wall keeps saturated soil away from the stone. Where the retained soil is heavy, a perforated drain at the base carries water to a safe outfall.
A build sequence
- Excavate and level the footing trench; compact a granular base.
- Lay the largest face stones first, long axis pointing into the bank.
- Pack hearting tightly behind each course.
- Place through stones at intervals as the wall rises.
- Backfill with free-draining gravel as you go.
- Set heavy coping stones to lock the top course.
Choosing stone for a dry wall
Flat-bedded stone stacks more readily than rounded fieldstone, though both are used. Local quarried stone often splits along predictable beds, which speeds building. Ask suppliers for wall stone or building stone rather than decorative cobbles, and keep a range of sizes on hand for face, hearting, and coping.
Continue reading
The gravel band behind the wall connects directly to site grading — see managing drainage around hardscaping. For the path that often runs along the base of a wall, see laying a flagstone path.