DIY Series: How to Build a Stone Retaining Wall

A properly built, long-lasting retaining wall could be the answer to most homeowners’ problems with slopes, limited space, and a lackluster landscape design. And it’s a relatively easy DIY project, as long as you’re willing to rent some equipment and bury your hands in the dirt for a weekend.

If so, this guide is for you. Our contractors in Stamford, CT, are here to teach you how to build a stone retaining wall with no mortar or cement needed. All you have to do is master some basic techniques, roll up your sleeves, and haul some rocks. Let’s dive in.

The Dry-Stack Method: What Is It and Why Use It

Yes, it’s true, you don’t always need cement for a DIY natural stone retaining wall. The dry-stack method (famously called “mortarless”) is a great alternative to the traditional concrete footing, in which stones are piled so they lock together under their own weight. And the best part is that you don’t have to worry about the hydrostatic pressure that topples many mortared walls, since the gaps between stones let the water seep through.

Moreover, natural stone materials are known for surviving freeze-thaw cycles far better than rigid masonry, making these structures practical in the icy winters of Connecticut or the warm Southwest. Plus, many professional masons favor dry-stack for its eco-friendly use of locally quarried fieldstone. And as a home improvement project, it really pays off: when built on a deep, well-drained gravel base, a dry-stack wall as low as 3 feet can last generations with minimal maintenance.

Tools and Materials You’ll Need

• Stones: Flat-faced fieldstone, ledgerock, or quarried building stone (learn how to pick the best type here). Aim for a mix of sizes, 6–12 inches deep.
• Drainage gravel: ¾-inch crushed stone for the base and backfill.
• Landscape fabric: Non-woven geotextile to keep soil out of the gravel.
• Deadman stones: Long tie-back stones (24–36 inches) to anchor the wall (for walls bigger than 3 ft).
• Tools: Mason’s line, stakes, line level, tape measure, shovel, digging bar, mattock, wheelbarrow, tamper or plate compactor, brick hammer or mini-sledge, brick chisel, safety glasses, work gloves.
• Drain tile (perforated PVC) if your site is exceptionally wet.

Step-by-Step Guide on Building a Stone Retaining Wall

1. Sort the Stones

The first step in building a retaining wall with stones is to organize. Lay your stones out on pallets or tarps by size and thickness. Group the largest, flattest pieces for the first course and capstones; the medium pieces for the middle; and the odd shapes for chinking gaps. We know sorting each individual stone might seem tedious at first, but this step speeds installation and results in tighter joints.

2. Place a Level Line

Drive wood stakes at each end of the wall’s footprint (ideally following the contour line of your slope) and stretch a mason’s line between them. Use a line level to make sure it’s dead horizontal. Mark the wall’s face on the ground with line paint to keep the excavation accurate.

3. Excavate the Area

For a level trench, you must dig it the entire length of the wall, at least twice as wide as your widest stone, and deep enough to reach undisturbed subsoil. This is typically 6 inches below grade for the base, plus half the visible wall height. For a 2-foot-tall wall, that’s roughly 18 inches of total trench depth in Stamford’s loamy soils. Once you finish digging, tamp or compact the area until it’s firm.

4. Add Landscape Fabric

Line the back of the trench and the excavated hillside with non-woven landscape fabric. Don’t worry about it draping into the trench, because you’ll fold it over the gravel backfill later. Think of this fabric like a coffee filter: water flows through, but soil stays put, preventing muddy blowouts after heavy rain.

5. Create the Wall Base

A solid base is the #1 factor for a durable retaining wall. Therefore, this step determines the success of your project. Take as much time as you need to give it the attention and detail it deserves. First, you’re going to fill the trench with 4–6 inches of ¾-inch crushed gravel, level it, and compact it. Then, slope the base ⅛ inch per foot toward the wall’s front to encourage water to move downward instead of building up behind the structure.

6. Lay the First Course

For this step, we strongly recommend using flat stones. Set the first stones on the gravel, adjusting them as needed until you’re sure they won’t shift around. Keep in mind that the rest of the stones should sit ½ inch behind the ones below them (creating a subtle backward lean called “batter”). This forms a rock wall that wedges into the hill, preventing it from tipping forward. Finally, check each stone front to back and side to side with a 2-foot level; shim with chips of stone, not soil.

7. Lay the Second Course

Now that you have your foundation, you’ll need to stagger the vertical joints like bricks. A stone should bridge the joint between two stones below it (“two-over-one rule”). As you stack, keep batter consistent by measuring the setback from a plumb line every 2–3 courses.

8. Backfill the Wall

After every 8–12 inches of height, shovel 4–6 inches of gravel backfill behind the stones and tamp it. This drainage layer reduces weight against the wall and channels runoff to daylight. We suggest you avoid fine soil as backfill because it retains water and exerts pressure.

9. Install Deadman Stones

For walls taller than 24–30 inches, slide a long, flat rock perpendicular to the face every 4–6 feet along a course; its tail reaches back into the slope. The soil and gravel atop these “deadmen” act like anchor weights, tying the wall body to the hillside for extra shear resistance.

10. Complete the Wall

Continue stacking courses, alternating stone sizes for tight interlock and batter. Save your most attractive, uniform stones for the cap. You can glue the top stones to the ones below with masonry adhesive to lock everything together. A ¼-inch pitch from back to front sheds water off the wall top.

11. Backfill with Soil

Fold excess landscape fabric over the top of the gravel, then add native soil up to grade. Top with mulch or sod. The finished wall should rise 6–8 inches above backfill grade to show off the stone and keep soil from spilling over.

Tips for Your DIY Retaining Wall

• Mind local codes: Many U.S. municipalities cap unengineered retaining walls at 3–4 ft; above that, you’ll need a permit and possibly engineered drawings.
• Use the right rock: Dense, angular stones (granite, quartzite, bluestone) lock better than rounded river rock.
• Keep joints tight: The smaller the gap, the less room for erosion. Tap stones with a mason’s hammer to seat them firmly.
• Proper drainage is non-negotiable: If you notice water pooling behind the wall, retrofit a perforated drainpipe at the base and vent it downhill to daylight.
• Seasonal settling: A new wall may settle ¼ inch during its first winter. Check the level each spring and wedge smaller stones where needed.
• Safety first: Stones are heavy, so use proper lifting techniques and consider renting a small skid steer for walls over 3 feet long. Heavy gloves protect fingertips from pinches and sharp edges.