While many materials are available, railroad ties (also called railway sleepers) offer a rustic, durable, and cost-effective option. Their substantial weight and rugged appearance make them ideal for building sturdy, long-lasting walls.
Important Safety Note: Before beginning, check your local building codes. Many municipalities have regulations regarding retaining wall height, materials, and drainage. Walls over 3-4 feet often require a permit and professional engineering. Additionally, be aware that older, creosote-treated railroad ties can leach chemicals into the soil. For garden beds containing edible plants, consider using newer, untreated ties or an alternative material.
Materials & Tools You’ll Need
* Materials:
* Railroad ties (quantity depends on wall length and height)
* Galvanized steel rebar (12-18 inches long, ½-inch diameter)
* Drainage gravel (¾-inch crushed stone)
* Landscape fabric
* Coarse sand or road base (for leveling)
* Tools:
* Tape measure, level, and string line
* Shovel, spade, and digging bar
* Sledgehammer or heavy maul
* Circular saw or chainsaw (with a carbide-tipped blade)
* Drill with a long, ¾-inch spade bit
* Safety gear: gloves, safety glasses, hearing protection, sturdy boots
Step 1:
Planning and Layout
Mark the proposed wall’s path with string and stakes. A good rule of thumb is to set the wall back 1 foot from the slope for every 2 feet in height for stability.
Measure the total length. Railroad ties are typically 8-9 feet long. Plan your layout to stagger vertical joints (like brickwork) for strength. For each vertical foot of wall height, you’ll need approximately one tie.
Step 2:
Excavate the Trench
1. Dig a level trench along your string line. The trench should be wide enough to accommodate the full width of your tie (usually 8-10 inches) and deep enough to bury the first course (layer) by at least one-third of its height. For a standard 7-inch tall tie, dig a trench about 3-4 inches deep.
2. Use a hand tamper or plate compactor to firmly compact the soil at the bottom of the trench.
Step 3:
Install the First Course
1. Lay a 1-2 inch bed of coarse sand or road base in the trench and level it.
2. Place your first railroad tie into the trench. This is the most critical step for a level wall. Use a long level and a sledgehammer to tap the tie until it is perfectly level from front to back and side to side.
To prevent shifting, drill two or three holes through the first tie down into the compacted soil beneath. Drive lengths of rebar through these holes with a sledgehammer to “pin” the base course securely to the ground.
Step 4:
Build Up Subsequent Courses
Begin the second course. Always offset the vertical seams so no joint is directly above the one below. You will need to cut some ties to length using a chainsaw or circular saw.
For each new tie you lay, secure it to the tie below. Drill two holes down through the new tie into the one beneath it. Drive rebar through these holes. For longer walls, also drill horizontally through the ends of abutting ties and connect them with a piece of rebar.
Constantly check that each tie is level and that the wall face is plumb (vertical) or has a slight backward lean (“batter”) into the hill for added stability.
Step 5:
Install Drainage (Crucial for Longevity)
Water pressure (hydrostatic pressure) is the primary cause of retaining wall failure.
1. As you build the wall, line the excavated area behind it with landscape fabric. This prevents soil from washing into the drainage gravel.
2. Fill the space behind the wall with 6-12 inches of drainage gravel as you build each course.
3. Consider installing a perforated drainage pipe at the base of the wall, surrounded by gravel, with an outlet to direct water away from the wall.
Step 6:
Backfill and Finish
1. Once the final course is pinned, fold the excess landscape fabric over the top of the gravel layer.
2. Backfill the remaining area behind the wall with native soil and topsoil.
3. You can cap the wall with a final course of ties laid flat for a finished look, or use soil and plants to soften the top edge.
Maintenance Tips
* Inspect your wall annually for signs of bulging, leaning, or rot.
* Ensure drainage outlets remain clear.
* Re-secure any loose rebar pins.
Building a railroad tie retaining wall is a physically demanding but highly rewarding DIY project. By taking your time with site preparation, ensuring proper drainage, and securely pinning each course, you can create a functional and attractive landscape feature that will serve your property for years to come.
