While materials like concrete blocks and natural stone are popular, railroad ties offer a rustic, durable, and often more affordable alternative. Their substantial size allows for quicker construction of taller walls. However, building with railroad ties requires careful planning and execution due to their weight and potential environmental considerations.

Important Preliminary Note: Modern railroad ties are often treated with chemical preservatives like creosote, which can be toxic. For any project near gardens or areas frequented by children and pets, it is highly recommended to seek out “new, non-treated” landscape timbers or recycled composite timbers designed to mimic the look of railroad ties. Always wear gloves, long sleeves, and a dust mask when handling old railroad ties.

Planning & Safety

Before you begin, contact your local building department. Many municipalities have codes governing retaining walls over a certain height (often 3-4 feet), which may require a permit or professional engineering.

In the U.S. and Canada, always call 811 or your local utility locating service at least a few days before digging. They will mark the location of underground lines for free.

Determine the wall’s length, height, and layout. A wall taller than 3-4 feet requires advanced techniques and professional consultation. For stability, the wall should lean slightly back into the hill (a “batter” of about 1 inch for every foot of height).

Materials & Tools
Materials:
* Railroad ties or suitable landscape timbers
* Drainage gravel (¾-inch crushed stone)
* Landscape fabric (non-woven geotextile)
* Deadmen anchors (for walls over 3 feet): extra railroad ties cut to 4-5 ft lengths
* Rebar pins (12-18 inch lengths, ½-inch diameter)
* Galvanized spikes (12-inch landscape spikes) or large lag bolts

Tools:
* Shovel, spade, and digging bar
* Tape measure, level, and string line
* Circular saw or chainsaw (with a sharp blade for treated wood)
* Sledgehammer
* Drill with a long wood bit (for pre-drilling spike holes)
* Plate compactor or hand tamper
* Wheelbarrow

Step-by-Step Construction Guide

Step 1:

Excavate the Trench
Mark the front line of your wall with string and stakes. Dig a level trench along this line. The trench should be wide enough to accommodate the full width of your tie 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 4-6 inches deep. The trench base must be perfectly level and compacted.

Step 2:

Establish Drainage and Foundation
Line the back of the trench (the side against the hill) with landscape fabric, allowing excess to drape up the excavated slope. Fill the trench with 2-3 inches of drainage gravel and compact it thoroughly. This gravel bed is critical for preventing water from pooling under the ties, which causes rot and heaving.

Step 3:

Lay the First Course
Place your first railroad tie in the trench on the gravel bed. Check for level from front to back and side to side. Use gravel to shim and adjust until it is perfectly level. This course sets the stage for the entire wall, so take your time.

Step 4:

Secure the Ties and Build Up
* Drill and Spike: For each subsequent tier, stagger the vertical joints like bricks for strength. Pre-drill holes at an angle through the new tie and into the one below. Drive 12-inch galvanized spikes through the holes to pin the ties together. Use at least two spikes per tie, positioned about one foot from each end.
* Anchor with Rebar: For additional lateral stability, drive 12-18 inch rebar pins vertically through pre-drilled holes in the ties and into the ground below. Space these pins every 3-4 feet along the wall.
* Install Deadmen (For Walls Over 3 Feet): Every 6-8 feet along the wall, install a “deadman”—a tie that extends perpendicularly back into the hillside. Bury it in a trench and spike it securely to the face ties. This acts as an anchor, tying the wall into the stable soil behind it.

Step 5:

Install Backfill and Drainage
As you build each course, immediately backfill behind the wall with drainage gravel. Do not use native soil. The gravel layer should be at least 6-12 inches thick directly behind the wall. Wrap the landscape fabric over the gravel to prevent soil from clogging the drainage zone. Continue this process—lay a course, backfill with gravel, compact—until you reach the final height.

Step 6:

Cap the Wall (Optional)
A final “cap” tie can be spiked horizontally along the top of the wall for a finished look. You can use a full tie or cut one lengthwise for a smaller cap.

Step 7:

Final Grading
Once the wall is complete, backfill the remaining area behind the gravel drainage zone with native soil. Slope the final grade slightly away from the top of the wall to direct surface water runoff away from the structure.

Long-Term Maintenance
* Inspect Annually: Check for signs of bulging, leaning, or rot.
* Ensure Proper Drainage: Keep weep holes (if installed) or the gravel base clear of debris.
* Address Vegetation: Prevent tree and large shrub roots from growing into the wall structure.

Conclusion
Building a retaining wall with railroad ties is a demanding but rewarding DIY project that can transform a sloped, unusable area into a beautiful and functional landscape feature. By prioritizing a solid, level foundation, robust internal drainage, and secure mechanical fastening, you can construct a wall that is both strong and enduring. Always prioritize safety, don’t hesitate to seek help with heavy lifting, and consider professional advice for taller or complex walls. With careful work, your railroad tie retaining wall will serve your property for decades.