Securing railroad ties comes down to pinning them to the ground and to each other using rebar, galvanized spikes, or a combination of both. The method you choose depends on whether you’re building a single-course border, a multi-tier retaining wall, or stacking ties for raised beds. In every case, the key is pre-drilling holes and driving fasteners deep enough to lock the ties in place so they can’t shift, slide, or bow outward over time.
Pinning Ties to the Ground With Rebar
Rebar is the most common fastener for securing railroad ties, especially for retaining walls. The ridges along the surface of rebar grip both the wood and the surrounding soil, creating a hold that smooth metal can’t match. For most projects, half-inch rebar works well. Drill a 3/8-inch hole through the tie rather than a 1/2-inch hole. The slightly undersized hole forces a tight fit when you hammer the rebar through, which prevents the tie from rocking or shifting on the pin.
Cut your rebar pins to 24 inches for single-layer installations. That length lets you drive through one tie (roughly 7 inches thick) and still sink about 6 inches into the ground beneath it, with enough pin left inside the timber to hold firmly. For an 8-foot tie, place one pin roughly every 2 feet, giving you four pins per tie. That spacing keeps the entire length anchored evenly.
Cutting one end of each rebar pin at an angle makes a huge difference. The pointed tip drives through compacted soil and wood far more easily than a blunt end. Start the pin with a 5-pound hand sledge to set it straight, then switch to a 10-pound sledge hammer to finish driving it home. When the pin is almost flush, leave about 4 to 5 inches sticking up above the tie and bend that exposed end over with the sledge. Bending the top locks the tie down so it physically cannot slide off the pin.
Galvanized Spikes for Lighter Projects
For garden borders, edging, or anywhere you’re laying ties flat on the ground without stacking, hot-galvanized landscape spikes are a simpler option. These are typically 12 inches long with a 3/8-inch diameter and a smooth shank. They drive faster than rebar and resist rust, but they don’t grip the surrounding soil as aggressively. If you’re building anything taller than one course, rebar is the better choice. Spikes work best when the tie just needs to stay put against foot traffic, mower vibration, or light soil pressure.
Stacking and Securing Multiple Courses
When you’re building a retaining wall or stacking ties two or more courses high, every layer needs to be pinned to the one below it. The process repeats for each course: set the new tie on top of the previous one, drill through the upper tie and as deep into the lower tie as you can, then drive in the rebar pin. Use 24-inch rebar for two-course connections so the pin passes through both ties. For walls three courses or higher, use 18-inch pins between the upper courses, since you’re connecting tie to tie rather than tie to ground.
Stagger your joints like brickwork. If your bottom course has a seam at the 4-foot mark, make sure the tie above it spans continuously over that seam. This prevents the wall from hinging at a weak point. Place rebar pins on both sides of every joint, within 6 inches of the end of each tie.
Drilling Through Railroad Ties
Railroad ties are dense hardwood, often oak or similar species, and they’re saturated with preservative that makes them even tougher to drill. A standard wood bit will burn out quickly. Carbide-tipped auger bits designed specifically for tie boring are available in 9/16-inch, 11/16-inch, and 3/4-inch diameters. For rebar pinning, a 3/8-inch or 1/2-inch carbide bit handles most jobs. Match your bit diameter to your rebar size, keeping the hole the same size or just barely larger than the pin.
You’ll need a heavy-duty drill with high torque. A standard cordless drill may struggle, especially on ties that have aged and hardened. A corded half-inch drill or a right-angle drill gives you the power and leverage to bore through 7 inches of dense timber without stalling. Drill slowly and pull the bit out periodically to clear sawdust from the hole.
Base Preparation and Drainage
How you prepare the ground under your first course matters as much as the fasteners you use. Dig a shallow trench the width of the tie, deep enough that the bottom tie sits about half its thickness below the surrounding grade. This prevents the base from sliding forward under soil pressure. Level the trench with 2 to 4 inches of compacted gravel. Gravel gives you a stable, well-drained surface to build on and lets water escape instead of pooling behind the wall.
For retaining walls, fill the space behind each course with gravel as you stack. After placing each tie, shovel gravel behind it and tamp it down firmly before adding the next course. This gravel backfill serves two purposes: it drains water away from the ties (extending their lifespan) and it reduces the hydrostatic pressure that pushes against the wall during heavy rain. Without drainage, water-saturated soil can exert enormous force on a tie wall, eventually pushing it outward regardless of how well it’s pinned.
Deadman Anchors for Taller Walls
Any retaining wall over two feet tall needs additional reinforcement beyond vertical rebar pins. A “deadman” anchor is a tie that runs perpendicular to the wall face, extending back into the hillside. Think of it as a horizontal arm reaching into the retained soil. The weight of the earth sitting on top of the deadman holds the wall in place.
Install deadman anchors every 4 to 6 feet along the wall’s length, typically starting at the second or third course. The anchor tie should extend at least 3 to 4 feet back into the slope. Pin it to the face tie with rebar just as you would any other course connection. At the back end, some builders attach a short cross-piece (forming a T shape) to increase the area of soil bearing down on the anchor. For walls over 4 feet tall, engineering advice from a local professional is worth the cost, since soil type, slope angle, and water conditions all affect how much reinforcement you need.
Safety Considerations for Creosote-Treated Ties
Most salvaged railroad ties are treated with creosote, a tar-based preservative that gives them their dark color and distinctive smell. The EPA has determined that handling creosote-treated wood after it has been treated does not pose health risks of concern to the general public or to workers. Reuse of these ties in residential landscaping is legal and not regulated under federal pesticide laws.
There are a few practical precautions worth taking. Wear gloves when handling ties, since creosote can irritate skin on prolonged contact. Never burn creosote-treated wood, as the smoke and ash release toxic chemicals. And avoid using railroad ties to build raised beds for vegetable gardens or anywhere edible plants will grow, since creosote compounds can leach into surrounding soil over time. For purely structural or decorative landscaping, they remain a durable, affordable option.