DIY Guide: Building a Robust Railroad Tie Retaining Wall

Retaining walls are not only functional, preventing soil erosion and managing slopes, but they can also be a beautiful addition to your landscape. Railroad ties, with their rugged charm and durability, make an excellent material for constructing sturdy and visually appealing retaining walls. This comprehensive guide will walk you through the process of building your own railroad tie retaining wall, from planning to finishing touches. Whether you’re a seasoned DIYer or a beginner looking to tackle a rewarding project, this article provides detailed instructions, helpful tips, and safety considerations to ensure a successful build.

Planning Your Railroad Tie Retaining Wall

Before you even think about picking up a shovel, careful planning is crucial for the success and longevity of your retaining wall. Here’s what you need to consider:

1. Assessing Your Site

• Slope and Height: Measure the height of the slope you need to retain. This will determine the number of railroad ties you’ll need and the wall’s overall design. A higher wall will require more structural support and potentially a different construction method.
• Soil Type: Identify the type of soil you’re working with (clay, sand, loam, etc.). Clay soils tend to be heavier and retain more water, which can create more pressure on the wall. This may require extra drainage considerations.
• Drainage: Proper drainage is essential to prevent water buildup behind the wall, which can lead to instability and premature failure. Plan for adequate drainage solutions, such as gravel backfill and weep holes.
• Existing Structures: Note the location of any existing structures, underground utilities (gas lines, water pipes, electrical cables), or property lines. Ensure you’re building a safe distance from any potential hazards and that you have all necessary permissions.
• Local Regulations: Check with your local building department about permits and regulations for retaining walls. There may be restrictions on height, proximity to property lines, and materials used. Ignoring these regulations could result in fines or even removal of your wall.

2. Designing Your Wall

• Straight vs. Curved: Decide whether you want a straight or curved wall. Curves can be more visually appealing but require more precise cutting and alignment.
• Tie Arrangement: Choose your tie arrangement. Common options include stacking ties horizontally in a running bond pattern (like brickwork) or a vertical pattern with posts buried into the ground. For most retaining walls, a horizontal arrangement is recommended.
• Wall Height and Thickness: Determine the height and thickness of your wall based on your site and retaining needs. Consider building tiered walls for very high slopes instead of a single tall wall, making your construction more stable and aesthetically pleasing. If the wall is over 4 feet high, consulting a professional might be a good idea.
• Backfill Area: Plan for the area behind the wall where you’ll place drainage gravel and the retained soil. This space will influence the wall’s footprint and stability.

3. Calculating Materials

• Railroad Ties: Determine the number of ties needed based on your wall’s length, height, and chosen tie arrangement. Allow for some extra ties in case of mistakes or unexpected cuts. Standard railroad ties are approximately 8 feet long, but they can vary.
• Gravel: Calculate the volume of gravel required for backfill and drainage. A good rule of thumb is to have at least 12 inches of gravel behind the wall. Crushed stone is typically recommended.
• Landscape Fabric: Estimate the amount of landscape fabric needed to prevent soil from migrating into the gravel drainage area.
• Rebar or Lag Screws: Decide on your method for securing the ties together – rebar pounded vertically down through the ties, or long, heavy duty lag screws. Rebar is generally preferred for vertical walls.
• Leveling Material: Plan for some sand or fine gravel to make sure the first layer of ties are level.

Tools and Materials You’ll Need

Having the right tools and materials on hand will make your project go much smoother. Here’s a comprehensive list of what you’ll need:

Tools:

• Shovel: For digging trenches, moving soil, and backfilling.
• Pickaxe: For breaking up hard soil or rocks.
• Post Hole Digger or Auger: Useful for creating holes for vertical supports or drainage.
• Level: For ensuring ties are level both horizontally and vertically. A long level is better for this job.
• Measuring Tape: For accurate measurements.
• String Line and Stakes: For creating straight lines.
• Circular Saw or Chainsaw: For cutting railroad ties (a chainsaw is much faster, but a circular saw with a carbide blade will work).
• Sledgehammer or Mallet: For driving rebar or seating ties.
• Drill with appropriate bits: For creating pilot holes for lag screws.
• Rebar Bender (optional): For bending rebar if required.
• Gloves: For protecting your hands.
• Safety Glasses: To protect your eyes.
• Hearing Protection: Essential when using power tools like a chainsaw.
• Wheelbarrow: For moving gravel, soil, and ties.
• Tamper: For compacting soil and gravel.

Materials:

• Railroad Ties: The main building material.
• Gravel or Crushed Stone: For backfill and drainage.
• Landscape Fabric: To prevent soil migration into the drainage gravel.
• Rebar (if using): For securing tiers together. Use at least 1/2″ rebar for best results.
• Lag Screws (if using): Heavy duty exterior grade lag screws for securing ties.
• Sand or Fine Gravel: For leveling.
• Wood Preservative (Optional): For prolonging the life of the ties, use after cutting.
• Concrete Mix (Optional): For creating a more stable footing, especially on unstable ground.

Step-by-Step Guide to Building Your Railroad Tie Retaining Wall

Now that you have planned your wall and gathered your materials, let’s get to the construction process. The steps below outline the construction of a typical horizontally stacked wall with rebar reinforcement. Adjust these instructions based on your wall’s specific design and requirements.

Step 1: Preparing the Base

1. Mark the Wall’s Location: Use string lines and stakes to outline the exact location of your retaining wall. This ensures a straight and consistent build.
2. Excavate the Trench: Dig a trench along the marked line, approximately 6 to 12 inches deep (depending on your wall’s height and soil conditions) and wide enough to accommodate the first layer of railroad ties. This trench provides a solid foundation for the wall. A wider trench can provide extra stability.
3. Prepare the Base: For improved drainage, fill the trench with a layer of gravel 4-6 inches deep. Compact the gravel using a tamper. Then, place a thin layer of sand or fine gravel on top of the compacted gravel. This will provide a level surface for the first course of ties. If you plan on using concrete for a more robust base, follow concrete mixing instructions carefully and make sure the base is level before placing the first layer.

Step 2: Laying the First Course of Ties

1. Level the First Ties: Place the first course of ties end-to-end in the trench. Use a level to ensure each tie is perfectly level horizontally and adjust the sand as needed. Make sure that they are sitting firmly on the base. This first course is critical for the stability of the whole wall.
2. Backfill (Partial): Backfill the outside (downslope) of the first course of ties to provide stability. Leave the backside open to allow for drainage fill in later steps.
3. Check for Alignment: Continuously check for alignment and adjust as needed. Use a string line to make sure the ties are forming a straight line.

Step 3: Stacking Subsequent Courses

1. Stagger the Joints: For a running bond pattern, stagger the joints between the ties in each subsequent layer. This adds structural integrity. Cut ties as needed to maintain this pattern.
2. Secure with Rebar (Vertical Walls) or Screws (Alternative Method): If using rebar, drill holes through the ties of the previous layer and pound rebar vertically down through multiple layers of ties using a sledgehammer. If using lag screws, pre-drill pilot holes and drive in the screws to secure each tie to the previous one. Using both rebar and lag screws provides maximum security. Rebar is recommended for walls with any significant height.
3. Check Level and Alignment: After placing each course, recheck for level and alignment. Make adjustments as needed.
4. Repeat: Repeat steps 1-3, laying more courses and ensuring correct alignment, using rebar/screws and checking level, until you reach the desired wall height.

Step 4: Installing Drainage

1. Landscape Fabric: Once the wall reaches half or desired height, lay landscape fabric behind the ties, draping it over the top edge of the ties, up against the soil. This will help keep the soil from mixing with the drainage gravel.
2. Backfill with Gravel: Fill the space behind the wall with gravel, ensuring the drainage area is at least 12 inches wide. Continue filling as you stack the courses, making sure the fabric is always separating soil from the gravel. This will help alleviate pressure on the wall from water buildup.
3. Add Weep Holes (If Needed): For long retaining walls, incorporate weep holes for water to escape by leaving small gaps every 4-8 feet on the bottom course. If this isn’t feasible you can also add a perforated drainage pipe behind the wall near the base that drains to the downslope side.
4. Compact Gravel: Compact the gravel using a tamper or plate compactor. This ensures proper drainage and prevents settling.

Step 5: Finishing Touches

1. Final Backfill: Fill the remaining space behind the wall with soil, compacting it as you go. Leave about 4 inches below the top of the wall.
2. Cap the Wall (Optional): You can cap the wall with a final row of ties or use decorative stones. This adds a finished look and can protect the top layer of ties from the elements.
3. Landscape and Finish: Finish the area around your wall by planting grass, adding mulch, or other landscaping features.
4. Apply Preservative (Optional): Apply a wood preservative to the cut ends and any areas that may be prone to rot for extra protection and longevity.

Safety Considerations

Safety should always be your top priority when tackling any DIY project. Here are some key safety considerations to keep in mind:

• Personal Protective Equipment (PPE): Always wear safety glasses, gloves, and hearing protection when using power tools or handling materials. Sturdy work boots are a must.
• Lifting Heavy Objects: Railroad ties are heavy. Lift with your legs and get help if necessary to avoid back injuries.
• Power Tool Safety: If using a circular saw or chainsaw, be sure to follow manufacturer’s guidelines. Use proper cutting techniques and keep your hands well clear of the cutting area. Make sure the area around where you are working is clear of any obstacles that may cause you to stumble or fall.
• Sharp Objects: Be cautious when working with sharp tools or rebar. Ensure you have a safe location to place tools when not in use.
• Work in Pairs: Whenever possible, work with a partner. This makes the job easier and safer, especially when lifting heavy objects. It also allows one person to spot the other, reducing the risk of accidents.
• Weather Conditions: Avoid working in extreme weather conditions (rain, snow, high winds).
• Know Your Limits: If you are unsure about any part of the process, seek assistance from a professional. Do not attempt something you are not comfortable with.

Maintenance of Your Railroad Tie Retaining Wall

With proper construction, your railroad tie retaining wall should last for many years. However, some regular maintenance will help keep it in top shape:

• Inspect Regularly: Check the wall for any signs of damage, leaning, or displacement, particularly after heavy rainfall or freezing weather.
• Address Drainage Issues: If you notice water pooling behind the wall, investigate the drainage and make necessary repairs to ensure water can escape properly.
• Clean and Repair: Remove any debris, weeds, or plants that may grow near the wall. Replace ties that show significant wear or rot. Apply wood preservative as necessary.

Conclusion

Building a railroad tie retaining wall is a challenging but rewarding project. With careful planning, attention to detail, and proper safety measures, you can construct a durable and beautiful wall that will enhance your landscape for years to come. This comprehensive guide has provided you with the necessary knowledge and steps to complete your project. Remember to tailor the process to your specific needs, take your time, and don’t hesitate to ask for help when needed. Happy building!