Whether you’re enhancing your garden or managing slight slopes in your backyard, a small retaining wall offers a practical and aesthetic solution. While it may seem like a job for professionals, with the right planning and tools, you can complete this project yourself. The key is to understand each step, prepare carefully, and avoid common shortcuts that lead to structural failure over time.
“An ounce of prevention is worth a pound of cure.”
— Benjamin Franklin
Planning Your DIY Retaining Wall
Before you start digging, take time to assess the area. What’s the purpose of your wall—decorative or structural? Do you need it to handle drainage or soil retention? Mark out the shape and height of the wall, and check local building codes to ensure your design is compliant, especially if it exceeds 3 feet.
Next, choose your materials. For smaller projects, concrete blocks are often ideal—they’re affordable, easy to stack, and available in various finishes. Be sure to calculate the total number of blocks based on your wall’s length and height, factoring in a few extra for cuts or replacements.
Step-by-Step Retaining Wall DIY Process
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Excavate and level the base trench.
Dig a trench that’s wide enough to accommodate the block width and deep enough to allow for a gravel base and the first buried course of blocks. -
Add and compact the base.
Fill the trench with 4–6 inches of crushed gravel. This base must be compacted thoroughly to provide a solid, level foundation. For optimal compaction, consider using a vibratory plate tamper like the Tomahawk 6 HP Gas Plate Compactor with 3,000 lbs of Compaction Force. -
Lay the first course.
Start placing the first row of blocks on the leveled gravel. Use a rubber mallet to set them in place, checking each one for level. -
Build up the wall.
Stagger the seams as you add courses to increase strength. Some blocks may require adhesive or pins, depending on the type. -
Backfill and compact as you go.
After every course, backfill the area behind the wall with gravel to promote drainage. Compact this fill regularly. -
Cap the wall.
Finish with capstones for a polished look. Secure them using a concrete adhesive for added stability.
Final Touches and Tips
Even for a small wall, drainage is essential. Without it, water buildup can push against the wall and cause it to bulge or collapse over time. Install perforated drainage pipe behind the bottom row if your wall is more than two feet high, and ensure your backfill slopes away from the wall.
If you’re short on experience but want professional results, working methodically and using the right equipment can make all the difference.
