How to Build a Retaining Wall

Building a Retaining Wall: Essential Tips and Considerations for a Safe and Functional Garden
Are you struggling with soil erosion or unstable ground in your backyard or garden? A well-constructed retaining wall can be the perfect solution, offering both functional support and aesthetic appeal. Whether you're looking to prevent soil runoff, create level planting areas, or enhance your landscape design, understanding the process of building a retaining wall is crucial. Here's a comprehensive guide to help you plan, build, and decide whether to DIY or hire a professional.

Key Tips Before You Start

Choose the Right Materials
Selecting appropriate materials is foundational. Common options include wood, stone, or concrete blocks. Consider your garden’s style and durability needs:
- Wood: Cost-effective and easy to work with but less durable over time.
- Stone: Natural appearance, long-lasting, but may require more effort to install.
- Concrete Blocks: Versatile and interlocking options available; some require masonry cement, others are interlocking.
Incorporate Proper Drainage
Water buildup behind the wall can cause pressure and potential failure. To prevent this:
- Fill the back of the wall with gravel or sand to facilitate drainage.
- Install a drainage pipe if you expect heavy or frequent rainfall, ensuring water can escape efficiently.
Build on Dry Soil
Construct your wall only after the soil has dried completely. Wet soil can expand and lead to inaccurate measurements, compromising the wall’s stability.

Essential Materials and Tools

To ensure a smooth building process, gather the following:
- Blocks: Concrete, stone, or wood, measured accurately to match your planned dimensions.
- Adhesive: Masonry cement or interlocking mechanisms, depending on your chosen material.
- Shovel: For digging the trench and leveling the foundation.
- Tape Measure: To mark precise measurements for length, height, and curves.
- Gravel: For the base and drainage backfill.
- Circular Saw with Masonry Blade: To cut blocks as needed.
- Capstone Blocks: To add a finished look at the top of your wall.
- Drainpipe: To route water away from the wall and prevent pressure buildup.
Depending on your project’s complexity, additional tools or materials may be necessary. When in doubt, consulting a professional can save time and ensure safety.

Estimating Costs

The total cost of building a retaining wall varies based on several factors:
- Materials: High-end materials like stacked stone can cost up to $75 per foot.
- Size and Dimensions: Larger walls require more materials and labor.
- Construction Method: Techniques like anchoring, cantilevering, or rammed earth influence costs.
- Drainage Components: Drainpipes and gravel add to expenses, potentially up to $75 per linear foot.
DIY vs. Hiring a Contractor
- DIY: Expect costs between $25 and $75 per square foot for materials. This approach is suitable for smaller, straightforward projects.
- Professional Installation: Contractors charge approximately $50 to $75 per hour, with larger or more complex walls benefiting from expert craftsmanship and engineering.

Planning and Measuring

Accurate measurements are vital. Use a tape measure to determine the length and height of your planned wall. Mark the corners with stakes and tie them with mason’s string to visualize the layout, especially if your wall includes curves or bends. Precise planning ensures you purchase enough materials and dig a proper foundation, preventing costly mistakes.

DIY or Hire a Professional? Making the Right Choice

Deciding whether to build your retaining wall yourself or hire a contractor depends on several factors:
- Experience: If you’ve completed other DIY exterior projects, you might handle a smaller wall. For taller or more complex structures (over four feet), professional expertise is recommended.
- Permits and Regulations: Some areas require permits for retaining walls, especially those affecting drainage. Contractors often manage this process more efficiently.
- Project Scale: Larger or intricate walls demand more time, effort, and skill—outsourcing can save you stress and ensure safety.
If you’re unsure about your skills or the project’s scope, consulting a local REALTOR® or landscape professional can provide valuable recommendations and references.

Building a retaining wall is a rewarding project that enhances your landscape’s stability and beauty. With careful planning, the right materials, and consideration of your skill level, you can create a durable, attractive feature that stands the test of time. Whether you choose to DIY or hire a pro, understanding these essential tips will help you achieve a successful result.