The Ultimate Guide to Retaining Walls: What They Are & Why They Matter

Rockwood 6" Classic

What is a Retaining Wall?

A retaining wall is more than just a stack of blocks—it's a way to enhance your home's beauty while providing essential structural support. Designed to hold back soil and prevent erosion, these walls blend strength and aesthetics to elevate your outdoor space. Whether you're managing a tricky slope or simply looking to add a sophisticated touch to your yard, a well-built retaining wall can create a lasting visual impact.

Why Are Retaining Walls Important?

Retaining walls do more than just sit there looking pretty. They play a critical role in keeping your property safe and functional:

• Erosion Control – No more watching your soil wash away every time it rains.

• Structural Stability – Keeps everything where it belongs, preventing landslides and ground movement.

• Drainage Management – The right wall design ensures water goes where it should—away from your home.

• Aesthetic Enhancement – These walls add character, function, and can even double as built-in seating or planters.

Common Types of Retaining Walls

Not all retaining walls are created equal. Depending on what you need, here are some popular types:

• Segmental Retaining Walls (SRWs) – The most common choice for residential properties, SRWs use interlocking blocks that are flexible, durable, and require no mortar. These walls are ideal for smaller landscaping projects and provide a clean, modern look while maintaining structural integrity.

• Gravity Walls – These hefty walls rely on weight to hold back soil, commonly made of stone, concrete, or brick.

• Cantilevered Walls – Engineered for extra strength, these have a reinforced base and are great for larger projects.

• Anchored Walls – Built for maximum support, these use cables or rods to stay put, making them ideal for heavy loads.

Belgard Weston Wall. Color dependent on local suppliers.

Factors to Consider When Choosing a Retaining Wall

Choosing the right retaining wall means thinking beyond just looks. Here’s what to consider:

• Soil Type – The Saint Louis and Eastern Missouri region is known for its dense, clay-heavy soil, which holds water and expands when wet. This makes proper drainage and reinforcement crucial to prevent shifting and pressure buildup behind the wall.

  
  

• Height Requirements – The general rule is that retaining walls over 3.5 feet require engineering, but this varies by municipality. In most cities around Saint Louis, a master plan is required for walls between 3 to 4 feet, while anything over 6 feet demands dedicated engineering and design. Walls taller than 3 feet often require permits, so always check local regulations before starting construction.

• Climate & Weather – In Saint Charles County and Saint Louis, freeze-thaw cycles mean drainage and reinforcement are key.

• Aesthetic Preferences – Retaining walls can be designed to match any home style, whether you prefer a modern, sleek appearance or a textured, natural look. There are a variety of color blends and finishes to complement your outdoor space. Popular brands like Unilock, Belgard, Keystone, and Rockwood offer a range of materials that allow for customization, ensuring your retaining wall enhances your landscape while providing structural support.

Basic Steps to Building a Retaining Wall

Thinking of building one yourself? Here’s a simplified step-by-step process:

• Plan & Design – Know your goal, location, and materials before you start digging.

• Excavate & Prepare Base– A solid trench ensures stability from the ground up.

• Install a Strong Base – Compact gravel or a concrete footing will set the foundation.

• Lay the First Course – This needs to be perfectly level—no shortcuts here!

• Build & Reinforce – Stack your layers properly, using reinforcements like geogrid when needed.

• Add Drainage – A perforated pipe and gravel backfill keep water pressure from building up.

• Finish & Compact – Cap it off and make sure everything is secure.

Final Thoughts

A well-built retaining wall is more than just a structural necessity—it’s a visually striking addition that transforms your outdoor space while providing essential support. Whether you're looking to create tiered garden beds, define your yard’s layout, or add a custom seating wall, the right combination of materials, textures, and colors can turn a basic structure into a statement piece that complements your home’s architecture and landscape. Whether you're looking to prevent erosion, create usable space, or enhance the overall aesthetic of your yard, the right materials and design can make a significant impact. With options ranging from sleek and modern to textured and rustic, retaining walls can seamlessly blend into your home’s style while providing long-term durability.

💡 Need expert advice on retaining wall installation? Contact United Outdoors LLC—we specialize in building high-quality retaining walls in Saint Charles County and the greater Saint Louis area! Let’s bring your outdoor vision to life!