Large rock retaining walls remain the most effective solution in erosion control and, at the same time, beautifying outdoor spaces. They provide protection against unstable terrain and land degradation.
If you are a homeowner looking to improve your outdoor space or you want to stabilize a slope, large rock retaining walls offer a natural and durable option.
In this blog post, Douglas Fir Landscaping will help you understand what a retaining wall is, how it works, its benefits, and how to build one. Let’s start.
What is a Large Rock Retaining Wall?
Built using natural or engineered stones, a large rock retaining wall is a type of structure that serves to hold back soil and prevent erosion in landscapes. It is landscape structure and design that is commonly used in gardens, slopes, driveways, and large-scale construction projects to provide structural support.
Rock retaining walls are popular in improving the aesthetic appeal of outdoor spaces as well.
Four Types of Rock Retaining Walls
There are four types of rock retaining walls. These are: dry-racke rock walls, mortared rock walls, gabion rock walls, boulder retaining walls.
Here how each type differs:
Dry-Stacked Rock Walls (No Mortar)
Dry-stacked rock walls are built by stacking stones without mortar. The structure relies on gravity and tight placement for stability, and through gaps between rocks, the wall allows natural drainage which makes it ideal for areas with water runoff.
Dry-stacked rustic look and can last for decades but require precise stone placement for durability.
Mortared Rock Walls
Rock walls built with mortared rocks are better suited for taller or more structural applications. It uses cement-based adhesive to bond the stones together, which provides extra strength and rigidity, in return.
But while they offer a polished and durable look, they require more time and materials for construction. It requires drainage solutions as well to prevent water buildup.
Gabion Rock Walls
It is a type of rock retaining well that uses wire mesh cages filled with rocks. This offers high durability and flexibility, and is commonly used for erosion control along riverbanks, highways, and steep slopes due to their excellent drainage properties.
Over time, vegetation can grow between the rocks, enhancing their stability and blending them into the natural landscape.
Boulder Retaining Walls
Boulder retaining walls use large, heavy stones to create a strong and long-lasting structure. They are ideal for stabilizing steep slopes and supporting heavy soil loads but often require heavy machinery for installation. These walls provide a rugged, natural look and require minimal maintenance over time.
Materials Used in Rock Retaining Walls
A rock retaining wall is built with either one, or a combination of two to three types of stones. Here are the common stone materials used in building rock retaining walls.
- Granite: Extremely strong and weather-resistant.
- Limestone: Popular for its natural look and workability.
- Sandstone: Aesthetic appeal but may erode over time.
- Fieldstone: Uneven, naturally shaped stones for a rustic look.
- Concrete Blocks: Can mimic the look of real stone but are more uniform.
The Benefits of Large Rock Retaining Walls
1. Erosion Control
Large rock retaining walls prevent land degradation due to rainfall, wind, or human activity. It is ideal for properties on sloped or unstable land too.
By strategically placing boulders and stones, these walls create a sturdy barrier that holds soil in place and reduces runoff.
2. Aesthetic Appeal
Beyond their functional advantages, large rock retaining walls add a rustic and natural charm to any landscape. The variety of stone sizes, shapes, and colors allows for customization to complement the surrounding environment.
These walls blend seamlessly with gardens, driveways, and outdoor living areas, enhancing property value and curb appeal.
3. Durability and Low Maintenance
Unlike wooden or concrete retaining walls, large rock structures require minimal maintenance and have an extended lifespan. Rocks are naturally resistant to weathering and structural damage, making them a long-term investment that can withstand the test of time without frequent repairs.
4. Eco-Friendly Solution
Large rock retaining walls utilize natural materials, reducing the need for synthetic building materials. This environmentally friendly approach helps maintain ecological balance and promotes sustainable landscaping practices. Additionally, these walls allow water to pass through gaps, preventing excessive runoff and promoting better groundwater absorption.
Applications of Large Rock Retaining Walls
Residential Landscaping
Large rock retaining walls are a popular landscape design to define outdoor spaces. It creates terraces on sloped yards, and adds unique focal points to their outdoor designs.
These walls can be designed to complement flower beds, patios, and pathways.
Commercial and Infrastructure Projects
Businesses, parks, and municipalities often rely on large rock retaining walls for public spaces, roadsides, and large-scale landscaping projects. Their stability makes them ideal for managing steep embankments and preventing landslides.
Agricultural and Rural Use
Farms and rural properties can also benefit from adding rock retaining walls into their outdoor spaces. Doing so can help manage erosion in fields, protect crops from soil displacement, as well establish stable livestock enclosures.
How to Build a Large Rock Retaining Wall
Step 1: Site Preparation
Begin by evaluating the area where the rock retaining wall is planned to be built. Remove debris, level the ground, and establish a solid foundation.
Proper drainage planning is also crucial to prevent water buildup behind the wall.
Step 2: Selecting the Right Rocks
Choose quality, durable stone materials that fit well together. Common options include limestone, granite, and sandstone. Also, large and irregularly shaped rocks are typically used to ensure a secure and interlocking design.
Step 3: Layering and Stacking
Start with the largest rocks at the base, ensuring they are firmly set in place. Continue stacking the rocks, filling gaps with smaller stones for added stability. Slightly sloping the wall backward (a technique called “battering”) enhances structural integrity.
Step 4: Securing and Finishing
Once the wall reaches the desired height, reinforce it with additional compacted soil or gravel behind the structure. This step improves drainage and prevents pressure buildup. Adding plants or ground cover around the wall can further enhance its stability and aesthetic appeal.
Protect Your Home from Erosion
A rock retaining wall offers a long-lasting and durable way to protect your home from erosion. Not to mention they can also be used to enhance outdoor spaces through professional landscaping.
If you are thinking of installing a large retaining wall in your backyard, it is wise to reach out to a professional landscaping service.
Douglas Fir Landscaping offers exceptional landscaping design services, including rock retaining wall installation and design. We use quality materials, built by a team of professional landscapers.
Contact us today at (720) 806-6808 or send us a message.