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HowTo Build A Retaining Wall With Alumawall

Gardening and landscaping are not just about planting flowers and shrubs anymore. With the right materials and techniques, you can transform your outdoor space into a stunning and functional area. One such innovative solution for garden beds and retaining walls is the Alumawall system. In this guide, we delve into how to build a garden bed using the Alumawall system as a retaining wall, its versatility, and all the necessary steps to ensure a successful installation.

Introduction to The Alumawall Stackable Sleeper System

The Alumawall Retaining Wall system is designed for versatility and durability. Particularly useful for those looking to enhance their outdoor space, it serves three primary purposes: supporting plants and a garden bed under your Good Neighbour® fencing, providing extra hardening, and acting as a barrier for soil. Its capability extends to being used for retaining walls up to four sleepers high. Alumawall comes in four powder-coated colours that seamlessly match the Colorbond and Good Neighbour® fencing system, ensuring aesthetic coherence in your garden or outdoor area.

Safety should always be a priority when undertaking any construction project. It is advisable to wear protective clothing and equipment, including a broad-brim hat, appropriate sunblock, gloves, and goggles for cutting and drilling processes.

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Planning Your Alumawall Retaining Wall

Marking the Area

To begin, it is important to have a clear plan for where your Alumawall retaining wall or garden bed will be located. For our demonstration, we're constructing the garden wall 500mm in front of an existing Good Neighbour® fence. Marking this accurately ensures that the installation is aligned and aesthetically pleasing.

Assembly of Panels

Assembling Alumawall is straightforward—the components snap-lock together, allowing the system to be built up to four sleepers high. This simplicity in design does not compromise on the robustness, making it a reliable choice for garden beds and retaining walls.

Post System Installation

The posts, which are a critical component of the Alumawall system, measure 1.7m in length. For straight runs, two posts are joined together, whereas for corners, they are connected at a 90° angle. These posts also come with a cap that clips in, adding a neat finish to the setup. The thickness and quality of these posts (4.3mm thick) make them suitable for heavy-duty applications, such as retaining walls that are up to four sleepers high.

Installation Process

Digging Holes

For a retaining wall that's one to two sleepers high, the holes need to be approximately 500mm deep and 200mm wide. This ensures that the structure has adequate support and stability. The process involves attaching the retaining posts—either for a continuous panel or for a corner—and then securing them with tech screws, no further than 500mm apart.

Levelling and Concrete

Before the posts are concreted, it’s essential to check that everything is level and straight. Once confirmed, the posts can be secured in place with concrete. This step is crucial for the longevity and stability of the Alumawall retaining wall or garden bed.

Final Touches

After the concrete has set, the last step is to add the finishing caps on the posts. These not only enhance the appearance of the retaining wall but also protect the inner parts of the posts.

Constructing the Garden Bed

For those looking to create a simple garden bed, it's recommended to remove the grass to prevent it from growing through the Alumawall system. In contrast, if you're building a retaining wall or planning to stack the system higher, a more complex foundation involving a stone base, egg pipe, and geofabric mat is necessary. This setup ensures proper drainage and prevents water from accumulating behind the wall.


The Alumawall Retaining Wall system is a versatile and reliable solution for creating garden beds and retaining walls. Its easy assembly, coupled with its strength and aesthetic appeal, makes it an excellent choice for gardeners and landscapers alike. Whether you're looking to enhance your outdoor area with a simple garden bed or need a more robust retaining wall solution, Alumawall provides both functionality and style. Follow this guide to ensure your project not only looks professional but also stands the test of time.

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