Building a retaining wall might seem like a daunting task reserved for seasoned DIY enthusiasts or professional landscapers. However, with the right guidance, it’s a project that many homeowners can tackle to transform their outdoor spaces. Whether you’re looking to prevent soil erosion, create terraced levels on a sloping yard, or simply add aesthetic appeal, this step-by-step guide is designed to take you through the process of building retaining walls safely and easily.
We’ll break down the complexities of planning, materials selection, construction techniques, and compliance with local regulations into digestible steps, ensuring your project not only enhances your property but also stands the test of time. Get ready to roll up your sleeves and bring your outdoor vision to life with confidence and ease!
Planning Your Retaining Wall Design
When building a retaining wall, planning is everything. Before you begin the project, take time to consider your goals and the design that best suits those goals. For example, if you want to prevent soil erosion, your retaining wall will be different than if you’re using it to create raised garden beds. Consider the size of your property as well. If your land is flat, a small retaining wall might not be essential compared to a steep slope.
READ: How Much Does A Concrete Sleeper Retaining Wall Cost?
Another element of planning is understanding the materials needed. Do some research on what materials are best for your specific project, for example, concrete sleepers or natural stone. Ensure they can withstand exposure to weather such as rainwater runoff from roofs, frosts or heatwaves.
While concrete sleepers may be ideal for some projects due to low costs and ease of installation, other homeowners may prefer more natural options such as large boulders or stones native to their region. It’s important to remember that every option has its benefits and drawbacks.
With the design plans squared in place, the next step is to decide on location and height based on your plan.
Deciding on Location and Height
Determining where you’ll build your retaining wall is crucial before buying any materials because it greatly affects how high it needs to be. Check with local authorities for permits required before building; once done, marking an area where you intend to build does provide useful insights into what type of retaining wall will work best for your site conditions.
If you’re building a retaining wall to create raised garden beds, place the wall at the top of a slope. This will help prevent erosion and also cut down on the amount of digging you need to do. By doing this, you have a better chance of being ready when planting season arrives.
The height of your retaining wall will depend on what you’re hoping to achieve. For example, if you want to create a small terrace, a two-foot-tall retaining wall might be enough. However, for a steep slope or deep excavations, you may need something higher. An engineer’s opinion may be necessary before deciding on an appropriate height for stability reasons.
Homeowners could be tempted to underestimate how much earth their wall is retaining (even when building it on their own). It’s crucial to understand that the higher the wall, the more pressure it endures from backing soil, which can impact its durability. Therefore, starting with an assessment of the area and required material early in planning could help in making better decisions later in the process.
Next up is selecting the ideal construction materials and types of sleepers for your project.
Choosing the Right Materials
When it comes to choosing materials for your retaining wall, there are various options available in the market. However, not all materials are created equal, and some may work better for your specific landscaping needs than others. Concrete sleepers are the most popular option for constructing retaining walls due to their durability and long-lasting performance. On the other hand, wood and natural stone offer unique aesthetics that might appeal more to certain landscape designs.
Concrete sleepers come in a range of sizes, colours, textures, and shapes that can cater to various styles. Moreover, they are very durable and require minimal upkeep. They are not only consistent in size, but also interlocking enabling easy installation and a streamlined appearance. Additionally, interlocking sleepers also add extra security to the wall.
Natural stone is another popular material due to its rustic appearance. The natural texture and coloration provide an earthy look that complements an outdoor garden or landscape design. While beautiful to behold, natural stones can be challenging to work with as the lack of uniformity requires extra effort when installing them.
Wood or timber has a warm and welcoming appearance that fits well with any garden setting; however, wood will require more upkeep over time than other materials. Wood can warp or rot when exposed to moisture over time – an important factor when considering this material for building a retaining wall.
It is also crucial that you find the right type of retaining wall steel posts for your project. Will you need the standard-sized 100PFC or would you need heavy-duty ones like the 150 PFC, 150UC37, or the 200uc 46?
READ: Weather and Climate Considerations for Choosing Retaining Wall Materials
Let’s say you decide on concrete sleepers – it’s vital not only to go for uniformity of size and shape but also a textured finish that enables traction when wet, ensuring safety and stability.
Building the Retaining Wall Foundation
The retaining wall foundation ensures the stability of the entire structure and safeguards your landscaping from soil erosion. Preparing a solid gravel base and firm backfill is essential to prevent shifting or tilting.
A 6” base of ¾” minus road gravel is recommended, which should be compacted with a large compactor after every 2” of gravel laid.
An uneven base can affect the level of subsequent sleepers.
While some experts may recommend adding additional layers of geotextile fabric on top of the gravel, it may not always be necessary if organic debris is absent in the soil. Sometimes choosing to do this step could negatively impact water flow through the gravel. Always consider factors like climate or if pets are involved; these factors could lead to debris piling up and clogging drains.
Just like a house’s foundation is fundamental to its structural integrity, a retaining wall’s foundation is paramount to ensuring its longevity.
Now that your foundation preparation is complete, it is finally time to start assembling the retaining wall itself!
Digging a Trench and Laying Gravel Base
The foundation of any retaining wall is the most crucial part of the entire process. Without an adequate foundation, your wall won’t be strong enough to hold back soil and water pressure over time. The first step in building a solid foundation is digging a trench. This will give you the necessary depth needed for the gravel base, which is essential for stability.
Before you start digging, make sure to call 811 to locate underground utility lines. Digging without properly locating these lines can result in hazardous situations, including explosions or electrocution. Once you have marked out where you intend to dig your trench, use a shovel or excavator to dig down to the required depth. Remember that the trench should be twice as wide as your retaining wall sleepers.
After digging your trench, it’s time to lay your gravel base.
The key to a stable retaining wall is a solid and well-compacted gravel base. It helps distribute weight evenly across the wall and prevents soil erosion. A layer of at least 6 inches of ¾” minus road gravel is recommended for your base material. Fill up your trench with this gravel every two inches and use a large compactor to compact each layer thoroughly.
Think of it like making a layered cake – each layer needs to be compacted even before adding another layer on top. If one layer is thicker than another or not packed tightly enough, it becomes unstable and can eventually topple over.
Constructing the Retaining Wall
Once you’ve laid your gravel base, it’s time to move on to constructing the retaining wall itself.
Start by placing your first course of sleepers into the trench on top of the gravel base. Make sure that they’re level both front-to-back and side-to-side using a level tool. If they’re not level, your entire wall will be off-balance. Continue to stack sleepers on top of the first course, making sure each course is level before moving on to the next.
One important factor to consider when stacking sleepers is whether or not to use interlocking sleepers. While interlocking sleepers do provide extra security and stability to the wall, they can make adjusting the placement of sleepers difficult once stacked. Non-interlocking sleepers can be less secure but offer more flexibility in adjusting the placement if needed.
When selecting your retaining wall sleepers, it’s essential to choose ones that are appropriate for the height of your wall. Additionally, always purchase 10% more sleepers than you estimated needing, just in case there are any mistakes during installation. Once you’ve finished stacking your retaining wall sleepers, it’s time to backfill.
Backfilling is like packing a suitcase, every inch needs to be filled properly and compacted from top to bottom. Use soil that has good drainage properties behind your retaining wall and add it in layers and compact after each layer.
Following all of these steps carefully is essential if you want to create a safe and long-lasting retaining wall. Take your time throughout the process, ensuring that each step is completed correctly before moving on to the next. Building a retaining wall may be a time-consuming process initially, however it’s an investment for years’ worth of durability and aesthetic appeal – both invaluable in their own right.
Stacking Sleepers and Backfilling
The actual construction of the retaining wall involves stacking sleepers and backfilling. It is important to make sure that the sleepers are level and properly aligned. You will also want to ensure that they are tightly fitted together so that the wall is sturdy and stable.
One tip for ensuring proper alignment of the sleepers is to find a straight edge to guide you during construction. This could be a long piece of wood or metal that you can hold up against the sleepers as you stack them. By using this guide, you can ensure that each block lines up with the next one, which will result in a more even and secure wall.
As you stack the sleepers, be sure to check for levelness frequently. A crooked wall can lead to structural problems down the line, so it’s worth taking extra time to get it right. Use a level to ensure that each course of sleepers is even and well-aligned before moving on to the next one.
Some people prefer to use mortar between their retaining wall sleepers to give extra support and stability. While this can be effective, it also adds time and effort to the building process. Additionally, some DIYers feel that mortar detracts from the natural appearance of their wall. Ultimately, whether or not to use mortar depends on your personal preference and what kind of environment your wall will be exposed to.
Once the sleepers are stacked in place, it’s time to backfill around them. This involves placing soil behind the retaining wall to reinforce it against pressure from gravity and water.
Ensuring Proper Drainage
Proper drainage is an essential element of any retaining wall project. Without adequate drainage, water can build up behind your wall, causing it to shift or even collapse over time. Fortunately, there are several steps you can take to ensure that your retaining wall has the drainage it needs to remain strong and stable.
One of the most important steps in ensuring proper drainage is to include a perforated pipe behind your retaining wall. This pipe will allow water to drain away from the wall rather than building up behind it. Ensure that the pipe is installed at the same level as the gravel base of your wall for maximum effectiveness.
You should also make sure that philtre fabric is installed between your gravel base and soil backfill. This fabric acts as a barrier, preventing soil particles from migrating into the gravel and clogging up your drainage system. Be sure to use landscape staples to hold the fabric in place while you build your wall.
Properly drained soil is also essential for a stable retaining wall. Think of it this way: building your retaining wall on top of soggy, saturated soil is like balancing a giant Jenga tower on top of a wobbly table. By contrast, if you have well-drained soil beneath your wall, it’s like having a sturdy, solid foundation for your tower.
Some people may be tempted to cut corners when it comes to drainage by simply backfilling their retaining wall with whatever dirt happens to be available. But this can lead to serious problems down the line and undermine all of your hard work on the rest of the project. Investing in good quality drainage materials upfront is essential if you want your retaining wall to last for years to come.
With these tips in mind, you’re ready to tackle the construction of your retaining wall! Remember that building a retaining wall takes time and effort but can ultimately pay off in increased property value and more attractive landscaping features.
Installing Perforated Pipe and Philtre Fabric
When it comes to building a retaining wall, drainage is essential to ensuring the stability and longevity of your structure. Without proper drainage, water can build up behind the wall, increasing pressure on the soil and potentially causing the wall to fail. That’s where perforated pipe and philtre fabric come in.
A perforated pipe is a flexible plastic pipe with small holes or slits along its length. It’s used to collect and redirect water that would otherwise build up behind the wall. Philtre fabric, on the other hand, is a permeable material that allows water to pass through while preventing soil particles from clogging the perforated pipe. Together, these two components work to drain water away from your retaining wall and keep it stable for years to come.
To install perforated pipe and philtre fabric, you’ll first need to excavate a trench behind your retaining wall. The trench should be deep enough to accommodate the perforated pipe and wide enough to allow for easy installation. Once you’ve dug your trench, lay landscape fabric down along the bottom, overlapping any seams by at least six inches. This will help prevent any small rocks or debris from clogging your drainage system.
Next, add a layer of ¾” minus road gravel along the bottom of the trench. This will serve as a base for your perforated pipe and ensure that water can easily flow toward it. Compact the gravel with a plate compactor after every two inches of gravel is laid.
Place your perforated pipe into the trench so that it runs along the entire length of your retaining wall. If necessary, cut the pipe to size using a pair of scissors or a utility knife. Make sure that any holes or slits in the pipe are facing downward so that water can flow freely into it.
Now, wrap philtre fabric around the perforated pipe so that it covers the entire length of the pipe. Use landscape pins or staples to hold the fabric in place, being careful not to puncture the pipe. Some builders dispute the necessity of using philtre fabric, stating that it can be easily clogged by fine soil particles and ultimately lead to more drainage problems than it solves.
However, using philtre fabric correctly can go a long way in preventing clogs and improving drainage. Philtre fabric ensures that only water can enter the perforated pipe, while small soil particles are kept out. Over time, even small particles can accumulate and cause blockages in your drainage system, so taking steps to prevent these blockages is critical to proper drainage and wall stability.
To finish your installation, backfill the trench with more ¾” minus road gravel until you’ve reached ground level. Be sure to keep the perforated pipe covered with gravel and avoid compacting soil directly around it, as this could damage the pipe and impact your drainage system.
Installing perforated pipe and philtre fabric may seem like a small part of building a retaining wall, but it’s an essential one when it comes to ensuring proper drainage and stability. By taking care during this step in the process, you’ll help ensure that your wall lasts for years without fail.
Final Thoughts
Building a retaining wall safely and easily is an achievable goal, but it requires careful planning, the right materials, and detailed instructions. As highlighted in our step-by-step guide, the process can be simplified with a clear understanding of the basics and the use of high-quality products. That’s where we at Retaining Wall Supplies come into the picture.
We provide an extensive range of top-quality materials and tools necessary for building a robust, reliable, and aesthetically pleasing retaining wall. Opting for our products and services ensures a smooth, efficient, and safe construction process. Our commitment to customer satisfaction and quality is what sets us apart in the industry. So, please don’t leave the safety and beauty of your landscape to chance, rely on us at Retaining Wall Supplies.
Visit our website and explore our comprehensive range of products and services, including concrete sleepers in Melbourne, that can make your retaining wall construction project easier, safer, and more successful.
