Retaining walls have long been used for preventing soil erosion, but have become increasingly popular in recent years due to their beautiful appearance and the sweeping upward trend of DIY projects. From small garden walls to large stone multi-layer retaining walls, there are endless possibilities for style, size, and materials and virtually any vision you have for your hardscape can be accomplished with a little know-how and the right materials. Let’s explore some of the options including a short how-to for those of you interested in basic retaining wall installation. Please note that this is not a replacement for professional advice and for larger hardscaping projects we always recommend speaking to an expert.
There are many areas that can be greatly improved by the addition of a retaining wall and thankfully this is a project that can often be tackled with just some time, hard work, and basic materials found at Reece Aggregates and Recycling and your local home improvement company. Perhaps you have a sloped backyard and dream of a level space to play volleyball or to finally put in that fire pit ring? Or maybe you love the terraced look and dream of a hillside garden? A retaining wall may be just what you need.
If a retaining wall is on your list of DIY projects, then this short how-to will hopefully give you the inspiration you need.
If you like a natural look, our large granite landscape rocks are a beautiful option for terraces and walls. They come in many variations of size and color and are available for pick up and delivery. Always consider the design elements and architectural style of your house when choosing landscaping materials and choose products that complement the existing structures. If you’re looking for blocks or bricks, your local home improvement store or landscaping supply company is sure to have many options to choose from.
The success of your retaining wall depends on how level and sturdy your base is. Measure out the length and width of your wall and dig a trench for your first layer - making sure to dig down 4-6 inches into the soil. In addition, you will need the trench to extend 8" beyond the back of your block to accommodate the addition of drain rock and pipe. Level out the base as well as you can and compact the soil.
Your next step is to add a layer of crushed rock to prevent soil erosion, perfect your grade, and create a strong base for your wall. We recommend using our 1-1/4" Minus Recycled Concrete for this layer. Fill your trench with 2-3” of gravel, adjust and fine-tune your grade making sure that it’s level or sloped appropriately, then compact the gravel.
If you’re using landscape rocks you won’t need a level for this step as the natural variations in size will be perfectly imprecise, but if you choose blocks or bricks you will want to make sure each one is level to the ones laid on each side, and don’t forget to fill in any cracks or spaces with more gravel to hold them in place.
If you'd like your retaining wall to hold up for many years and not buckle over time, it's important to prevent water build up behind your wall. Lay 4" perforated pipe the length of your wall directly behind the first layer of blocks or landscaping rocks and on top of your gravel base. (Remember - your gravel base should extend 8" beyond the back of your block.) Cover your pipe with drain rock. Continue adding drain rock to this area as you build your wall higher. Use filter fabric to separate the drain rock from any soil. Water will now find the rock and work its way down to your pipe and away from your wall.
If using blocks or bricks you will want to stagger your first and second layers. This can be done by using a saw to cut a block in half and using that piece as the start of your next layer starting the end. Be sure to wear hand, eye, and ear protection when cutting at all times. If you don’t own an appropriate tool for cutting blocks you can easily rent one at most home improvement stores.
If you're using blocks you may want to put down a layer of block caps to create a finished look. These should overhang your wall by 1 - 1 1/2 inches and can be secured using construction adhesive. Fill in gaps between blocks or rocks using leftover gravel. If you'd like a more aesthetically pleasing option for filling in the gaps, use our 5/8" Minus Crushed Rock. Next, landscape as desired. We carry topsoil as well as a specialty topsoil blend for lawns.
Now all that's left to do is stand back and admire your work!
As you can see, building a retaining wall is possible with a little know-how and some hard work, and can be a beautiful addition to your outdoor space. If you tackle this project we’d love to hear from you and see pictures of how it turned out!