The primary purpose of a retaining wall is to control the erosion of soil on your property. Left unchecked, the soil could be washed away or accumulate against the side of your home, which can both result in serious issues. Retaining walls are largely used for aesthetic purposes today, as you can customize the materials used to build them to fit your landscaping.
Planning Your Retaining Wall
The first step to building a retaining wall is planning the layout. If the wall design is freeform, use a rope or hose to outline the shape, then mark the outline in the soil with a shovel. If it is straight, mark the soil with stakes, string, and marking paint. When planning the height of the wall, keep in mind that retaining walls larger than four feet often require you to follow local building codes and may need some engineering. Popular building materials are stone brick, concrete, and steel, but check the local codes for any restrictions on materials you can use.
How To Build Your Own Retaining Wall
Although your choice of building materials will depend on your landscape’s appearance and needs, this guide will go through the building process using blocks with interlocking flanges, which make installation easy.
- Prepare the Foundation: Following your wall’s outline, dig the trench. It should be about four to six inches deep and twice the width of the wall’s blocks. Tamp the dirt down and fill the trench with about three inches of paver base. Spread the base and tamp it down as well.
- Begin Setting the Blocks: Before you start the first row, knock off the flanges on the bottom so the blocks will sit flat. Set the first block in place at the end with the lowest elevation. Continue placing each block next to the first, checking regularly that they are level.
- Set the Second Row: You will have to cut the first block with a masonry blade in order to stagger the joints. Place the cut block, making sure the flange is tight against the first row. Check to make sure it is level, and keep installing blocks.
- Add Drainage: For a proper retaining wall, you will need to add drainage behind the blocks after the second row. Put down landscape fabric behind the wall, leaving some excess to reach the top of the blocks. Fill in directly behind the wall with gravel, then continue to build by adding more rows.
- Apply Concrete Adhesive: For the final two rows, apply concrete adhesive to the wall block tops. Set the following row in place. Fold back any excess fabric and fill in with soils and plants.
You don’t have to be a professional landscaper to install a retaining wall. Try out this guide and add an interesting element to your garden today!