Retaining Walls

Retaining walls are structures which are created to hold back soil on unnatural slopes. They bind soils between elevations in areas where the land needs to be severely shaped. They have textured faces, and thus look like stone as opposed to concrete. They do not require mortar or footings, and are relatively simple to build with the required materials and manual labour.

Strategies

Begin by digging a trench, as deep and wide as the manufacturer recommends. Fill the bottom of the trench with about an inch of sand, and rake it level. Compact with a tamper and then line the bottom and back of the trench with landscape fabric. After this, you can lay the first block. Again, follow the directions of the manufacturer. Check to make sure the block is level, from front to back and side to side. Use a rubber mallet to tap the block if it is not level. Once the first block is in place, you can begin laying the next one, and the next one, and so forth, checking to make sure each block is level on its own and with each other. After the first course is done, begin the second course. Position each block so it crosses a joint in the course below it. Alternate the beginning of the rows with one full block and a half block as you go up. Continue to make sure each block is level. When you reach the 3^rd course, it is time to install some drainpipe. Leave an exit point at the end of the wall for the drainpipe, and tuck it behind the wall. Cover it with gravel and tamp it. As you continue building the wall, keep adding gravel and tamping. When your wall is finished, the last step is to add capstones. Capstones cover the top course. Use construction adhesive on the top of the wall before setting capstones into place. In the space between the top of the wall and the landscape fabric, fill with topsoil.

Key Information

There are a variety of types of retaining walls you can choose from, and before you spend a bunch of money on materials and stones, you need to know which one you want and need. Gravity walls depend on their weight to oppose pressure from behind and have strong stability, although they can topple fairly easily due to the high internal leverage of the earth’s pressure. A piling wall is a wall fixed by soil on both sides of its lower length using long piles. This wall can hold high loads if the piles are able to resist the bending forces. A cantilever wall stabilizes itself using the earth’s pressure that is attempting to topple it. It does so with a second lever arm. Lastly, an anchored wall has cables which drive into the soil or rock and are fixed by expanding anchors, which prevents it from toppling.

Essential Tools

While retaining walls first and foremost need to be functional, they also need to be aesthetically pleasing to the home owner. Your local garden and landscaping store should have a large variety of blocks to choose from. You will also need a tamper; you can purchase either a hand tamper, or rent a motored compacter. Landscape fabric can be purchased from any local garden store and is relatively inexpensive. You will also need a level, a wheelbarrow, topsoil, sand, and gravel to properly install your retaining wall. Drainpipe can also be purchased from your local garden store, but unlike landscape fabric it is fairly expensive.