10 Things You Must Know About Retaining Walls
Building a retaining wall can be a big investment of time and money. Before you get started, learn these key tips to make sure your project is a success.
1. Incorporate the Wall Into Your Lifestyle; Retaining walls are usually thought of as utilitarian and for merely holding back soil. But you can use them to create beautiful outdoor living spaces and incorporate multi-use spaces.
2. Make a Creative Design; Retaining walls don’t have to be perfectly straight. Add a curve to dress up a boring straight wall and to add a little more texture to your landscape. You can use a garden hose or large rope to set the layout of the curve, then use a shovel to cut through the soil to follow the curve.
3. Size Does Matter; Smaller retaining walls, such as those less than four feet, can be easily planned and created without worrying too much about structure. Larger walls above that height may need an engineer’s touch. Also be sure to check with local codes before starting one more than four feet tall.
4. Think Terracing; From a lower grade, you’ll need to gradually step up the retaining wall to reach a greater slope. Do this in increments and plan for a slight offset for each course change.
5. Manufactured Blocks and Stones Are Easier; Besides offering a consistent look, manufactured blocks and stones for retaining walls offer structural integrity and an even base with which to work. There is little guesswork in installing, plus you’ll have less work to do making sure each course is level. Be sure to color match and space out uneven colored stones and blocks for a better look.
6. Create A Solid Base; Dig out your base several inches below grade and tamp/compact it to level. Add any filler, such as gravel, before adding your first stones or blocks. Remember, the base sets the tone for the entire wall, so spend a lot of time in preparing this key component.
7. Plan For Drainage; A retaining wall that has a slope dropping to it will need additional drainage at the base. Add gravel and a fabric-covered drainage pipe at the base. The fabric will help prevent clogging of the pipe — a key feature as you will not want to dig out the pipe later to unclog it.
8. Keep It Level; For each course of stones and blocks, be sure to check for level. This will help maintain a sturdy and balanced wall, plus you’ll keep an even and consistent look.
9. Backfill Adds Support; Backfilling as you go adds support in success layers, so as you add a new course of blocks or stones, backfill to match this level. Be sure to tamp in/compact the soil as well, so you don’t have as much settling later.
10. Add Finishing Touches to the Top; Add cap blocks to the top row of a block or stone retaining wall. You can add a layer of masonry adhesive to hold them in place, then back fill. Or you can backfill as you go, then add the cap. Either way, it provides a nice finished look, much like edging added to a paver patio.