How do you avoid common mistakes and pitfalls when installing a retaining wall?

1 Choosing the wrong materials

Not all retaining walls are created equal. Depending on the height, slope, soil, and drainage conditions of your site, you may need different types of materials and techniques to build a sturdy and durable wall. For example, wood may rot or warp over time, concrete may crack or crumble under pressure, and bricks may shift or collapse without proper reinforcement. You should consult a landscape designer or engineer to help you choose the best materials for your project, and follow the manufacturer's instructions and local codes for installation.

3 Forgetting the frost line

Another common mistake that can compromise the stability of your retaining wall is forgetting the frost line. The frost line is the depth at which the soil freezes in winter, and it varies depending on your location and climate. If your wall is not built below the frost line, it can be affected by frost heave, which is the expansion and contraction of the soil due to freezing and thawing. This can cause the wall to shift, crack, or lean over time. To avoid this, you should dig your wall foundation at least a foot below the frost line, and use a compacted gravel base to prevent moisture from reaching the wall.

4 Skimping on the base

The base of your retaining wall is the foundation that supports the weight and pressure of the wall and the soil behind it. If you skimp on the base, you risk having a weak and unstable wall that can sag, crack, or topple over. To ensure a strong and level base, you should dig a trench that is at least twice as wide as the wall blocks, and fill it with a layer of crushed stone or gravel. You should then compact the base with a plate compactor or a tamper, and check for levelness with a level or a string.

5 Stacking the blocks too high

While you may be tempted to stack your wall blocks as high as possible to create more usable space or a dramatic effect, you should be aware of the limitations and risks of doing so. The higher your wall, the more pressure and stress it has to withstand from the soil and water behind it. This means you may need additional reinforcement, such as geogrids, anchors, or tiebacks, to prevent the wall from failing. You may also need a building permit and a professional engineer to design and inspect your wall, depending on your local regulations. A general rule of thumb is to keep your wall under four feet high, unless you have expert guidance and approval.

6 Neglecting the maintenance

Finally, installing a retaining wall is not a one-time project. You need to maintain your wall regularly to ensure its longevity and performance. This means checking for any signs of damage, such as cracks, bulges, or leaning, and repairing them as soon as possible. It also means cleaning the wall surface from dirt, debris, or stains, and sealing it if necessary. You should also monitor the drainage system and the vegetation around the wall, and remove any obstructions or excess moisture that could affect the wall's integrity.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?