Building a garden barrier involves more than layering retaining wall blocks. You need to consider how water will move around and through the structure. Proper drainage is necessary to keep your wall strong and straight. Erosion can cause imbalance and weak points while shifting ground can create cracks and other damage.
Two Types of Retaining Walls
All retaining walls fall into one of two categories: permeable and impermeable. The former refers to structures that allow water to flow through while the latter does not.
- Permeable Wall Facts
Permeable structures include gravity block walls, sleeper walls, and rock-filled steel mesh baskets called gabions. A drainage layer will still be needed behind this type of retaining wall to keep the path clear for each seepage point. It also allows dirt to wash away rather than staining the brick face. As an added measure, you can also install a drainage pipe in case of pressure buildup.
- Impermeable Wall Facts
Impermeable structures include block or brickwork walls, reinforced concrete walls, and sleeper walls with plastic backing. These require provisions for drainage to prevent damage over time. Weep holes can be added or builders can install agriculture pipe that’s perforated or slotted. Both permit moisture to drain so that it doesn’t accumulate in the structure.
Building a Drainage Layer for Your Retaining Wall
It’s important to remember that retaining walls are more than columns of bricks or concrete. They require adequate drainage or they will fail. When installing a drainage layer, use at least 100mm of gravel that’s 10mm or smaller. Ordinary soil is not a good choice for backfill material when building a drain.
A perforated pipe is a helpful tool that can prevent build up during heavy rain or when watering the area. If you plan to add a pipe, then the layer should be 50 to 100mm larger than the diameter of the pipe.
Buy Retaining Wall Blocks & More
ABC Brick Sales offers all the materials you need to build a beautiful, functional retaining wall. We carry a wide variety of retaining wall blocks as well as other supplies you need to provide proper drainage. Our experts are available to answer questions and help you make the best choice when it comes to sizes and layout. Visit one of our four showrooms or get in touch with our friendly team. Let us help you make your retaining wall project a success!