How To Build a Brick Retaining Wall
A retaining wall is usually built to stop soil from breaking away from earth that has been excavated. It can be built out of many types of building materials such as timber, concrete, rocks, bricks or interlocking blocks. It can significantly alter the contours of your yard or garden. The following steps outline how to build a low brick retaining wall.
Should you need a retaining wall that is greater than .5m in height, you must check with your Local Council as you may need to obtain council permission.
- laser or water level
- cement mixer
Work out where and why you want a retaining wall: is it on your boundary, is it to level your backyard, is it for a garden bed, or is it to stop your house from sliding away?
Decide on your building material. More often than not the decision on the material to be used is an aesthetic one.
Mark the area where the retaining wall is to be built. Dig a 300mm by 300mm trench, place some steel mesh and fill with concrete.
Place mortar on the ground with a “brickies trowel” and your first course of bricks. Lay two courses of bricks side by side with a 50mm gap between the two rows. It should look like the brickwork in a double brick house might look.
Place an agricultural line at trench level behind the retaining wall. Make sure you connect it to the stormwater line (use a plumber).
Waterproof the back of the wall so that water doesn’t mould the brick work.
Backfill to the required height.
If your yard has drainage problems, you're probably best off consulting a contractor. Whatever you do, make sure water doesn't drain toward the foundation of your house.
A retaining wall is like a dam: The higher the wall and the heavier the soil behind it, the greater the pressure on the wall. Most retaining walls over 1 metre and less in some areas are thus subject to some kind of permit process; this is taken more seriously in areas of seismic activity, where walls must be able to withstand shock loads in addition to everything else. Check with your local council for the regulations before you start.
Finally, remove all grass, topsoil and debris, leaving only natural compacted ground.