Retaining Wall Blocks for Your Garden: What to Know

Retaining wall blocks are superb for holding soil back from a higher-lying area, keeping a slope from eroding, creating vertical planting spaces, adding to the aesthetic appeal of your garden, and improving garden functionality with terraces instead of slopes.

In this article, we’ll introduce you to the concrete retaining block (CRB) structures, factors to consider when you use them to build a retaining structure in your garden, and basic guidelines on what to do and want to avoid in the process.

What are Retaining Wall Blocks?

Referred to as CRBs, retaining wall blocks are modular units made from concrete, which are installed individually to build a retaining wall. The installation is normally at an angle range of 70-90 degrees, depending on the installation site.

Advantages of Using These Blocks include:

  • Cost-savings.
  • Speed of construction.
  • Low maintenance.
  • Added planting space.
  • Effective erosion prevention.
  • Attractive building material.
  • Garden focal points.

The price of the structure is dependent on factors such as:

  • Open or closed face installation.
  • How high the structure is and at what angle it is constructed.
  • Access to the work area.
  • Whether grey or coloured blocks are used as the coloured ones are more expensive.

Consult with the local authorities regarding building regulations before you commence with the construction of the retaining wall. It’s imperative that the structure is built correctly and that you use quality materials suitable for the particular type of structure that you want to erect. Visit our CRB section for information about our range of CRB units, and download the installation guide here for step-by-step guidelines.

Proper planning is essential to ensure you build on level ground, have enough blocks to complete the retaining wall and that the structure is strong enough to resist the weight of the soil that it must keep back. Keep in mind that once the soil becomes wet, it is also heavier. This should be factored in when you plan the layout and construction of the structure.

Every metre added in height also means more pressure from the soil on the structure. A miscalculation in this regard can cause the structure to collapse when the upper lying soil becomes drenched, leading to mud or a landslide, which can cause property damage in addition to posing a safety hazard.

If you don’t have any building experience, get in professional help from a contractor and engineer. If the structure is short and low, then you can build it yourself or with the help of a contractor. But a higher and longer structure is best done with an engineer’s help.

Ready to Build?

If you’re a DIY expert and have building experience, read on as a few tips are shared below:

  • Choose the right material for the job. Ask our experts for help here in choosing the CRBs for your specific type of structure.
  • A solid foundation provides for sturdiness – the structure is only as good as its support. Download the free manual for installation here
  • Never lay the CRB units on an uneven surface.
  • Choose the angle and keep to it – because the structure leans back into the higher-lying soil, it is less likely to tumble over than a straight vertical structure.
  • Make sure the blocks are properly interconnected to prevent them from moving.
  • Make provision for drainage.
  • Add backfill to make sure there are no empty spaces beneath and at the back of the structure as tightly compacted backfill adds to the strength and stability of the wall.
  • If you use the CRBs to build terrace structures, make sure there is adequate spacing between the structures. If not, the higher-lying structures will add more weight and pressure onto the lower-lying ones.

Ready to Get Started?

Get a free custom quote and advice here on retaining wall blocks for delivery anywhere in Gauteng. You can also call us at  (012) 386 0050 or drop us an email for more information at