8/2024 – Steps to follow for a professional result

September 6, 2024/

Want to get the best possible result for your retaining wall? We’ve got you covered!

Just follow these simple steps to ensure your wall not only looks great but lasts for years to come!

An overview of the process

Firstly, decide what you want to achieve, possibly with a layout sketch and a cross-section drawing. Next, your local supplier will provide prices and a reference to recommended installers with experience in the construction of Terraforce retaining walls:

Ensure that, where required, a proper design has been prepared to submit to your local municipality. Some installations are deemed pure landscaping measures and would not require the submission of plans. Confirm with the local authority what their regulations are. Should your recommended installer not be able to assist with these questions, find a new one.

During the construction phase, ensure that the designer of the approved plans visits the site to ensure that his specifications are met.

After completion of the wall, obtain a completion certificate as prescribed by SANS 10400 Form 4 (if required) and hand it to the building inspector.

To help your designer work efficiently and avoid delays, it’s important to provide the right information upfront. This includes a cross-section sketch, or multiple cross sections, if the wall has varying heights (in 1m height intervals), showing the following information:

Terraforce cross section, hand sketched
Terraforce cross-section, hand sketched
Checking on inclination
Checking on inclination

Steps for a comprehensive cross-section

  • Height of wall and inclination of the fascia, in degrees. Walls at say 65-degree inclination are more cost effective than steep walls at say 85 degrees.

  • Type of native soil found on site, at foundation level and on the slope to be retained. Photos may help the designer to assess site conditions.
  • Is the ground behind the wall level or is it rising further? Photos will help if the designer is unable to visit the site.

  • Indicate any surcharge loading, such as a building or a driveway, above the wall and indicate the distance between the load and the top of the wall.

  • Steep and high walls often need geogrid reinforcing incorporated into the backfill for stability. Indicate the space available behind the block fascia and the cut face to incorporate such measures.
  • Any groundwater visible? The most common reason for failure of gravity or block retaining walls are the buildup of pore water pressure in the retained soil. Trapped water needs to escape via an agricultural drain.
  • If there is a possibility of surface water above the wall to drain towards the wall. Ideally, all surface water needs to be directed away from the wall and should not be allowed to spill over.
  • Items 6 and 7 above will have a major effect on the stability of the wall and needs to be address

Contractors’ checklist

We recommend that a Terraforce recommended contractor be engaged to ensure the best result: Contractors – Terraforce.

Terraforce site inspection in Durban
Terraforce site inspection in Durban
Al Aamal Constrcution, Terraforce recommended contractor, Dubai
Al Aamal Construction, Terraforce recommended contractor, Dubai

Below are some guidelines for the contractor on site:

  • All materials intended to be utilized in the construction of the wall, to be submitted to the Engineer for approval, prior to utilization.

  • DPC density test results to be recorded and approved.

  • Placed on site concrete to be strictly to specification.

  • Location plan for testing sites to be provided.

  • Notify Engineer of tests to be conducted for oversight where required.

  • Ensure that CRB’s (concrete retaining blocks) on site are to specified strength and size. Downloads – Terraforce

  • Follow installation instructions provided by Terraforce. Installation Info – Terraforce

  • If specified, submit sample and spec-sheet of geogrid/geofabric.

  • Install geogrid/geofabric to protrude slightly beyond the blocks for inspection, to be trimmed off after final structural inspection.

  • Setting out of foundation and profile of the wall, preferably to be undertaken in the presence of client or his engineer.

  • Proposed wall position to be clearly marked and confirmed in writing, with a photo record to avoid unnecessary disputes.

  • Always ensure that the supplier of your Terraforce blocks is reputable and a licensed manufacturer, able and willing to provide adequate design back-up or who can refer you to a qualified engineer. Licensed Terraforce Manufacturers

Terrasafe to the rescue!

Typical cross section of beach front protection with Terraforce blocks
Terrasafe typical cross-section of beach front protection with Terraforce blocks
Terrasafe typical cross-section for near vertical Terraforce wall in the UK

Still feeling unsure about the next steps? No worries! Take advantage of Terrasafe, our professional design service. Let us help you create a durable and stunning retaining wall that meets your needs with expert precision: Terrasafe – Terraforce

Terrasafe provides a first-class engineering, management, and specialist technical service to users of any of the Terraforce® products. We aim to set industry gold standards and make a significant contribution throughout South Africa and the world.

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