Fixing another mess of a retaining block wall

Location: 29 Cutty Sark, Plettenberg Bay, Western Cape South Africa
Date: 30 Jauary 2012

This story once again explains why it is better to use a specialized contractor for what seems like to be a simple project...

The owner of this property, was made to believe by his landscaper that this was a simple little wall to be installed and that there was no need to bring in the specialists. Nothing could be further from the truth. Normally the specialist contractor buys in bulk from the manufacturers and would therefore always get a much better price on the blocks. His workers are also skilled in the scope of work and would complete the process in a shorter span of time, allowing in lower production costs. The specialist would be able to give the client sound advice which would prevent future problems and remedial work. Our company issues a standard five year guarantee on our workmanship on completion.

The landscaper, packed the retaining blocks on the natural ground, not even allowing for the most basic requirement of at least one foundation block burried in natural ground. He made the client order the Terraforce L11 rockface block, which is considerably more expensive than the normal L11, and then installs them with rock face covered in the soil, the wrong way around. The wall was further constructed by putting the blocks directly on top of each other not following the manufactures specification stating a minimum of 80 mm set back. Back filling was done without compacting the soil in layers of 160 mm with a rammer. An irrigation system was installed behind the wall causing the not compacted soil to get saturated with water and in the process pushed the wall over.

We started of by removing all the blocks, pipes and filling. A foundation trench of 600 mm wide and 250 mm deep was excavated in the natural ground. The block wall was then installed with the rock face on the outside and the back fill was compacted by rammer. We laid the irrigation pipes on top of the ground so that all leaks can me monitored and no accidental damage, while doing gardening, can occur. The work was completed in two days.

We found no need for a concrete foundation and due to the position of the wall a subsoil drain system was not required. A few before and after pictures are included.

Before

After