14/2012 – Basic guide: installing a Terraforce wall

Step by step photographic illustration

NB: When building composite walls of any significant height, it is important to consult an experienced engineer. The law is very strict, with the NHBRC requirement stating that a wall can be built to a height of 1.2m without consulting an engineer, but as a general rule 1.5m for walls no steeper than 70º is also possible.

Any steeper and especially load carrying walls must be designed by a qualified engineer, even if only 1.2m high.

Remember to always ensure a good/correct foundation and that drainage systems are installed. This will prevent any unwanted ground movement that could cause damage to your retaining wall.

Level foundation 1. Prepare a level foundation, gravel or concrete as directed by site conditions ofr installing a wall. Compacted gravel foundations are usually sufficient for structures not higher than one (1) meter. On sloping sites the foundation may be stepped by block height at intervals to suit the slope.
Place row

2. Place first row of blocks to required alignment and ensure that units are level in all directions. A small amount of mortar will assist with accurate levelling on a concrete foundation.

Drain pipe 3. Install drainage pipe with outlet and free draining backfill as specified behind first row of blocks. A length of flexible pipe will assist in setting out smooth curves.
Fill blocks 4. Fill blocks with good quality soil or soil compost mix and tamp lightly. In this instance the rounded face elevation was chosen.
Backfill and compaction 5. Continue construction row by row, while backfilling and compacting the free-draining material, as each row is completed with topsoil infill. In situ or precast interlocking keys to be installed when directed by the engineer.
 Install geogrid-geofabric 6. When specified, install geogrid-geofabric on the compacted backfill and wedge it between the blocks (or cut and fold into blocks) as indicated by the engineer.
Keep compacting 7. Terraced walls must be well founded. Individual foundations as specified or as shown, on a double row of blocks on well-compacted backfill.
Ready for planting 8. The completed installation, ready to be turned into a growing investment by your imaginative choice of plants.
Railing set into blocks 9. The final product
The final product 10. Railing set into blocks