Installation

While Wonder Walls can arrange for the installation of your retaining wall, if you choose to do it yourself, there are some things you need to know! Comprehensive step by step installation instructions are available on request.

Installation dos and don’ts:

• Backfilling behind a wall can only be done once the postholes themselves have been backfilled for at least 19 hours.
• Backfill is to be clean sand only.  Backfill containing any other material i.e. rubble, stone, tree branches etc. is likely to cause damage to panels.
• Mechanically backfilling any closer than a distance equal to the height of the wall is not allowed unless the wall is adequately propped at the posts and at the centre of the panels during compaction.
• In all cases compaction must be only done in no more than layers of 300mm at a time.

A precast concrete post and panel retaining wall system is designed to hold up properly compacted earth.  It is not able to hold up any surcharge loading without running the very real risk of damage that would later require remedial work.

This surcharge loading includes the following:

• Pay loaders, heavy machines or brick carters driving along the top of the backfilled wall.
• Heavy loads being deposited immediately behind the wall e.g. pallets of bricks.
• Use of the retaining wall as a base for constructing scaffolding or framework.
• Fencers using the panels as leverage points when installing a fence. 
• Fence posts with concrete footings need to have a cushion of sand between footings and the panels.

The retaining wall could be damaged should any of the above occur.

Lastly, the concrete posts resting in properly compacted ground hold up this system of retaining.  Drainers, in particular, must avoid undermining retaining walls when trenching or installing pipes.  If the sand in front of a wall is removed and not replaced, or replaced loosely, then the pressure of the sand behind the wall could push the posts forward.