Retaining Wall Blocks

Which Block for Which Wall

Garden Wall Curved Face is the smaller unit at 26.3 blocks per square metre of wall face. The
curved face lets consecutive blocks sit at a slight angle without opening a gap at the back of the
joint, which is what allows a wall to follow a radius without cutting. Modernstone is the larger
grand unit at 14 per square metre, so a wall goes up in roughly half the handling, and it comes
with matching splitface caps and corner units so the top and the returns finish properly.

Measuring a Retaining Wall

Work out the face area, which is wall length multiplied by finished height, not the volume of
soil behind it. Then measure the wall length separately for capping, because caps are sold per
lineal metre rather than per square metre. Ordering the whole job off the area is the usual reason
people end up short on capping.

Drainage Is Not Optional

Water sitting behind a wall is what pushes it over. Put drainage aggregate behind the blocks
and run an ag line at the base, out to daylight or a pit, on every wall regardless of height. Dry
stack blocks are more forgiving than a mortared wall because the joints let some water through,
but they are not a substitute for drainage.

When You Need an Engineer

Height, the slope behind the wall, the soil type and whether anything is built or driven near
the top all change what a wall has to resist. Most councils set a height above which a retaining
wall needs engineering and approval, and the threshold differs between them. Get advice before you
build anything beyond a low garden edge.

Building a New Wall or Facing an Old One

These blocks build the wall itself. If the wall already exists and you want to change how it
looks, retaining wall cladding
is the product for that, and it is a different job entirely.