Concrete Sleeper Retaining Walls

Why choose concrete sleepers?

• •Durability. Concrete sleepers don't rot, and termites won't eat them the way they can attack untreated timber.
• •Strength. Steel posts and reinforced sleepers can retain significant soil loads when designed and installed correctly.
• •Slim footprint. A sleeper wall takes up less space than a sloping batter or a wide block wall.
• •Finish options. Plain, smooth, sandstone-look, timber-look and coloured sleepers are available from suppliers.
• •Staged construction. Walls can be extended or raised in stages when designed for it.

Permits and engineering

Retaining walls aren't just landscaping. A failed wall can damage property and injure people. In Victoria, retaining walls of 1 metre or more in height generally need a building permit, and walls of that height are typically designed by an engineer. Other factors can also trigger the need for approval or engineering, even for lower walls, including:

• •loads above the wall, such as a driveway, shed, pool or house footing;
• •walls close to a boundary or supporting a neighbour's land;
• •sloping ground behind the wall;
• •walls near easements or drainage lines.

Before quoting, we'll talk about wall height, what sits above and below it, and whether a permit and engineering are likely to be needed. Where they are, we build to the engineer's design, including post size, embedment depth, footing diameter and spacing.

Drainage: the key to a lasting wall

Water pressure behind a wall is one of the main reasons retaining walls lean or fail. A properly built sleeper wall includes:

• •Agricultural drain (ag pipe) at the base of the wall, behind the sleepers, to collect water.
• •Free-draining gravel backfill behind the wall so water can reach the drain.
• •Geotextile fabric to stop soil clogging the gravel.
• •Discharge to a legal point. The ag pipe should connect to a suitable stormwater point rather than simply dumping water onto a neighbour's property.

How we build a concrete sleeper wall

1. 01Set-out. We confirm the wall line, height and end treatments, and locate services and boundaries.
2. 02Excavation. The ground is cut back where needed to make room for the wall and drainage.
3. 03Post holes. Holes are drilled or dug to the depth and diameter required by the design.
4. 04Set posts. Galvanised steel posts are set plumb, aligned and spaced to suit the sleeper length, then concreted in.
5. 05Install sleepers. Once the footings have gained enough strength, the sleepers are slid into place between the posts.
6. 06Drainage and backfill. Ag pipe, geotextile and gravel are installed as the wall is backfilled.
7. 07Finish. Post caps, end treatments and any garden beds or paths along the wall are completed.

Working with slopes and levels

Sleeper walls are often part of a bigger plan: levelling a play area, creating a flat pad for a shed, terracing a garden, or supporting the edge of a driveway or patio. On sloping blocks, stepped walls with garden beds between them can look softer than one tall wall and may reduce individual wall heights. Steps through the terraces tie the levels together. See concrete steps and stairs, shed slabs and concrete patios.

Where retaining walls are common

Retaining walls are a common need on sloping blocks such as those in Ferntree Gully, Boronia, Lysterfield, Lysterfield South, Endeavour Hills and Wheelers Hill. Walls are also used on flatter blocks in Rowville and elsewhere to raise garden beds, define boundaries or level cut-and-fill sites after building work.

Replacing timber walls

Many older timber sleeper walls eventually rot, lean or bulge. Replacing them with concrete sleepers is a common upgrade. The old wall is removed carefully so the soil behind it doesn't collapse, drainage is installed, and the new wall is built to suit the height and loads.

Related services

For all retaining options, see the retaining walls hub. For slabs and paths behind or in front of the wall, see the slabs hub and the pathways and footpaths hub. Our locations page lists every suburb we service.