Retaining walls
Concrete sleeper walls, engineered where they need to be, with the subsoil drainage built in behind every one as standard rather than sold as an extra.
What it costs
Retaining walls are priced on the face area of the wall, which is its length multiplied by its height. Here is what that works out to for common sizes, in plain grey concrete sleepers on a site with machine access and normal soil.
| Wall | Face area | Price (inc GST) |
|---|---|---|
| 15 m long, 0.8 m high | 12.0 m² | from $7,900 |
| 20 m long, 1.0 m high | 20.0 m² | from $13,100 |
| 30 m long, 1.0 m high | 30.0 m² | from $19,600 |
One rate across Brisbane and the Gold Coast. Add-ons are priced separately on top and are not in these figures: stairs, safety barrier, demolition of an old wall, engineering, certification, deep cut, stormwater connection, spoil cartage, travel beyond 50 km and skips.
Short walls are quoted on their own. A wall under about 10 m² costs nearly as much to set up as a longer one: the same machine, the same service location, the same crew mobilisation. Rather than publish a per-metre price that does not hold on a small job, we quote those individually after a look.
What is always included
- Subsoil drainage behind the wall. Standard on every wall we build. A retaining wall without drainage behind it is holding back water as well as soil, and that is what makes walls fail.
- Backfill and compaction in layers, not one dump and a stomp.
- Service location before digging, with the relevant authorities, as a priced step.
What costs extra, and why
- Engineering, for walls over 1 metre. Required, and we build it into the quote rather than discovering it later.
- Building approval and certification, where the height or siting triggers it.
- Stairs and safety barrier. A barrier is required where there is a drop people can fall down.
- Demolition of an existing wall, including removing old sleepers or blocks.
- Stormwater connection, where the subsoil drain has to be piped to a legal discharge point rather than daylighted.
- Difficult access or rock. No machine access changes a wall from a machine job to a hand job, which is a very different number.
We do not excavate deeper than 2 metres, and we do not work on public roads or road reserve. Where a wall needs a deeper cut than that, it needs a contractor set up for it and we will tell you so rather than take the job.
Common questions
Generally, walls up to a metre on your own land and clear of boundaries and services do not. Over a metre, or near a boundary or a structure, usually does. We check yours before quoting.
Because soil holds water, and saturated soil is far heavier than dry soil. Most failed walls we get called to did not have a working subsoil drain behind them. Ours is standard on every wall.
We build concrete sleeper walls. Timber is cheaper up front but has a much shorter life in the ground here, and we would rather not build something we expect to be replaced.
Yes. Stepped and sloping walls are normal on Gold Coast blocks. It changes the set-out and the hours, which we price after seeing the site.
No. We run one rate across both, set at the midpoint of the Brisbane and Gold Coast market rates, so you pay the same wherever you are.
Not as part of this. We can point you to someone who does.
Get your wall priced
Send through the rough length and height, and a photo of the slope. We will work out the engineering position and give you a fixed price.