Retaining Wall Questions, Answered for Perth

Choosing a wall

What is the best type of retaining wall for a Perth garden?

There is no single best wall. For most suburban boundary walls and terraces, limestone and concrete sleeper walls are the usual choices. Timber sleepers suit low garden walls and raised beds. Taller walls and walls carrying driveways or buildings usually call for an engineered block or masonry wall. The right choice depends on height, space, look, budget and what the wall supports.

Limestone or concrete sleepers?

Limestone is heavier and more traditional, and blends with most Perth gardens. Concrete sleeper walls are slimmer, which helps on tight boundaries, and are easy to put a fence on. Both work in sand when built properly. Cost depends on the site, so ask for both to be priced if you are undecided.

How long should a retaining wall last?

A well-built masonry or concrete wall with working drainage should last for decades. Timber walls have a shorter life. The biggest factors are drainage, the footing and whether the wall is asked to carry more than it was designed for.

Ground, water and drainage

Why does drainage matter so much in sand?

Sand drains well, but water still collects behind a wall after heavy rain, especially where fine material has built up or the ground below is denser. Saturated ground pushes much harder on a wall than dry ground. A slotted pipe, free-draining gravel and fabric to keep sand out are cheap compared with rebuilding a failed wall.

Where does the water go?

It needs an outlet: a soakwell, a garden area that can take it, or another suitable point. It should not simply be sent onto a neighbour's property. Ask the builder to show you where the pipe will discharge.

What if there is limestone or rock under my block?

It is common, particularly near the coast and in the hills. Rock can make excavation slower and may need a rock breaker, which affects the price. It can also provide a firm base. A site visit is the only way to know.

Height, approvals and boundaries

Do I need council approval?

Possibly. Height, position, what the wall supports and which local government you are in all matter. Our council approval guide explains the questions to ask. Always confirm with your council before work starts.

Can I build a retaining wall on the boundary?

Yes, boundary walls are common in Perth. Talk to your neighbour first, check whether approval is needed, and put any agreement about access, fences and cost in writing.

Can a fence go on my retaining wall?

Usually, if the wall is designed for it. Fences add wind load to the top of the wall. Tell the builder at the quote stage.

Cost and timing

How much will my wall cost?

See the retaining wall cost guide for 2026 planning ranges. Your quote depends on wall type, size, access, excavation, drainage and any engineering or approvals.

How long does a wall take to build?

A short, low garden wall might take a day or two. A long boundary wall, a wall needing engineering, or a job with difficult access can take considerably longer, and approvals add time before work starts. The builder will give you an estimate with the quote.

Is there a best time of year to build?

Walls can be built year-round in Perth. Dry months make excavation in sand easier and avoid rain delays, but builders are often busier then. Winter jobs need extra care with open excavations and drainage during wet spells.

What should a retaining wall quote include?

At minimum: the wall type, height and length, the footing, the drainage behind the wall and where it discharges, excavation and spoil removal, and any fence, steps, engineering or approvals. If something is missing, ask whether it is included before you compare totals.

Do I need to be home for the site visit?

Not always. Builders usually prefer to meet you so they can talk through what you want, but many can measure and assess the site on their own as long as they can get to the wall and reach you by phone.

Repairs

My wall is leaning. What should I do?

Keep people and vehicles away from the low side, take photos, and get it looked at. Our repairs page explains the usual causes and options.

Can part of a wall be fixed without replacing all of it?

Often, yes, if the rest of the wall is sound and the cause can be fixed. A builder will assess the whole wall before recommending a repair or rebuild.