Why do cheap retaining walls fail?

Most retaining wall failures come from the parts you can't see — posts set too shallow, not enough drainage aggregate behind the wall, no geofabric, and poor waterproofing or backfilling. The wall looks fine on day one, but years later water pressure and saturated soil cause it to move, bulge or fail.

How much drainage aggregate should sit behind a retaining wall?

We install a minimum of 300mm of drainage aggregate behind our walls, running from the base all the way up, leaving only enough room at the top for topsoil and turf. Skimping on this is one of the most common — and most damaging — shortcuts.

What questions should I ask before accepting a retaining wall quote?

Ask how deep the posts will be, how much drainage aggregate is included, whether geofabric is included, what drainage provisions are being installed, whether spoil removal is included, and whether the full scope of works is clearly outlined. A detailed quote should spell all of this out.

Do you provide free retaining wall quotes on the Gold Coast?

Yes. We offer an obligation-free site visit and a detailed, transparent quote that explains exactly what's included and why. Call John or Chelsey on 0487 193 085.

Cheapest Retaining Wall Quote Can Cost the Most

We were recently contacted by a customer who had concerns about a retaining wall after it was completed.

It's a good reminder that when it comes to retaining walls, the things you can't see are often more important than the things you can.

Retaining wall with water staining running down the face — looks fine but has hidden problems — Looked fine from the driveway — but the problems were all in the parts you can't see.

Unfortunately, some contractors reduce costs by cutting corners on the hidden parts of the job. This can include installing posts too shallow, reducing the amount of drainage aggregate behind the wall, omitting geofabric, or taking shortcuts with waterproofing and backfilling.

The problem is that these shortcuts aren't obvious when the job is first completed. The wall might look great on day one, but retaining wall failures often happen years later when water pressure builds up, soils become saturated, or the wall starts to move.

Turf peeled back behind a retaining wall revealing little to no drainage aggregate — Turf laid almost straight onto soil behind the wall — barely any drainage aggregate where there should be 300mm.

Base of retaining wall with a thin white drainage pipe and no proper drainage zone — The drainage at the base of the wall — nowhere near enough to handle Gold Coast downpours.

Poorly installed drainage pipe junction running into a surface drain — Shortcuts in the drainage and backfilling — exactly the parts you can't see once it's finished.

At Sollid Solutions, we don't believe in shortcuts

We install retaining wall posts to appropriate depths based on the wall height, soil conditions, and site requirements.
We install a minimum of 300mm of drainage aggregate behind our retaining walls, extending from the bottom of the wall all the way to the top, leaving only enough room for topsoil and turf preparation.
We use geofabric to prevent soil migration into the drainage zone.
We install black plastic membrane behind the wall where appropriate to help protect the structure and improve its longevity.
We understand that water pressure is one of the leading causes of retaining wall movement and failure, which is why we take drainage seriously.

Galvanised channel bracket lying loose on the ground beside the retaining wall — Fixings left loose and exposed — small details, but they tell you how the rest was done.

Close-up of a cracked and spalling concrete edge on the retaining wall, circled in red — Cracking and spalling already showing along the concrete edge — and this wall isn't old.

Retaining wall meeting the driveway edge with movement and gaps starting to show — Where the wall meets the driveway — gaps and movement already creeping in.

When comparing quotes, don't just ask for the final price

Ask:

How deep will the posts be installed?
How much drainage aggregate is included?
Is geofabric included?
What drainage provisions are being installed?
Is spoil removal included?
Is the scope of works clearly outlined?

A detailed quote should tell you exactly what you're getting.

At Sollid Solutions, we believe our clients deserve transparent, comprehensive quotes that clearly explain what's included and why it's necessary.

Because a retaining wall isn't just about how it looks when it's finished — it's about how it performs after years of rain, soil pressure, and changing ground conditions.

Before accepting a quote, compare apples with apples

If you're planning a retaining wall project on the Gold Coast, we'd be happy to provide an obligation-free site visit and detailed quote. Call John on 0409 494 096 or Chelsey on 0487 193 085.

We're glad that's not our wall in the pictures above, and our heart aches for this customer and their hip pocket.

Sollid Quotes, Sollid Solutions.

The Cheapest Quote Can End Up Being the Most Expensive

At Sollid Solutions, we don't believe in shortcuts

When comparing quotes, don't just ask for the final price

Need a quote on your job?

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