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Building a retaining wall may look simple from the outside, but behind every strong, long-lasting wall is a detailed process involving planning, engineering, drainage management, and skilled construction. Whether you’re planning a sandstone wall, a bush rock feature, or a large structural retaining wall, understanding the process can help you know what to expect – and why choosing experienced professionals matters.

Here’s a clear breakdown of how retaining walls are built from start to finish.

Step 1: On-Site Consultation & Assessment

Every successful retaining wall starts with a thorough site assessment. During this stage, we look at:

  • The slope and gradient of the land
  • Soil type and stability
  • Drainage issues or water flow patterns
  • Access for machinery
  • The purpose and desired style of the wall

This helps us determine the best material and construction method, and ensures the final design suits both your property and your budget.

Step 2: Design, Quote & Material Selection

Once the site is assessed, we prepare a tailored design and quote. We discuss:

  • Wall height and length
  • Whether engineering or council approval is required
  • Your preferred look (sandstone blocks, bush rock style, natural vs. cut stone)
  • Structural requirements and drainage plans

Because Retaincon specialises in sandstone and bush rock retaining walls, we guide you through material options that deliver both strength and a natural, timeless look.

Step 3: Engineering & Council Approvals (if required)

Depending on the height, location, and structural load of your wall, you may need:

  • Structural engineering certification (Form 15 / NSW Certificate)
  • Local council approval

Typically, approvals are needed for walls over 1 metre high, walls built near a boundary, or walls supporting extra loads like driveways or fences.

The good news?
We manage this entire process for you, including engineering designs and submitting all relevant paperwork, so you don’t have to deal with the council directly.

Step 4: Excavation & Site Preparation

With approvals complete, construction begins.

We prepare the site by:

  • Removing vegetation, old walls, or unstable soil
  • Excavating to create a stable foundation
  • Leveling and grading the base
  • Preparing access for machinery and materials

A strong retaining wall depends heavily on a solid, well-prepared foundation – this step cannot be rushed.

Step 5: Drainage Installation

Drainage is one of the most crucial components of any retaining wall. Without proper drainage, water builds up behind the wall, increasing pressure and causing movement or failure over time.

This stage includes:

  • Installing drainage gravel
  • Laying geofabric
  • Adding perforated (agg) pipes
  • Creating outlets for water release

We always prioritise drainage to ensure long-term performance, particularly in areas with high rainfall or clay-heavy soils.

Step 6: Construction of the Wall

Now the real transformation begins.

Using sandstone or bush rock, we carefully construct the wall according to engineering specifications. This includes:

  • Strategic placement of stones for strength and visual appeal
  • Layer-by-layer building with proper compaction
  • Checking alignment and stability throughout construction

With bush rock walls, each stone is selected and positioned, creating a unique, natural finish.
With sandstone blocks, we achieve a more structured, architectural look.

Step 7: Backfilling & Compaction

Once the wall structure is complete, we backfill behind it using suitable materials. Layered compaction is essential for preventing future movement.

This step may also involve:

  • Final drainage checks
  • Adding topsoil for landscaping
  • Preparing garden beds or turf-ready areas

Step 8: Final Inspection & Handover

Before we consider the job complete, we conduct a full final inspection to ensure:

  • The wall meets all engineering requirements
  • Drainage systems are functioning
  • All work is compliant with relevant standards
  • The site is clean and ready for use

You receive the necessary certification (if applicable) and peace of mind knowing your retaining wall is built to last.

A Smooth Process from Start to Finish

At Retaincon, we specialise in natural stone retaining walls – sandstone and bush rock – across the Gold Coast, Northern NSW, Sunshine Coast, Scenic Rim, and surrounding regions.


We handle everything from design and approvals to construction and finishing, ensuring your wall is both beautiful and structurally sound.