Top 5 Retaining Wall Materials
for the Illawarra

Retaining walls are one of the most important structural elements in Illawarra gardens. With the region's hilly terrain, heavy coastal rainfall and clay-heavy soils, choosing the right material isn't just about looks — it's about longevity and safety. Here are the top 5 options we recommend.

1. Sandstone

Sandstone is the gold standard for Illawarra retaining walls. Its warm tones complement the natural bush and coastal environment, and when properly installed with drainage, it can last 50+ years. It's ideal for walls up to 1.2m in height and pairs beautifully with native plantings.

2. Besser Block (Concrete Masonry)

Besser block walls are the workhorse of the Illawarra. They're engineered for structural strength and can be rendered, painted or faced with stone veneer for a premium finish. For walls over 1.2m requiring engineer certification, besser block is often the go-to choice.

3. Timber Sleepers

Hardwood or treated pine sleeper walls are popular for garden beds and lower terracing. They're warm, natural and work well with the Illawarra's bush aesthetic. We always recommend treated hardwood over pine for coastal areas, as the salt air can accelerate deterioration.

4. Gabion Baskets

Wire mesh baskets filled with local stone — gabion walls are having a moment in modern Australian landscape design. They're permeable (great for Illawarra drainage issues), incredibly strong, and develop a beautiful natural look over time as plants colonise the gaps.

5. Reinforced Concrete

For large engineered retaining walls — particularly on steep blocks in Thirroul, Scarborough or Austinmer — reinforced poured concrete is often the only option. These walls require structural engineering documentation and council approval, but they'll last the lifetime of your property.