How to Build a Retaining Wall

Building a retaining wall in your Melbourne garden is one of the most effective ways to manage sloping ground, improve drainage, and create leveled outdoor spaces. Whether you’re doing it yourself or hiring a professional, it’s important to understand the key steps to ensure the wall is strong, long-lasting, and compliant with local regulations.

1. Plan the Location and Height

Start by marking the exact area for the wall. Most councils in Victoria allow DIY walls up to 1 metre high, but anything above that may require a permit and engineer's approval. Always check local guidelines.

2. Choose the Right Materials

Common options include:

• Concrete sleepers – very durable and great for structural walls
• Timber sleepers – cost-effective but require treatment
• Natural stone – ideal for low-height decorative garden walls

3. Dig a Solid Trench

You’ll need to dig a trench around 1/4 the height of the wall. This trench should be leveled and filled with crushed rock for base stability.

4. Add Drainage Behind the Wall

Drainage is key! Lay a perforated pipe (aggie pipe) behind the wall, wrapped in geotextile fabric. Backfill with coarse gravel to reduce water pressure buildup.

5. Build in Layers

Whether using blocks or sleepers, build from the lowest point and use a level with every layer. Overlap joints when possible.

6. Cap and Finish

Top the wall with caps or timber capping. Clean the area, backfill with topsoil if needed, and consider planting in front.