What is the cheapest retaining wall material in 2023?

Garden makeovers can be expensive, and not all of us have large budgets. If you're looking for ways to save money, knowing about the cheapest retaining wall materials can be useful.

To help you make an informed decision, this article looks not only at the cheapest option but also the other considerations you should make when choosing your retaining wall material to make sure it's safe and will last.

• What is the cheapest retaining wall material?
• What you need to know about retaining walls
• Choosing retaining wall materials
• Cheap retaining wall ideas
• Can I build a DIY retaining wall?
• Getting quotes for cheap retaining walls

What is the cheapest retaining wall material?

Retaining wall materials vary in price from relatively cheap to very expensive. Treated pine tends to be the cheapest retaining wall material from around $250 per square metre, but it has its drawbacks too.

If a retaining wall is professionally installed, it should cost (per square metre):

• $250 to $350 for treated pine
• $300 to $450 for hardwood timber
• $300 to $550 for sandstone blocks
• $450 to $700 for reinforced concrete blocks
• $550 to $750 for concrete Besser blocks

The price variation will depend on the complexity of the job. If it's a flat surface and nothing needs to be removed, the installation will cost less. If the surface is uneven or blocks of stone need to be removed, the retaining wall cost will be higher.

In order of price, these are some retaining wall cost ideas for different materials.

Timber retaining walls

• Treated pine is the cheapest retaining wall material at $250 to $350 per m2, but it won't last as long as other materials. If galvanised posts are installed between the treated pine, this will extend the life of the retaining wall.
• A hardwood timber retaining wall costs more than treated pine at $300 to $450 per m2, but will also be more durable. Make sure your timber is treated to a grade that makes it stand up to the dirt and water it will be holding back.
• Railway sleepers are a similar price to treated hardwood and are built to withstand ground and water contact.

Concrete retaining walls

• Interlocking concrete blocks come in a variety of options and prices, ranging from $450 to $700 per m2. They should be reinforced for extra durability.
• Concrete sleepers and Besser blocks can be more expensive at $550 to $750 per m2, but they have a long lifespan.
• The cost of a concrete retaining wall also varies depending on whether you install galvanised steel or concrete posts, which affect its durability and appearance.

Stone retaining walls

• Sandstone blocks range in cost from $300 to $550 per m2. If the stone is cut, it can be most expensive.
• Stone veneer is a cheaper alternative to a full stone retaining wall, costing from $150 to $250 per m2. Natural stone boulders can also be cheaper than cut stone.

What you need to know about retaining walls

Retaining walls in Australia must comply with regulations to ensure they are capable of holding back tons of dirt and have adequate drainage for when it rains.

Your retaining wall must be designed by a structural engineer if it is over a certain height, depending on your state:

• In NSW, retaining walls over 600mm in height requires council permission
• In Queensland and Victoria, retaining walls over one metre in height require council permission
• In some areas, 800mm is the maximum height before council permission is needed

Other restrictions include:

• Retaining walls must be at least 60cm to 1.5 metres away from an adjoining property, depending on your state
• Retaining walls must be at least 50 metres from a natural body of water

Other restrictions may apply, so check with your local council to find out what can and can't be done in your area. Also be aware that if council approval is needed, you will probably need to hire a structural engineer to design the project. Getting approval for retaining walls can be time consuming, but it's best to go through the official channels to avoid problems.

Choosing retaining wall materials

When you're trying to save money on your project, keep in mind that choosing the cheapest retaining wall material may cost more in the long run. Treated pine and even hardwood won't last as long as concrete or natural stone.

Rather than make price the first consideration, look at your property and decide which type of retaining wall would look best in your garden. You should also consider the height of the wall needed and whether you need a heavy duty retaining wall.

Timber

With wood, you may have to replace the retaining wall in 20 years, whereas a stone wall could easily outlast your lifetime. To be sure you get a long-lasting treated pine retaining wall, it should be rated HR5, which makes it highly water and pest resistant. Anything less than HR5 won't last as long, and you may need to replace the retaining wall much sooner.

Concrete

Interlocking concrete blocks are versatile in appearance, with a choice of straight or curved blocks and corner blocks and capping also available. Concrete can be grey or coloured to achieve different effects, including textured options that resemble natural stone. Rendered concrete will cost more, but leaves a beautiful finish.

Natural stone

Natural stone is another perennial favourite. Natural boulders cost about the same as treated pine or concrete blocks, while cut stone can be much more expensive. Sandstone blocks can be ground and reconstituted to make them more regular in shape and easier to work with. Brick retaining walls are another popular choice.

Read more: Concrete vs timber retaining walls

Cheap retaining wall ideas

If you have a strict budget and want to make sure your retaining wall doesn't eat too much of that, there are other ways to save money on your project besides choosing cheap retaining wall materials.

The size of your retaining wall will dictate how large your bill will be. If you can get away with a low or shorter wall, this may be worth considering. One easy way to do this is to work with diagonal lines rather than following the natural corner of your property.

You can also do your garden in stages. Look at the areas you want to be changed most desperately and do those first. Once the work on them is done, you can think about saving up to do the rest of the garden.

Buying second hand materials is a good way to save on retaining wall costs. With labour being an expensive part of any garden makeover, any parts that you can safely do yourself will also help to reduce costs.

Can I build a DIY retaining wall?

Building a retaining wall can sometimes be a DIY project, but only if the wall is lower than the height specified by your local council. Even then, you should think twice before building a retaining wall, as even a 600mm high retaining wall can collapse and cause injury or damage if it's not installed correctly. Hiring a professional helps to ensure that your retaining wall will stand the test of time.

Interlocking concrete blocks can be easier to install DIY than other options. If the wall is over the height for DIY construction, retaining wall builders can quickly build a wall from interlocking blocks, which require no mortar.

Getting quotes for cheap retaining walls

If built properly, you will have a retaining wall for a long time. Compare quotes from three or more local retaining wall builders on hipages to make sure your project goes to plan.

Think carefully before choosing retaining wall materials. Is having a more expensive retaining wall going to pay off in the long run? A beautiful retaining wall can also boost the price of your home, should you decide to sell.

*Costs and prices in this article are indicative and should only be used as a guide. They also vary locally and are subject to market forces.