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What is a Retaining Wall?

There are endless scenarios and imaginations you might have as you start your gardening journey at home. More often than not, in your gardens, you might want to consider containing soil or making it a much-elevated area in your landscape.

You might want to consider having a somewhat raised area in your garden landscape using soil. This is where retaining walls come in to save you. Retaining walls are structures that keep soil where it should be. 

Have you ever walked in on a somewhat elevated space surrounded and protected by brick walls in the lower area? That’s an example of a retaining wall keeping soil in place. A retaining wall’s job is to retain the soil within that might slide down due to gravity, rain, or any circumstance that moves the soil in the area. May it be for aesthetic or functional purposes, a retaining wall is useful if you want to have different elevated soil areas in your gardens.

There are many different materials you can use to construct your retaining walls. Some of the materials you can get creative with are as follows:

  • Concrete
  • Stones
  • Bricks
  • Wood
  • Steel
  • Natural stone
  • Boulders
  • Gabion

As there are many ways to contain that elevated soil space, there are also different kinds of retaining walls for your landscapes depending on function and purpose. Different methods can be used to keep that soil in and make sure it’s safe and sound from moving about, especially when it rains or when plants and shrubs start to grow over it. These are some kinds of retaining walls you can choose from:

Gravity retaining wall

The most common type of retaining wall is a gravity wall wherein the ideal or suitable heights for your elevated earth is up to 3 metres. Gravity keeps the soil in place because the wall is a very big, thick, vertical structure. Some materials that are commonly for this kind of retaining wall is concrete. Another kind of gravity retaining wall is the crib retaining wall which is made up of interlocking box concretes, but has the same structure as the gravity retaining wall.

Cantilever retaining wall

The cantilever retaining wall is a much slimmer option over the gravity wall. A cantilever retaining wall has a flat horizontal base divided into a heel and a toe to lock in place. The vertical wall that is built from the base is perpendicular to keep the soil inside. 

Cantilever retaining walls can be made using reinforced concrete but can sometimes be more difficult to construct because of the base parts and positioning. It can hold up to ideally 6 metres of soil.

Sheet pile retaining wall

For softer kinds of soil and smaller spaces, a sheet pile retaining wall is more preferable for your landscape. It can be made of wood and steel. This happens: about two-thirds of the wood or steel slab is drilled to the ground to keep the slabs up. It is less expensive than a gravity wall or a cantilevered wall. Sheet pile walls are most effective up until 6 metres of soil height.

Anchored retaining wall

An anchored retaining wall is the perfect answer to make your retaining walls a bit stronger and more durable. Anchored retaining walls have cables that hold it together to the soil and to the other opposite wall enclosing the area. This kind of wall is applicable if you plan to have a really slim and slender wall. It isn’t easy to construct and needs to have meticulous planning to construct properly.

Diaphragm retaining wall

For excavated portions of the landscape, a diaphragm retaining wall is best for trenches and keeping soil out of excavated land. Diaphragm retaining walls can are good for deep trenches around an area. It is generally also designed to keep water out and as such, they’re a bit expensive to construct.

Types of Retaining Walls

At Trees Down Under, we understand that maintaining a beautiful, safe outdoor space involves more than just tree-cutting services. When considering landscaping projects, such as constructing retaining walls, choosing the right materials for the job is essential.

For example, should you use timber or concrete sleepers for your retaining wall? Both options have their advantages and disadvantages. To help you make an informed decision, we recommend reading this informative article from Retaining Wall Supplies: Timber or Concrete Sleepers for Your Retaining Wall: Which is Really Better?

This comprehensive guide will provide you with valuable insights to ensure the success of your retaining wall project.


Trees Down Under have been one of Sydney’s best solutions for gardening needs. If you ever need a reliable and tree removal company to handle your landscaping needs, like consultations on your envisioned retaining walls, don’t hesitate to contact us!

Call us at 0475 463 597 or send us an email here: info@treesdownunder.com.au

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