Last Updated Mar 17, 2017 · Written by Craig Gibson
Retaining walls can be made from a variety of materials, but nothing beats concrete when it comes to strength and durability.
With the new moulded concrete retaining wall systems available today, a concrete retaining wall can not only be built very quickly but it will be durable and easy on the eye. First thing you need to know is how much your concrete retaining wall project is going to cost.
Here's what you need to know.
Retaining walls are used to contain a slope or to form terraces of different levels. There are useful for creating a step in a sloping block can make your yard more user friendly. You can also use a retaining wall or a system of these to segment a garden and create a network of planter boxes. This is a great way to add definition to your backyard, and turn an old boring suburban back yard into something spectacular.
Need a reason why you should consider concrete as a material for your retaining wall?
Don’t listen to us, here is what builder James Mason of Our Build Handyman and Home Improvements had to say, “The great thing about interlocking block retaining walls is the ease of construction, In some cases concrete footings are not necessary and the simple installation method makes it DIY friendly for most homeowners to try their hand at.”
“If you are thinking of rendered masonry, this is a great way to achieve a contemporary look for any garden, be aware that this style of construction will generally involve reinforced concrete footings that an engineer may need to design. With retaining walls it's what is below the surface that counts, making sure adequate subsoil drainage is installed will ensure you will achieve longevity in the look of your wall for years to come.”
Read more: Building a Gabion Retaining Wall
If the height of your wall is taller than 1 metre, assume you will need to employ a structural engineer. Throughout Australia, the services of a structural engineer are required by law for all retaining walls over a metre in height and in some areas the minimum height may be as low as 600mm. If your retaining wall is less than 1.5 metres away from your property line or another building, you will probably need council approval to build it, no matter how high it is. Retaining walls under a metre will generally would not require council approval as they would be classified as a non structural wall.
The height of a retaining wall isn't the only reason why you may need to have your retaining wall designed by a structural engineer, either. Other factors to consider include:
A retaining wall must be built at least 60cm away from an adjoining property line. In other areas it can be 90cm or more
Your retaining wall cannot divert water to an adjoining property.
There are many other considerations as well. Before you do anything, ask your local council for specific information about building retaining walls in your area.
#hiptip: Check with your local council before you build a retaining wall of any height
A number of factors will influence the cost of your retaining wall, specifically:
For a larger retaining wall, there are a number of costs to consider.
You may need council approval and if your retaining wall is going to be over a metre in height, you will have to hire a structural engineer to design and oversee construction of the wall. You may need to buy a more expensive reinforced system and will have to take technical details such as drainage into account. Remember, there's a reason why councils require the services of structural engineers: if a retaining wall collapses, it poses a significant danger to you and your family.
Expect to be quoted based on materials and labour, with materials calculated on a per square metre basis. For a concrete retaining wall expect to pay:
#hiptip: You need to consult a structural engineer if your retaining wall is over one metre in height
For the services of an engineer expect to pay:
Read more: Do I Need an Engineer for My Retaining Wall?
When it comes time to hiring take the time to make sure your tradie is right for your job. Some questions to ask then include:
Get quotes for your concrete retaining wall
A professional retaining wall builder knows how to do the job right and build a retaining wall that will last as long as the concrete blocks themselves last. This will give you a sense of what market rates currently are.
You can also get inspiration for your project in our gallery of retaining wall design ideas.
* All the costs and prices quoted were sourced at the time this article was written. They are indicative, may vary locally, are subject to market forces and should only be used as a guide.