How much does a retaining wall cost?

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The quick answer is $266 per square metre, just multiply the total length by total height to get your result. This is a very close estimate for a treated pine timber system including agg pipe, posts, labour and materials. 

Call 6 Axis on 0404014848 to confirm quote. 

The latest and most versatile systems currently on the market in Australia that is price conscious and durable is the concrete sleepers in steel posts, this can be priced at $488 per square metre. 

For concrete block locking systems expect to pay $600 per square metre based on easy access and aggregate fill for hollow blocks. 

All the above mentioned prices are our prices supplied, installed and delivered rates in and around Sydney Suburbs. 

Do you want to maximise your outdoor area?

A retaining wall may be the solution to create an area that is more practical on the feet and easy on the eyes. With a range of materials and styles available, you can turn your backyard or frontyard into a space that suits your lifestyle.

Types of retaining walls

Some of the retaining wall materials you have to choose from include:

  • Timber: Treated pine are most typically used. They last between 6 -10 years if installed correctly. We recommend 75mm thick sleepers for heights over 600mm which can drive up the cost marginally. 
  • Concrete Blocks: with suitable footing that can last the life of the masonry, a correct installation of interlocking blocks for a retaining wall can last 20 years or more. Also ideal for tight access installations.
  • Concrete Sleepers: in Galvanised Steel H Posts: One of the most versatile systems currently available which makes for a fast durable installation.    
  • Natural stone: boulders make great retaining walls. Expect it to be more than a quick weekend project, though, because part of the art of stacking boulders is finding the perfect fit. 

The way we work is by removing all the old material (if any) and levelling the ground to suit your desired finish. This will give you a nice clean slate to work with and get the measurements precise. 

Your home’s value can be boosted by adding properly built retaining walls or by upgrading or replacing the current retaining walls on your property. The main elements to consider when building a retaining wall are materials and quality of installation. A professionally installed wall will withstand the elements and last for decades. You may be wondering what are the different types of retaining walls? The three main types of retaining walls are concrete, and masonry or stone. The materials you choose will depend on the location of the wall, the aesthetic qualities you prefer, and how long you expect the wall to last.

A retaining wall is used to contain soil and hold it in place in areas where a slope is present. Retaining walls can be used to set off patio and entertainment areas or create paths in residential backyards. Also they can be used to restrain soil in order to form usable roads. Building a retaining wall on your property is no small job, and you want the wall—whether made of concrete, or masonry—to last for as many years as possible. Here are some facts on retaining walls to help you make the best decision for your needs.

Concrete and Masonry Walls

Poured concrete is the strongest and most durable choice for retaining walls. It may also be carved and formed to look like mortared stone depending on your taste. Poured concrete walls are the only type of retaining wall that aren’t built to be battered (leaned back) against the earth, which is useful if you are short on space.

Interlocking concrete blocks are another alternative—and one which is an easy choice for DIYers. Though made from concrete, the blocks usually have a rough face for a quarried look. They are manufactured to easily fit together without the use of mortar. Masonry retaining walls can be built either with or without mortar and will likely need a mason for proper installation. If they are built properly, they will last upwards of forty years.

Choosing Retaining wall materials

When choosing the materials for your new retaining wall, always choose the best quality material you can afford — the better the materials, the longer the wall will last (and the safer it will be as well). Remember that a retaining wall is meant to hold back tons of soil, so be sure to only use top-quality material. If your retaining wall will be more than 1 metre high, you are also obligated to use an engineer and you may also need a permit. Aesthetics will play a big role in your choice of material.

The parts of a Retaining Wall

Each retaining-wall material has its needs in terms of space, labour, and installation expertise. The requirements of each type of retaining wall usually include aggregate, drainage pipe, geotech fabric, protective membrane and then of course the system itself. 

Masonry Retaining Walls

For a masonry retaining wall, it’s best to get a professional mason to install the wall. The footing must be placed below the frost line and should be made from rebar reinforced concrete (a steel bar or mesh of steel wires is embedded within the concrete to strengthen it). Weep holes (small holes that help the water to drain water away from the wall) must also be utilised every 1.6metres. Mortar-free walls, however, only need a crushed-stone footing rather than a reinforced-concrete footing. A batter of 60mm per 300mm of wall should be added.

Poured Concrete Retaining Walls

A professional brick layer must construct the Besser block retaining wall and then block filled with  Like the masonry wall, the poured concrete wall also needs a reinforced concrete footing and weep holes every 60mm per 300mm. However, poured concrete retaining walls do not need a batter.

Interlocking Concrete Block Retaining Walls

A retaining wall constructed of interlocking concrete blocks requires a simple crushed-stone footing. Heavy-duty mesh anchors every other course against the ground, and it also has a batter of 60mm per 300mm of wall.

SandStone Boulder Retaining Wall

Stunning, grande, elegant, natural and heavy duty – Large Sandstone blocks are also an upcoming trend ideal for solid solutions that can be an abstract feature in your house and can potentially add thousands of dollars in value. Each block is approximately saw cut into 1 metre x 0.6m x 0.6m blocks and placed using an excavator without damaging them to create a wall feature.

When does a Retaining Wall Needs to be Replaced?

Although retaining walls can last for decades, there does come a time when they need to be replaced. If you see any of the following signs, it’s time to start planning a replacement wall as the building material has been compromised;

  • Leaning — Usually caused by tree roots, poor drainage, or a failed footing
  • Cracking — Small cracks may be filled in, but cracks more than a quarter inch wide and deep and more than 2 feet long are signs of structural damage
  • Sagging — Sagging is a sign that the footing has failed at a specific spot. A professional may be able to rebuild the affected section of the wall, but depending on the extent of the failure, the whole wall may need to be replaced
  • Bulging — Bulging is a sign of a buildup of water pressure behind the wall, or a lack of anchoring in the case of interlocking blocks. Careful excavation may save the wall, but it may need to be rebuilt.

6 Axis – The Retaining Wall Experts in Sydney… 

We pride ourselves on being a few steps ahead of the competition because we take extra precautions to ensure our work is above Australian standards for a longer lasting finished product. Any staff or contractor that works for us has to work to our strict standards, no shortcuts, ever! 

Contact 6 Axis when you’re considering any project that involves any building and excavation works including patios, driveways, retaining walls and total landscaping.

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