Which material is best for your retaining wall project?
Precast concrete panels are not just for industrial and commercial construction applications, rather they are a cost and time efficient alternative to traditional retaining wall products. But let’s break down all the options…
Timber had traditionally been the go-to option when it came to retaining wall material. The relatively cheap option was highly resistant to pests and fungi during the time timber was treated with arsenic – however, given the toxicity treated pine is now the only cheap option currently available.
Treated pine may be the least expensive option, but doesn’t possess the longest lifespan; with replacement generally required around the 10-15 year mark at best. However, if you’re looking for a cheap and short-term solution, treated pine may be the way to go.
The primary weakness of this option, is the wood itself, which is subject to rot due to extensive wood to earth contact.
COST: $250-350/sqm supplied only
LIFESPAN: 10-15 years
DESIGN OPTIONS: Moderate
Core-filled concrete blocks, reinforced concrete blocks, besser blocks – are all various names for essentially the use of concrete blocks, reinforced by concrete (and in some cases, steel).
Concrete blocks are widely used in structural landscaping for both residential and commercial applications, however this method is labour intensive given that blocks need to be laid and mortar used between each block. Dependent on the height of the retaining wall, you may need to go a step further and reinforce walls with steel. There are also interlocking options which help streamline the installation process, however this option comes with a hefty price tag.
Whilst there are options for customisation in terms of polished finishes, along with the ability to render and also paint; the opportunity to customise beyond those is limited.
COST: $400 to $680/sqm (reinforced concrete blocks). $550 to $700/sqm (for concrete besser blocks).
LIFESPAN: 50 years
DIFFICULTY: Moderate – Difficult
DESIGN OPTIONS: Moderate
Concrete sleepers have emerged as a popular option for retaining wall applications given they are easier to install than traditional products and allow for a myriad of design options. One common design feature used for both residential and commercial applications is the integration of a woodgrain finish. Concrete sleepers are much like precast panels, however are a more expensive option with a shorter lifespan and more of them are required to fill the same space. The use of many parts instead of one panel results in a lack of strength and higher risk of breakage, however, does assist with drainage requirements.
COST: $320-500/sqm (decorative finishes are more expensive)
LIFESPAN: 60 years
DESIGN OPTIONS: Extensive
The beauty of precast panels is the ability to use them for a variety of applications. Akura’s engineers and draftsman can design and certify the structural capacity of the retaining wall and our state-of-the-art precast plant has the capacity to produce 1,200sqm of panels per week; ensuring short lead times and fast delivery. With precast concrete panels taking only a day to cure, the panels are then ready for distribution to site whereby they can be lifted into the footing; which (dependent on the project size) can take only a matter of hours.
As the manufacturer, Akura has the flexibility to apply a range of architecturally designed finishes to our precast concrete panels, including finishes such as woodgrain, brick and polished along with exposed aggregates and decorative in-lays. Precast concrete panels can also be tinted or painted to suit any colour scheme; thus allowing the retaining wall to become a piece of art; complementing the surroundings with its unique finish.
COST: $150-240sqm (dependent on sizing/thickness, job size and finish) – supply only
LIFESPAN: 50-100 years
DESIGN OPTIONS: Extensive
Retaining Wall FAQ's
If the wall is intended to be over one metre high, an engineer’s certificate and design may be needed, along with Council Approval (depending how close the wall is to a boundary or another building).
There are a large number of materials for the use of retaining wall construction, and the best material relies heavily on where and how it is set to be used.
In terms of longevity, cost efficiency and installation process, precast concrete panels tick all the boxes; lasting upwards of 50-100 years, being a cost effective option and coming in pretty simple when it comes to installation.
Whilst treated pine is probably the cheapest type of retaining wall, this is in short-term instances, given treated pine only has a lifespan of around 10-15 years.
When comparing this to something like precast concrete panels, the long-term lifespan of this material far outweighs the short-term benefit associated with cost.
The cost is dependent on the materials used, area and height that requires retaining along with costs associated with installation; however as a general rule cost per sqm is in the vicinity of $130-700.
USING PRECAST CONCRETE PANELS FOR YOUR RETAINING WALL
For more information on precast concrete panels, their use in retaining wall construction or for an obligation free quote, please contact our Project Consultants.