The majority of people are shocked at how much a properly built (i.e not liable to collapse within 10yrs) retaining wall costs – primarily due to the earthworks/engineering and labour involved.
In hill areas or where you encounter erosion and unstable landscapes, a quality built retaining wall is essential. Here on the Sunshine Coast a big percentage of our business is repairing and replacing poorly constructed retaining walls. It’s disappointing and at times farcical to witness what some so called providers install for people under the guise of ‘retaining’. And it constitutes an unnecessarily more costly (and potentially dangerous) scenario when not done right first time.
Here in Queensland, engineer’s approval is required for retaining walls over one meter height. Make sure you or your landscaper are aware of the local authority’s regulations prior to starting work. Proper retaining wall design will also include a drainage system, necessary to prevent the build up of waterlogged soil putting pressure behind the wall, which if not accounted for could leave you with a landslide! It’s the failure to provide any or adequate drainage that is the cause of most failures we witness. Therefore, effective retaining wall design needs to consider, the soil profile, soil type, the height of the wall (and footings required to secure it) as well as any load baring from the likes of driveways and nearby buildings, that will increase the forces that the wall has to withstand. Access to the site, material and labour costs are also factored into the final retaining wall design and project cost.
We realize all the above might have made retaining walls sound a little scary. So now you (hopefully) have some appreciation for why getting them built correctly is so important and the factors that go into designing and building them, we’ll move on to the ‘fun stuff’ – like what they look like and what you can do with them. Because, retaining walls are not just for necessity. Yes, if you’re looking to level the contours of a sloped section, to have flat areas for patios and lawns, you’ll need a retaining wall, BUT they in themselves can present a cost-effective and functional feature to your property, adding dimension to your landscaping. There are so many style and cladding options to make your retaining wall a bit more personal and compliment your garden perfectly.
Timber: Timber sleeper retaining walls are cost effective and present attractive additions to a garden or landscape. They also present good flexibility in that they can be easily cut to shape to accommodate different angles or incorporate built in seating for example.
Concrete: Reinforced concrete sleeper walls with metal posts are popular retaining walls due mostly to the fact they are straight forward to build and present the most durable retaining wall solution. They also come in a variety of different colours and patterns/textures e.g timber and stone looks
Block: specially designed retaining wall blocks come in a variety of types and styles and are stacked to achieve the desired height. Offering plenty of options in terms of shaping e.g. curved walls, and finish (wood and slate look for example)
Block & Render: Block and render walls are built with steel reinforced footings and concrete blocks, typically reinforcing with steel bars and core- illed with concrete. We are able to render finish to specification. There are also a wide range of stone cladding available that we can apply to enhance appearance.
Stone: Natural sandstone block retaining walls, are a beautiful value adding feature and present a classic ascetic and solid retaining wall solution.
Gabion: Gabion Retaining Walls consists of a wire mesh structure that hold rocks or stones in place. They present a cost-effective alternative to stone walls and are popular in large scale commercial landscaping but also on a smaller scale in residential settings