Sandstone entry wall
So what is Gabion & why is it the latest fad in landscaping?
Gabion is a wire basket or wire form, filled with stones and shaped into a fence or retaining wall type structure. Its name comes from its civil history and it is still commonly used in civil works today for soil retention, drainage and erosion control. Gabion fencing is now the latest fad in residential fencing and soil retention solutions and is specified by many building designers and architects for new houses and renovations. For the DIY person it's quite easy to construct and can look fabulous.
How to construct your own Gabion fence or retaining wall
Gabion fences are heavy structures and depending on the height of the fence and site conditions they may need to be specified by a structural engineer. But for ease of reading this article let 's assume your site is flat and the fence is 600mm in height.
Firstly you will need to undertake a bit of research so that your new fence or retaining wall lives up to your expectations. Here are a few points that you need to consider.
Your needs - What do you need your stone fence for? Security, privacy, safety, shading? You will also need to keep in mind that Gabion fencing is easy to climb so it cannot be used around pool areas or to contain children.
Structure type - The term Gabion basket fencing is used for both the standard basket form and the sheet mesh form, used for fencing and retaining walls. The picture below uses a heavy box wire sheeting that has been formed onsite.
Stone choice - What type of stone will best suit your overall development? Any type of stone can be used but remember the larger the stones the more time consuming filling the baskets will be. Larger stones need to be individually placed to get that classic look. Smaller stones can be poured, using a bucket, into the baskets, with very little stone arrangement required. The labour content on this type of fence can be huge and if you are engaging a contractor, Gabion fencing can be expensive.
Fence height - Your fence height will be dictated by your requirements and council restrictions. In many cases council will not allow any street fences to be higher than 900mm off ground level. If your fence is a side or back boundary fence you will probably be allowed to build the structure to 1800mm high. For any fence between 600 and 1800mm high vertical support will need to be factored in and a structural engineer must be engaged.
Services - Fences over 900mm in height can accomodate lighting and plumbing conduits very well. Service installation is easy, but remember that they will need to be roughed-in and secured into the ground and baskets, before your stones are back filled into the baskets and your services can be fitted off. In-Gabion lighting can be spectacular, image a luminating stone fence, ensure the lighting is arranged in place during the process of filling the baskets. In-ground spike lights washed over a Gabion wall can also look amazing.
Let's get started!
Ground preparation - Since we have a block that is totally flat our work is made easier, but you will still need to clear the fence area of vegetation, including grass, stones and tree roots. If your fence is low you will only need to make the ground level before the baskets are aligned and filled. Levelling is easy and can be done using a level and a long piece of timber.
Reinforced concrete strip footings - The footing cut should be about 400mm wide x 400mm deep - check the current Australian Standard for strip footing construction. The concrete footings provide the Gabion fence with a solid base to absorb vertical and lateral loads. Steel reinforcement is then installed horizontally into the footing cuts and at this time steel columns will also need to be inserted well into the footing cut andsecured firmly to the wire basket structure.
Lateral support - If you are using a sheet form fence and the fence height exceeds the fence width, lateral support will no doubt be required. The lateral support prevents the fence from ballooning outwards and also provides bracing to the fence.
Filling the fence - Any stone can be used to fill the baskets but keep in mind that the larger the stone, the more time consuming it will be to fill the baskets if you want an ordered and classic look. Small river stones are one of the easiest fills to work with although ballooning will be more prevalent and extra lateral support maybe required. The order of filling for mesh Gabions will be this - stone fill to 400x400mm in height then install lateral support, stone fill again to 400mm in height and again install lateral support. The installation of all the lateral supports cannot be done in one process due to possible damages to lateral supportand mesh cage.
Engineering - This type of stone filled fence will mostly need to be designed and inspected by a structural engineer and it is also advisable to engage a building designer or an architect to ensure the aesthetic has been well though out.
The fun bit!
Once the filling is complete there comes the fun bit, washing your fence. No I'm not crazy. Once you have spent all that time on your Gabion fence sitting back and looking at your washed down fence is a real buzz. Enjoy your new fence.
Where to find a Gabion Wall expert
Greater Sydney area, Central Coast and Newcastle. Other areas of NSW considered.
Mb. 0411 968 005. Adam McCall is an experienced landscaper and is qualified to design and build walls up to two metres high.
Other areas of Australia: Find a local landscaper.