You’ve probably seen them in all kinds of places: wire baskets of stones piled up against slopes and rivers, or neatly dividing green spaces. Gabion walls have seen a resurgence in use and popularity lately, but they are far from new. Used by military and structural engineers for thousands of years, including on the banks of the River Nile, they form a time-tested and dependable structure that has countless benefits and uses.
The word gabion comes from the Italian gabbione which literally translates as “big cage”, and this is essentially what they are – cage-like enclosures filled with inorganic material like stone, brick or broken concrete. Also known as gabion cages, their main use in structural engineering has been for protecting shorelines, river banks and slopes from erosion, and they're either laid at angles in “mattress” form or, more commonly, stacked incrementally like bricks.
Nowadays though, they are used for all kinds of other practical reasons, as well as purely aesthetic reasons. More and more gardens, urban spaces, towns and land re-development projects are transforming the way gabion baskets can be used and are employing them to build walls, pillars, benches and base structures, as well as to separate and divide areas, reinforce earth walls, and as a buffer for water features. The baskets themselves can come in a range of different sizes to suit all kinds of needs and designs, and are constructed using tough, galvanised wire mesh, usually of a 3mm thickness.
One of the reasons gabion walls are so popular with gardeners and landscapers is because anyone can build and place their own baskets and use them how they want to – they’re the DIY way to build walls and other similar structures in your own space. All it takes is a plan and some elbow grease.
Images by Catherine Stewart.
Take a look at Catherine Stewart’s post which explains every step she took to build a gabion wall in her front garden, including step-by-step pictures to show you how everything went together. As Catherine explains, she was able to fill hers with on-site sandstone which they broke up themselves, but that doesn’t mean you need an abundance of available stone on your doorstep in order to fill up your basket. Gabion stone can be sourced easily and in a range of sizes and colours, meaning you can tailor your design to fit your environment, making them an attractive and customisable addition to your space.
One of the core reasons that gabion walls have stood the test of time – ever since they were used on the banks of the River Nile – was that they are extremely flexible and durable. Under great stress, a gabion basket will deform, buckle or compress very slightly, rather than break. This is a functional feature that prevents loss of structural integrity and ultimately makes it stronger over the course of time. Additionally, not being fixed to the ground (like a normal wall would be) means there will be an allowance for all the small ground movements which happen naturally.
Though it might not look it, the wire mesh that makes up the basket or cage is very strong under tension and acts as a reinforcement of the overall structure, rather than just a container. And due to silt and vegetation collecting in between the filling over time, they actually become even stronger with age, and form a naturally permanent structure. Many people have taken advantage of this fact to use gabion baskets as a base for tables and benches.
The nature of the way gabion baskets are made means there is space in between the stone filling. This allows both air and water to pass through, which allows the whole structure to breathe. On the other hand, concrete structures can build up hydrostatic pressure due to their impermeability, and this can compromise their structural integrity.
Made from wire mesh, gabion baskets are less expensive than most construction materials like concrete, and can be put together easily by anyone, avoiding the need to buy heavy concrete or to mix it yourself. Filling like stone or broken concrete can usually be sourced locally and at a much lower cost. At Mainland Aggregates, we supply a wide selection of gabion stones to fill gabion baskets. Our range includes white gabion cobbles, blue pennant gabion stone, dove grey gabion stone and Cambrian green gabion stone.
Labour costs can also be all but eliminated, as almost anyone can construct a gabion basket structure without the need to hire people to do it. The only exception here is if you’re building over a metre in height – then we recommend consulting a professional in order to keep it safe.
One of the key benefits of gabion walls over traditional walls is that you don’t need a conventional foundation – a compacted layer of filling like crushed rock is often all that is required to give the baskets a firm footing. You may think that translates to the base not being firmly planted in the ground, but this isn’t the case. As long as you’ve flattened and prepared the ground to put the wall on, the fill at the bottom of the basket will settle into the ground directly, providing frictional strength which keeps the baskets in place and prevents the structure from being dragged away by a river or stream.
The principal benefit and practical use for gabion walls, as mentioned above, is to reduce or prevent erosion. This works by absorbing the force of flowing water, as the energy is dissipated by the stone fill, thus protecting areas under risk of erosion. For this reason, they’re used to bolster river banks and shorelines that are under threat of erosion. If you have a pond or a stream, or your garden backs onto a river, a gabion wall be a great practical way to protect the land.
A major reason that gabion baskets and walls are popular is that, despite being man-made structures, they still look natural and can match a space to its local terrain through the use of local filler materials. Baskets of many different sizes and shapes can be used, including curved baskets which form a bend or circle when put together, and filling of all kinds of colours, textures and sizes can be used inside them.
When local material is used for filling, transportation costs and the associated fuel consumption are almost eliminated, meaning putting together a gabion wall takes much less toll on the environment than a traditional concrete wall. Also, since the filling is making use of materials that already exist, there is no extra demand on the creation of concrete or other such materials. Thanks to their strength and permeability, gabion walls are also extremely long-lasting, durable and sustainable, so won’t need replacing or repairing as often as other walls.
As long as you’ve done some research and have what you need, you can put together your own gabion wall within one day. All it takes is to fasten the baskets together, prepare the ground where they will lie, and fill with your chosen filling. One key trick is to pick your flattest and best-looking pieces of stone or rock for the sides that will be seen most frequently – many people line the edges with the best pieces and fill the centre with cheaper filling like broken concrete, as well as saving any rare right-angled pieces for the corners. If you’re building over a metre in height or planning to build on top of the wall or baskets, then you should consult a structural engineer, but for other uses, they really can be done all by yourself.
Unlike a concrete wall or structure, gabion baskets aren’t fixed to the ground, and can therefore be moved or taken down with relative simplicity, to accommodate a changing environment or just aesthetic preference. This can give you the flexibility to try out a garden or landscape design, and if you don’t like the look of it or how it works practically, you can take apart the baskets and move them around however you like, as many times as you like. Just be prepared for a bit of heavy lifting!