Gabions are evolving

As environmentally engineered structures, gabions come in many forms, making them a highly flexible solution for projects ranging from retaining walls to river erosion countermeasures. However, there’s also a growing demand for their application in building projects, and as an architectural element, says Louis Cheyne, managing director, Gabion Baskets. By Alastair Currie

Recently celebrating its 15th anniversary, Gabion Baskets has gained extensive experience as a specialist manufacturer of gabion systems. Traditionally, these entail the fabrication of flexible double-twisted, hexagonal mesh products. Alongside this has been a steady diversification into welded mesh systems designed for non-structural applications. Prime examples include building cladding and perimeter walling.

“Our strength as a business has been forged by the close relationships developed over the years with consulting engineers and contractors specialising in the multifaceted field of environmental engineering,” says Cheyne. “Many are now pushing the boundaries of conventional design to execute amazing projects.”

In addition to providing design and product recommendations, Gabion Baskets provides on-site installation training for contractors and their subcontractors.

“There’s an increasing demand for this, especially when providing support for new SMME subcontractors, plus community training forming part of Expanded Public Works Programmes,” Cheyne continues, adding that part of this support includes assisting SMMEs to correctly price jobs when drawing up a bill of quantities.

LANDSCAPING

SECUNDA RIVER WALL

Secunda river wall elevation

Secunda river wall

A recent example of close collaboration and teamwork is on a complex river stabilisation project bordering a new housing development currently under construction in Secunda, Mpumalanga. The main contractor is Roos & Rosslee Construction. The contractor approached Gabion Baskets for input in March 2021. In response,

Using square welded mesh, Gabion Baskets’ installation team recently constructed a simple wall layout that adds a key aesthetic element for a suburban home. The design includes a flowerbed section and access steps

CLADDING

Anchoring welded mesh gabion panels that will form part of a wall cladding system

Gabion Baskets completed a detailed site assessment, design proposal and costings. The approximate length of the wall is 300 m.

“We suggested using a river wall on rock solution, as there was bedrock at the river base,” Cheyne explains. The proposal was to establish a concrete base to level out the foundation for the gabions to rest on. Thereafter, construction would start with a 1 m high river retaining wall, moving up to 3 m in height, at 0.5 m stepped intervals every 20 m. PVC-coated, double-twisted hexagonal Class A galvanised wire was also recommended for the fabrication of the gabion baskets.

“PVC coating, with an indicative design life of 60 years, is the preferred route for any river installation, especially for submerged sections that will be subject to potential corrosion and scouring,” says Cheyne.

Gabion Baskets provided on-site training for a week to ensure that the contractor’s installation team was proficient in the lacing, bracing, and packing of the correct quality and sized rock within the gabions.

Building and architecture

Experienced design engineers and contractors understand the key difference between flexible hexagonal and square welded mesh. The former is designed to flex, particularly in a riverine environment. As the name implies, though, welded mesh is rigid. However, both are now being used for applications outside pure engineering. Examples in terms of flexible mesh include landscaping and boundary walls.

“However, it’s important to emphasise that welded mesh is purpose designed for building and architectural applications, where its flat form is ideal for design elements like cladding,” Cheyne points out.

As part of its research and development programme, Gabion Baskets continues to experiment with welded mesh materials as it explores new market opportunities. This recently included a residential project in Gauteng, where Gabion Baskets’ team designed and built a low walling system that includes steps and flowerbeds. This relatively low-cost project was completed over a weekend and adds significant aesthetic appeal.

Gabion Baskets sees huge scope for this type of design, whether for affordable or luxury housing. It’s also a perfect opportunity for SMME landscapers to enter the market, as well as an employment generator for communities employed on human settlements projects when supported by formal training programmes. Alongside residential, another major growth market for welded mesh is in the architectural cladding space. Recent projects where Gabion Baskets has supplied its product include retail and commercial developments.

As with any cladding system, factoring in the height and weight is key, as is adequately anchoring the welded mesh rock-filled panels. In addition to external cladding, welded mesh walls are also proving very popular for internal layouts, further extending their versatility.

The initial river section prior to gabion wall construction The wall nearing completion in late July 2021 Filling welded mesh gabion panels. Rock selection and colour can vary depending on the architectural design, while non-rock fill materials can also be used. The panel type specified has a 50 mm x 50 mm aperture, with 3.00 mm Class A galvanised steel wire selected

New Cape Town facility

Forming part of its expansion strategy, Gabion Baskets recently opened a new factory in Elsies River, Cape Town, to service the Western Cape region. In addition to its Johannesburg factory, Gabion Baskets also has a KwaZulu-Natal facility, based in Pinetown. Across South Africa and Southern Africa, the market is further serviced by appointed distributors.

“One of our first customer engagements at the Elsies River factory was an order from a local wine farmer, who also sent one of their construction teams for an in-depth training programme,” adds Cheyne.

“Based on our experience to date, this is a further example of the growing interest from inside and outside the construction industry about how gabions can add value, in terms of both form and function,” Cheyne concludes.