Using cellular beams has enabled steel distributor Macsteel to ensure not only aesthetic appeal but also structural integrity and durability. This will be demonstrated by three key projects that will be entries in the 2025 and 2026 Southern African Institute of Steel Construction (SAISC) Steel Awards.

Cellular beams, a variation of the I-section beams known for superior bending performance, are particularly suited to spanning longer distances without increasing weight, says Macsteel engineering manager Axel Kayoka.

Owing to these properties, cellular beams were used for the Dornier Wine Estate’s winery and tasting area upgrade, in Stellenbosch, in the Western Cape. The project involved the refurbishment of an outdated external seating space into a modern, “visually striking” wine tasting environment, he explains.

Macsteel collaborated with engineering consultancy DVH Consulting Engineers to evaluate and select the most structurally efficient and aesthetically-appropriate beam profile for the application. This partnership ensured the design intent was achieved without compromising on performance or timelines.

“Macsteel was a natural choice for this project, owing to our proven capability in designing and manufacturing cellular beams, including curved cellular sections,” adds Kayoka.

The client required a design that was lightweight, durable, low-maintenance and visually appealing. Cellular beams met these requirements by providing structural integrity, architectural expression and the ability to span about 14 m while maintaining a lightweight section.

They also seamlessly integrated into the existing architecture and industrial aesthetic.

“The external tasting area sits adjacent to a glass façade that looks into the winery, and the cellular beams reinforce this visual language externally,” says Kayoka.

A key challenge of the project was achieving the tight curvature – a radius of about 16.5 m – required for the beams. This created complexities in the manufacturing and assembly stages, which Macsteel’s production team managed through close coordination across all processes, ensuring the curved cellular beams met the required specifications.

Despite the technical difficulty, production stayed on track to prevent delays to the fabrication programme, which was managed by structural steelwork fabricator Triomf Staalwerke.

Curved cellular beams were also integral in independent school St Charles College’s swimming pool complex project, in Pietermaritzburg, KwaZulu-Natal.



The facility’s architectural design integrates steel and concrete to deliver a structure that is functional and visually distinctive.

The design brief called for “an iconic structure with a sweeping, curved roof to reflect the ambition of the project”, which aims to nurture future generations of swimmers and water polo players.

As a result, curved cellular beams were selected to complement the architectural vision while providing the necessary load-bearing capacity and structural efficiency outlined in the detailed specifications.

The curved cellular beams allow for long, uninterrupted spans across the pool area without the need for internal columns. This design approach is essential for large aquatic facilities where clear sightlines and unobstructed space are key, Kayoka notes.

In addition to the beams, the project used Macsteel’s Novotexi 440 concealed-fix roof sheeting system, which offers “superior” wind resistance, longevity and clean visual appearance.

The roof sheeting was installed using a sky-forming method, further enhancing construction speed and safety. 

Macsteel, in collaboration with structural steel specialists Cousins Steel International, supplied the curved cellular beams, while the latter managed the fabrication and erection of the entire structural steelwork package.

Macsteel also contributed to the construction of a new geospatial science laboratory at the North-West University’s Vanderbijlpark Campus.

“A major design consideration was the client’s requirement for large, unobstructed floor spans to facilitate open-plan teaching and laboratory areas.”

Given the structural load imposed by concrete floors, steel proved to be the most suitable material, Kayoka explains. 



He notes that using structural steel, particularly cellular beams, significantly enhanced the project.

From a cost perspective, the steel-framed skeleton minimised foundation requirements, owing to its lighter weight, compared with conventional solutions. Construction timelines were also reduced. 

Architecturally, the steel system allowed for greater design flexibility. 

“Overall, steel contributed to a robust, efficient and aesthetically adaptable structure,” Kayoka concludes.