The Strength and Versatility of Steel Structures for Large-Span Buildings

Large-span buildings are made to provide vast and open indoor spaces unobstructed by columns or load-bearing walls. Which begs the question: what holds up these architectural feats?

Steel is the solid choice for long-span buildings like exhibition halls, warehouses, hangars and bulk storage facilities – in fact, any buildings spanning over 20 metres.

Using steel for long-span structures isn’t new. 19th-century bridges, train sheds, market halls and structures like the Galerie des Machines (1889) in Paris had steel at their core.

What’s changed thanks to technological advancements in steel fabrication, is the way that large-span buildings are designed, produced and assembled to be bigger, stronger, and more cost-effective.

This article discusses the strength and versatility of steel structures for large-span buildings.

What Makes a Large-Span Steel Structure?

Large-span steel structures are a type of building with roofs spanning more than 20 metres. What you will notice about these expansive structures, aside from their sheer scale, is that there are few or no central column supports.

Large-span buildings pose unique challenges for architects and engineers. The ambition for large, open spaces means fewer supports as well as more pressure on the building materials used.

Steel’s special blend of properties makes it the best material for long-span buildings. Thanks to the very nature of long-span construction, steel beams, purlins, trusses, bracing and panels must be engineered, fabricated and installed with precision and care to uphold their integrity and that of the structure.

The Inherent Properties of Steel

Steel offers a combination of strength, versatility, and durability that few other materials can match. Its high strength-to-weight ratio allows for the creation of lightweight yet robust structures, making it particularly suited for long-span applications. Unlike materials such as concrete, steel’s flexibility under load means it can absorb more stress while adapting to movement. This reduces the risk of cracks and other damage.

Technological Advancements: Enhancing Steel’s Performance

Several developments have improved the performance, sustainability, and cost-effectiveness of steel structures. Computer-aided design (CAD) and building information modelling (BIM) allow engineers to optimise the use of steel, creating designs that minimise waste while maximising space and structural integrity. With these tools, intricate and efficient steel frameworks can be designed to carry the loads of long-span buildings safely.

Advancements in Steel Fabrication: Improving Project Efficiencies

Steel structures can be prefabricated off-site in controlled environments, ensuring high precision, and allowing for more efficient on-site assembly and quicker construction timeframes.

This approach also decreases labour costs and mitigates on-site safety risks. These efficiencies make steel a superior material in terms of performance and an economically sound choice for large-scale, long-span projects.

Specialists in steel fabrication for south and sub-Saharan Africa, B&T Steel’s end-to-end, turnkey approach  saves time and reduces complexities and costs throughout the project lifecycle.

Long-span Steel Structure Trends: B&T Steel at the Forefront

As architects and engineers push the boundaries of design, the benefits of steel continue to be reaped in long-span buildings.

B&T offers a range of solutions for truss and portal frame design, employing various strategies to achieve optimal results. This includes identifying the most efficient combination of purlin design and main frame economies. By adjusting main frame centres and selecting the most suitable design methodology, B&T ensures tailored solutions for different main frame configurations, such as lattice trusses, propped portal frames, tied portals, or mansard frames.

Aware that clients often aim to minimise the number of internal supports, B&T specialises in providing the most economical and effective design options to meet these requirements.

Shoprite Riverfields

One of B&T Steel’s recent (2024) landmark projects is Shoprite Riverfields, a mega development spanning over 85 000 square metres of warehouse and office space in Pomona, Gauteng. The facility, serving as a distribution hub for Shoprite, is a gigantic 2031 tonnes – a long-span building in its truest of forms.

Transpharm Warehouse

The 425-tonne Transpharm Warehouse in Louwlardia is another of B&T Steel’s projects, built using steel framing and sheeting materials.