Steel Purlins: When and How to Implement Them Efficiently

The construction industry continually evolves, marrying traditional practices with modern innovations. Amidst the myriad of choices for building materials, steel stands out, especially in the form of purlins. This article offers a guide on when and how to use steel purlins for maximum efficiency and structural integrity.

What Is a Steel Purlin?

Steel purlins are long, horizontal structures typically used to support roofing materials or the outer facade in construction projects. Due to their strength and durability, steel purlins play a pivotal role in providing additional support and stability to buildings. Whether it's a residential home or a large warehouse, the use of purlins is evident across various types of structures.

Purlins come in various forms, classified by their shape, material, and function. Steel purlins are widely used in construction due to their practical advantages. Unlike wood, steel does not rot, resists moisture, and has minimal expansion or contraction in different climates. These properties make steel purlins a reliable choice for maintaining a roof's structural integrity.

Steel purlins are usually made from cold-formed steel, which is produced by rolling and pressing thin sheets of steel into the desired shape. This method results in stronger, more manageable steel compared to hot-formed options. Once formed, the steel is typically galvanized—dipped in molten zinc—to protect it from corrosion. The galvanization process often gives the steel a distinctive crystalized pattern known as a 'spangle.'

In a building's structural framework, purlins serve as secondary supports, working alongside horizontal elements like girts. These components run between the primary framing, similar to cross beams in wooden structures. The secondary framing, including steel purlins, distributed loads onto the primary framing and foundation. It also provides a base for attaching wall cladding and roofing materials.

Learn more about the differences between girts and purlins here.

When to Use Steel Purlins?

Large-Scale Projects: Steel purlins are ideal for larger buildings such as warehouses or industrial units due to their high load-bearing capacity.

Areas with Extreme Weather: In locations that experience heavy snowfall, strong winds, or frequent storms, the robustness of steel purlins ensures the structural safety of the building.

Design Flexibility: Steel purlins are suitable for both traditional and modern architectural designs. Their versatility makes them a top choice for varied projects.

Long-Term Durability: For projects where longevity is paramount, steel purlins, with their resistance to corrosion and wear, are an ideal choice.

How to Use Steel Purlins Efficiently?

Choose the Right Type:

C Purlins: Commonly used because of their adaptable nature.

Z Purlins: Offer better stability due to their unique shape, ideal for larger or more complex structures.

Correct Spacing: The spacing between steel purlins is crucial. It's determined by factors like the weight of the roofing material and expected environmental loads. Proper spacing ensures even weight distribution and structural stability.

Installation

Alignment: Always lay steel purlins perpendicular to the primary rafters or trusses.

Secure Properly: Use suitable fasteners, such as steel bolts or welding, to ensure the purlins are fixed securely.

Safety Measures: When installing, always use protective gear and ensure that the working area is safe, especially when welding or cutting the steel.

Maintenance: While steel purlins are durable, periodic inspections for rust or wear are vital to maintain their structural integrity.

Integration: Once installed, the roofing material or facade can be seamlessly integrated with the purlins. Ensure that the materials used are compatible with steel to prevent unwanted chemical reactions or corrosion.

Benefits of Using Steel Purlins

Strength and Durability: Steel purlins offer superior load-bearing capacity.

Resistance to Elements: Steel can withstand extreme weather conditions, ensuring the safety of the structure.

Cost-Effective: In the long run, the durability and minimal maintenance of steel purlins can lead to cost savings.

Conclusion

Steel purlins are an indispensable component in modern construction. Their strength, durability, and adaptability make them a preferred choice for many architects and builders. Whether you're constructing a large industrial unit or a modern home, understanding when and how to use steel purlins can significantly enhance the structure's efficiency and longevity.

For projects requiring efficient roof support, steel purlins offer a dependable solution that ensures lasting structural integrity. Try StruCalc’s 30 free trial to help calculate purlins in your structural design.