What is a Portal Frame?
Every steel building relies on a strong framework to provide structure and stability. In the commercial steel building sector, portal frames are a preferred construction technique, especially for large, open spaces like barns, warehouses, and storage facilities. These two-dimensional structures are known for their rigid joints between columns and rafters, allowing them to act as a single, unified structure while minimising the bending of beams.
If you’ve ever wondered, “What exactly is a portal frame?”, this guide is here to help.
Understanding Portal Frames
Portal frames are designed to create large, open areas without the need for internal columns or support systems. The frame is made up of interconnected columns and rafters, forming a solid structure capable of withstanding heavy loads and harsh external conditions, such as wind and seismic forces.
This widely-used construction technique links vertical supports (columns) to horizontal beams (rafters) with fixed joints. The result? Wide, open floor spaces ideal for agricultural, commercial, and industrial applications.
Key Components of Portal Frames
Portal frames consist of several essential components, each contributing to the overall strength and functionality of the structure:
• Columns: These vertical structures provide support and transfer loads down to the foundation.
• Rafters: Pitched beams that connect the columns, helping distribute loads across the frame.
• Bracing: Diagonal elements that enhance the frame’s stability and prevent lateral movement.
• Purlins: Secondary beams that support the roof covering and transfer weight back to the main frame.
Typically, portal frames are pre-fabricated off-site and then assembled by skilled installers using welding or bolting techniques. Once the framework is erected, cladding and roof coverings are added to protect the building from external elements.
Benefits of Portal Frames
Portal frames are renowned for their stability and versatility in large steel structures. Some of their standout benefits include:
• Ideal for large, open spaces: Whether it’s a warehouse, distribution centre, or barn, portal frames create expansive areas without the need for internal columns.
• Cost-effective: With fewer internal columns required, portal frames reduce material, labour costs, and time on site.
• Flexible and modular: The design can be adapted to different project specifications, offering excellent flexibility for future expansions or adjustments.
• Highly durable: Thanks to their rigid construction, portal frames can withstand natural forces like strong winds and seismic activity, ensuring long-lasting performance.
The Advantages of Steel
Steel has become a go-to material for modern construction projects, and for good reason. Its combination of durability, lightweight properties, and fast installation makes it an outstanding option for any building. Here’s why steel is such a powerhouse material:
• Lightweight and cost-efficient: Steel frames are up to 60% lighter than traditional concrete frames, significantly reducing shipping and construction times while keeping costs down.
• Bespoke design capabilities: Steel allows architects and engineers to create custom designs tailored to a client’s needs. Whether it’s mezzanine levels, open or enclosed bays, roller doors, or ventilation systems, steel frames offer a wealth of design possibilities.
• Sustainability: Steel is one of the most sustainable building materials available. It’s fully recyclable and can be reshaped and reused without any loss of quality, making it an environmentally friendly choice.
• Improved safety on site: Steel is easier to handle compared to materials like concrete or timber, reducing the need for large labour forces and lowering the risk of accidents. Pre-fabricated steel components, made off-site, also contribute to safer working conditions.
Start Your Steel Project with BM Steels
At BM Steels, we specialise in creating robust steel structures that stand the test of time. Whether you’re planning a new warehouse, agricultural building, or storage facility, we’re here to help bring your project to life with high-quality portal frames.
For more information on how our steel framing solutions can work for you, get in touch with our team today for a free, no-obligation estimate. Let BM Steels be your trusted partner in building strong, sustainable, and cost-effective structures.