From Steel to GRP — Rethinking Traditional Material Choices
Introduction
For decades, steel has been the default choice for structural components, platforms, walkways, and safety systems across industries. Its strength, availability, and familiarity make it a comfortable specification for engineers, architects, and contractors. Yet familiarity does not always mean it is the best choice for every application. As performance requirements change and sustainability targets tighten, alternative materials are being evaluated more seriously.
Glass Reinforced Plastic (GRP) is one such alternative. It offers a combination of strength, corrosion resistance, safety benefits, and long-term cost savings that directly addresses many of the limitations of steel, particularly in demanding environments. Moving away from a well-established material requires clear answers to common concerns, and GRP provides them.
Strength and Structural Performance
A frequent hesitation about replacing steel is whether GRP can match the required load capacity. Modern GRP pultruded profiles are manufactured to BS EN 13706 standards, delivering structural performance suitable for industrial walkways, access platforms, and guardrail systems. With ultimate tensile strengths in the range of 483 to 1600 MPa, GRP is more than capable of supporting the loads encountered in most access and safety applications.
Durability in Harsh Environments
One of the most recognised weaknesses of steel is corrosion. Even galvanised or coated steel can suffer damage in coastal, industrial, or wet environments, leading to ongoing maintenance and eventual replacement. GRP is inherently resistant to corrosion, UV degradation, and chemical attack. This makes it a strong candidate for marine, water treatment, and chemical processing facilities where steel structures often deteriorate quickly.
Installation and Handling
Steel’s weight can be both a strength and a limitation. In applications where heavy-duty lifting equipment is available, it may present no problem. In more restricted access sites, it can be a major constraint, adding time and cost to installation. GRP is up to 75 percent lighter than steel, allowing sections to be moved and installed manually in many cases. This not only speeds up installation but can also reduce health and safety risks related to heavy lifting.
Safety Around Live Equipment
In facilities with electrical systems, earthing is an essential safety measure for steel structures. This adds both complexity to installation and additional inspection requirements throughout the life of the asset. GRP is non-conductive, meaning it does not require earthing and can be used safely in proximity to live equipment without additional electrical safety measures.
Lifecycle Cost Considerations
Initial cost is often the first comparison point between steel and GRP. While GRP may have a slightly higher purchase price in some cases, the longer-term costs often tell a different story. Steel structures in harsh environments can require repainting or repair every few years, with full replacement potentially required within 20 years. GRP’s corrosion resistance and long service life, often exceeding 50 years, can reduce total cost of ownership by 30 to 50 percent over its lifespan.
Compatibility and Specification
A common concern is whether switching to GRP will require extensive redesign or retraining. GRP structural profiles are available in standard sizes that align with conventional steel sections, allowing integration into existing designs with minimal modification. Fabrication processes for GRP are straightforward and can be completed with standard tools, making the transition from steel both practical and efficient.
Conclusion
Steel will always have its place in construction and infrastructure, but its dominance should not prevent the consideration of better-suited materials for specific applications. GRP offers strength, durability, safety, and lifecycle cost benefits that make it a credible alternative in many scenarios. For engineers, specifiers, and contractors, rethinking material choices could unlock operational, financial, and environmental advantages that traditional options cannot deliver.
