Why GRP Is Preferred Over Steel: The Complete Guide

Glass Reinforced Plastic (GRP) has become the material of choice across construction, industrial, marine, and infrastructure sectors — and for good reason. Stronger than many traditional materials, virtually maintenance-free, and highly versatile, GRP outperforms steel, concrete, and wood in a wide range of applications.

At Lockinex, we supply a comprehensive range of GRP products for industrial, commercial, and infrastructure use. This guide covers everything you need to know about GRP — what it is, why it outperforms steel, where it's used, and how to choose the right product for your application.

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What Is GRP?

GRP, which stands for Glass Reinforced Plastic (also known as GFRP — Glass Fibre Reinforced Polymer), was first developed in the 1930s for use in construction and manufacturing. It is a composite material made from a combination of glass fibres bonded together with a resin — typically Polyester or Vinyl Ester — forming a material that combines the strength of glass with the versatility of plastic.

The result is an exceptionally durable, lightweight, and corrosion-resistant material that has become the preferred alternative to steel, concrete, and wood across a wide range of industries.

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GRP vs Steel: Why GRP Wins

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GRP Resin Types

The resin used in GRP manufacture significantly affects its performance. At Lockinex, we supply GRP products made from Isophthalic resin as standard — a higher-grade resin than the Orthophthalic resin offered by many other suppliers. We also offer Vinyl Ester GRP by special request for the most demanding chemical environments.

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Key Benefits of GRP

Corrosion Resistant GRP does not rust, corrode, or degrade when exposed to chemicals, saltwater, or harsh weather. Unlike steel, it requires no protective coatings, galvanising, or painting — making it ideal for outdoor, marine, and chemical environments.

Non-Conductive GRP is electrically non-conductive, making it the only safe choice for applications near live electrical infrastructure — rail trackside, electrical substations, chemical plants, and offshore platforms. Network Rail and the Office of Rail and Road (ORR) now require non-conductive structures around live tracks.

Slip Resistant The gritted surface of GRP products provides excellent traction even in wet, oily, or icy conditions — significantly reducing the risk of slips, trips, and falls. This is critical for compliance with HSE regulations on workplace safety.

Lightweight GRP is typically 75% lighter than equivalent steel products, reducing installation costs, structural loading, and handling risks on site.

Fire Retardant Lockinex GRP products are fire resistant to BS EN 13501-1:2018 Class B, S1, D0 — one of the highest fire ratings available in the UK, suitable for rail, marine, and industrial applications.

Low Maintenance No painting, galvanising, or protective coating required. Periodic cleaning is all that's needed, significantly reducing lifetime maintenance costs compared to steel.

UV Resistant GRP maintains its structural integrity and appearance under prolonged UV exposure — unlike steel, which degrades without protective coatings.

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Where Is GRP Used?

Industrial & Warehouse

GRP grating and flooring sheets provide safe, slip-resistant walkways and platforms in factories, warehouses, and processing facilities. Non-conductive GRP handrails and guardrails protect personnel in areas with electrical hazards.

Construction

GRP flooring is ideal for construction site walkways and access platforms — lightweight, quick to install, and non-slip even in wet conditions.

Rail Industry

GRP is increasingly specified for rail infrastructure due to its non-conductivity. Network Rail and ORR require non-conductive structures near live tracks. GRP gratings are used for driver walkways, maintenance platforms, embankment steps, and catch pit covers. GRP modular handrails create safe, non-conductive barriers along trackside areas.

Marine & Offshore

Marine environments are among the harshest for materials — saltwater, UV exposure, and heavy use rapidly degrade steel and wood. GRP excels in these conditions:

• Offshore oil platforms — walkways, safety rails, and handrails
• Ships and vessels — decking and protective barriers
• Ports and docks — jetties, loading areas, and access walkways
• Marinas — pontoons and pedestrian access

GRP marine products are saltwater-proof, UV resistant, fire retardant, and require no painting or galvanising — delivering significant lifetime cost savings over steel alternatives.

Chemical Processing

GRP's resistance to a wide range of chemicals makes it the preferred flooring and handrail material in chemical plants and processing facilities. Vinyl Ester GRP is available for the most aggressive chemical environments.

Docks & Ports

Non-slip even when wet, saltwater-resistant, and low maintenance — GRP is the natural choice for dock and port infrastructure where safety and durability are paramount.

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GRP vs Galvanised Steel Key Clamps

For handrail and guardrail applications, the choice between GRP and galvanised steel key clamps depends on your environment:

Choose GRP when your environment involves electrical hazards, saltwater, chemicals, or where non-conductivity is a regulatory requirement.

Choose galvanised steel for standard industrial, warehouse, and construction applications where cost-effectiveness is the priority.

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GRP vs Steel Grating

For most industrial flooring applications, GRP grating outperforms steel on safety, maintenance, and lifetime cost. Steel grating may be preferred where very high point loads are required.

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Our GRP Product Range

At Lockinex, we stock a comprehensive range of GRP products:

• GRP Mesh Gratings — Isophthalic resin, fire resistant to BS EN 13501-1:2018 Class B, S1, D0. Available in a variety of colours, sizes, and apertures for flooring, walkways, platforms, and drainage covers
• GRP Anti-Slip Flat Sheets — non-slip surface for landings, walkways, and ramps
• GRP Modular Handrail System — fully non-conductive key clamp and tube handrailing, installed at railway sites and chemical plants across the UK
• GRP Non-Slip Stair Tread Covers — anti-slip covers and nosings for steel stair treads, providing high visibility and grip
• GRP Pultruded Profiles — I-beams, angles, and structural sections for bespoke fabrication
• GRP Ladder Rung Covers — for access ladder kits used in working at height applications

All products are available in standard sizes or can be cut to length. Download our Non-Slip Technical Brochure for full technical specifications.

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Need Help Specifying GRP for Your Project?

Not sure which GRP product is right for your application? Contact our team at sales@lockinex.com or call 01323 737 626 — we're here to help you find the safest, most cost-effective solution for your requirements.