Why GRP/FRP Cable Trays Are Replacing Metal in Harsh Environments

Every industrial facility relies on cable trays to keep electrical and communication lines safely routed and easy to access. For decades, metal trays like steel, galvanised steel, and aluminium were the default choice. Today, that default is shifting. As facilities face tougher conditions such as corrosion, chemical exposure, high humidity, and extreme temperatures, many engineers are turning to glass-reinforced plastic (GRP) and fibre-reinforced plastic (FRP) cable trays. Their corrosion resistance, stable performance in harsh environments, and lower maintenance demands are making them a practical alternative to metal, especially in sectors where reliability and long service life are critical. 

Technical Comparison 

Here we delve into the properties, advantages and disadvantages of GRP/FRP vs. metal (steel/aluminium) cable trays. Let's look beyond the hype to the hard facts. 

Material & Basic Properties 

Metal cable trays: Typically carbon steel (hot-dip galvanised or painted), stainless steel (e.g. SS304/316) or aluminium alloys. 

GRP/FRP cable trays: Composite materials-glass fibres embedded in a polymer resin (often vinyl-ester, polyester, or other thermosets) via pultrusion or moulding.

Advantages – GRP/FRP 

Corrosion resistance: GRP/FRP trays are “completely immune to rust and degradation from moisture, chemicals, acids, alkalis and salt-water (saline environments)”. 

Electrical insulation / non-conductivity: Being non-metallic, they reduce risks of stray currents or grounding issues in cable systems. 

Lightweight and ease of installation: GRP/FRP trays weigh significantly less than steel equivalents; one source quotes ~40% faster installation in corrosive areas thanks to their lighter weight and modular design.

Low maintenance & long life in harsh environments: For example, FRP trays can last 25–30 plus years even under corrosive stress, whereas metal trays may degrade in 5-10 years without intensive upkeep. 

Fire retardancy and UV/weather resistance: Many FRP/GRP systems are formulated for fire resistance, UV-stability, and outdoor durability. 

Advantages – Metal 

High structural strength and load-bearing capacity: Steel trays can handle heavier cable loads or long spans more robustly in many standard applications. 

Lower initial cost in non-extreme environments: Metal trays (especially basic galvanised steel) often cost less upfront, making sense in mild indoor settings.

Disadvantages – GRP/FRP 

Higher upfront cost: The composite trays often cost more initially than standard metal trays.

Strength limitations for extremely heavy loads or extreme mechanical abuse: Some sources indicate that FRP’s load capacity may be lower than steel in heavyweight applications.

Specialised joinery/support and compatibility issues: While lighter, proper installation, correct support spacing, compatible fasteners etc are critical to maintain performance. Some engineering care is required. 

Disadvantages – Metal 

Corrosion vulnerability in harsh conditions: Especially in marine, chemical, high humidity or salt-spray climates, even galvanised or stainless steel can suffer degradation, rusting, coating failure, and maintenance burden.

Electrical conductivity & heat transfer concerns: Steel conducts electricity and heat, which may increase risk in fire or fault conditions, or complicate insulation/grounding strategies.

Weight and installation cost: Heavier material means more support infrastructure, more labour, and potentially more downtime during installation or modification

Industry Insights 

Market Trends & Analytics 

• The global GRP cable tray market (for cable trays and ladders) is forecast to grow strongly, with a projected CAGR around 8% + from 2025 to 2033 (e.g., valued at ~US$762.4 million in 2025 according to one report).
• End-use sector “chemical industry” alone accounts for over 25% of FRP cable tray demand, driven by corrosive substances exposure such as acids/alkalis/solvents.
• The Asia-Pacific region is projected to see the fastest growth given rapid industrialisation, offshore wind, renewable energy infrastructure, and harsh outdoor conditions. 

Real-World Application / Case Study 

Consider the project at the PlasChem Industrial Park in Jubail, Saudi Arabia: In this hot, corrosive petrochemical environment the installation replaced metal trays with FRP cable trays. The benefits included elimination of rust concerns, reduced structural load (owing to lighter trays), and improved safety (non-conductive). 

In another general case study, A chemical plant replaced traditional metal cable trays with FRP/GRP trays, resulting in significantly reduced maintenance costs and improved long-term safety.

The total cost of ownership (TCO) is shifting the favour toward composites. Upfront cost may be higher, but installation speed, lower labour, and long-term maintenance savings make GRP/FRP compelling in the right setting. 

In the Gulf, heat, humidity, salt, and sulphur compounds create debilitating conditions for metallic trays; engineers increasingly specify non-metallic systems for new builds and retrofits. 

GRP/FRP cable tray systems excel where the environment is merciless, exposed to chemicals, saltwater, humidity, UV/heat, or where electrical insulation and low maintenance are imperative. Traditional metal trays retain relevance in benign or indoor settings where loads are heavy, cost is constrained and corrosion risk is minimal. 

The key lies in matching the environment and application to the material and system, not defaulting to “metal because that’s what we’ve always used.” From a lifecycle perspective, composites are gaining traction because the sum of installation, maintenance, downtime and replacement often tilts the balance in their favour. 

Looking ahead: As infrastructure grows (renewables, offshore, chemical, water treatment), and as regulatory/sustainability pressures rise, GRP/FRP will increasingly become the default in “harsh” zones. The TCO narrative and documented case studies support this shift. 

For technical decision-makers: pay attention to standard / resin system, load-rating, support spacing, compatibility of fasteners (especially if mixing metal supports with composite trays), fire-rating compliance, and installation best-practice. The change in material impacts design, maintenance planning, safety and total cost. Put simply, GRP/FRP cable trays are becoming the preferred choice in tough, corrosive conditions. The switch away from metal is backed by solid evidence and growing industry experience.