In short: Compare cable tray on life-cycle cost, not first price. By material density, steel (about 7,850 kg/m³) is more than four times heavier than FRP (about 1,700–1,800 kg/m³), and aluminum (about 2,700 kg/m³) is about 1.5 times heavier; real tray weight also depends on section and wall thickness. Galvanized life follows zinc thickness and air quality, aluminum loses strength quickly at high temperature, and FRP life follows the resin's fit to the chemicals. Discount future maintenance and replacement to present value, as the NIST method does, and use your own quotes. FIBROVX quotes FRP tray to your route and loads so you can price it fairly.
How this guide fits with our others
This guide is about cost, life and weight. Choosing a material by site condition (chemicals, chlorides, conductivity, grounding) is covered below under What the code says and Site-by-site comparison. For loads and spans, see FRP cable tray load and span selection.
Weight: what the numbers mean
Density figures for the three materials:
- Steel: about 7,850 kg/m³ (Engineering ToolBox).
- Aluminum: about 2,710 kg/m³, and 2,720 kg/m³ for 6061 alloy (Engineering ToolBox).
- FRP: 1.7–1.8 kg/dm³, that is 1,700–1,800 kg/m³, for molded FRP in the FRP grating manufacturer's technical guide. Ask for the value for the section you are offered.
Per cubic meter, steel is about 4.4–4.6 times heavier than FRP, and aluminum about 1.5–1.6 times heavier. That does not mean an FRP tray weighs a quarter of a steel tray. FRP is much less stiff than steel (EN 13706 grade E23 profiles need a modulus of at least 23 GPa, against about 200 GPa, or 29,000 ksi, for steel), so FRP side rails often have thicker walls or deeper sections for the same load and span. Compare the weight per meter of the actual tray from each bid.
Why weight matters on site:
- Lighter sections are easier to lift by hand on platforms, in tunnels and on rooftops.
- Lighter tray adds less dead load to the supports and the structure.
- Fewer lifting aids and less hot work can shorten installation. FRP is cut and drilled without hot work; its cut edges must be sealed with resin.
Service life: what drives it
Galvanized steel
The ABB Cable Tray Technical Guide notes that, in a given environment, galvanized corrosion resistance is a linear function of zinc thickness, and that hot-dip galvanized products more than triple the life of pre-galvanized products. The American Galvanizers Association defines time to first maintenance as 5% rusting of the steel surface. Its long industrial-atmosphere figure (72–73 years) is for structural steel 1/4 in or thicker with at least 3.9 mils of zinc, not for thin tray sheet. Use the AGA Zinc Coating Life Predictor for your zinc thickness and site.
Aluminum
ABB says aluminum is lightweight, naturally corrosion resistant in many environments thanks to its oxide film, and easy to form. Two limits matter for life:
- Heat. ABB's table for AA6063-T6 shows relative strength of about 65% at 149 °C (300 °F) and 6.5% at 204 °C (400 °F). ABB says these figures are for general information only, not design.
- Contact and deposits. ABB warns that copper ions or trace mercury can corrode aluminum, and that oxide-film metals can pit under deposits and in crevices.
FRP
ABB describes fiberglass tray as pultruded with polyester or vinyl ester resin and as having good corrosion resistance in many corrosive environments. Its life depends on matching the resin to the chemicals and temperature, protecting the surface from UV outdoors and sealing cut edges. See UV degradation of FRP and FRP temperature limits by resin type.
Cost: compare on present value
First price is only one line. A fair comparison adds, for each option over the same study period:
- First cost: tray, fittings, covers, supports and hardware.
- Installation: labor, lifting, hot-work permits, access.
- Maintenance: inspection, touch-up of cut edges and coatings, cleaning.
- Replacement: any section that will not last the study period, plus the outage to replace it.
- Residual value at the end of the study period, if any.
The NIST Handbook 135 life-cycle costing manual discounts every future cost to a present value at a stated discount rate. For example, at a 3% real discount rate a single cost in year 15 has a present-value factor of 0.642, and a cost repeated every year for 15 years has a factor of 11.94. Applying the same base date, rate and period to every option keeps the comparison fair. Our FRP vs steel grating 20-year TCO guide works through the method in full.
Typical outcomes
These are patterns, not price claims. Run your own numbers.
- Dry indoor areas. Galvanized steel usually has the lowest life-cycle cost, because the zinc lasts and maintenance is light.
- Mild outdoor or high-temperature runs. Galvanized steel or, away from heat, aluminum often wins; check aluminum's strength at temperature.
- Corrosive areas (chemical, wastewater, cooling tower, coastal splash). FRP often wins because metal tray needs recoating or replacement within the study period. NEC 392.10(D) permits nonmetallic tray in corrosive environments.
- Electrical isolation needed. FRP avoids the cost of tray bonding, since NEC 392.60(A) grounding rules apply to metal tray. Plan a separate grounding conductor where your design needs one.
Getting comparable bids
Ask every supplier for the same items:
- Tray type, width, side height, and weight per meter of the offered section.
- Rated load at your support span, with the deflection basis.
- Material: zinc thickness and process for steel, alloy for aluminum, resin type for FRP.
- Fittings, splices, covers and hardware included.
- Expected maintenance and the basis for any service-life figure.
What the code says
In the US, cable tray installations follow NEC Article 392.
- 392.10(D) permits nonmetallic cable tray in corrosive environments or where the electrical conductivity of the tray is a risk, per ABB's summary of the code.
- 392.60(A): metal cable tray supporting electrical conductors must be grounded per 250.96. Bonding jumpers are needed at expansion joints and some discontinuities.
- Sunlight: cables exposed to direct sunlight must be identified as UV resistant. That applies whatever the tray material.
Nonmetallic tray is built and tested to UL 568 / CSA C22.2 No. 126.2 in North America and to IEC 61537 elsewhere. NEMA FG 1 was rescinded in 2017, per the Cable Tray Institute. FIBROVX does not claim a listing to any of these; tests and documents are confirmed with each quotation.
Site-by-site comparison
| Site condition | Galvanized steel | 316L stainless | FRP |
|---|---|---|---|
| Dry indoor, no chemicals | Usually the economical choice | Rarely needed | Works, rarely needed |
| Coastal air, salt spray | Zinc is used up faster | Better; watch crevices | Good; choose UV-stable resin and surface |
| Acid or caustic fumes | Marked unsuitable for many acids in ABB's guide | Depends on chemical and chlorides | Good when resin suits the chemical |
| Wastewater, H₂S | Check coating life with the AGA predictor | Can pit under deposits | Common choice |
| Voltage isolation, magnetic fields | Conductive, must be grounded | Conductive, must be grounded | Nonconductive, nonmagnetic |
| Sustained high temperature | Good | Good | Limited by resin temperature |
These are screening notes, not a rating. The ABB corrosion guide stresses that trace contaminants, wet/dry cycles and temperature can change results a great deal. Its rule of thumb is that a 30 °C change in temperature can change the corrosion rate by about ten times.
How we customize FRP tray
FIBROVX builds FRP cable trays and FRP cable supports to your route: ladder, perforated or solid-bottom tray, covers, fittings, resin for your chemicals and UV-stable surfaces for outdoor runs. See the cable trays and supports collection and our industries page. We do not publish generic prices or ratings; each load, weight and dimension is confirmed in writing with the quotation.
Need a quote or a drawing check?
FIBROVX manufactures FRP products in our own factory in China and builds every item to order: sizes, resin system, color, molds and OEM branding. Send your application, dimensions or drawing, quantity and destination port.
Request a QuoteWatch: FRP vs Steel vs Aluminum Cable Tray in 27 Seconds
FAQ
How much lighter is FRP cable tray than steel?
By density, steel is about 4.4–4.6 times heavier than FRP. Actual tray weight depends on the section, so compare weight per meter from each bid.
Is FRP cable tray more expensive than galvanized steel?
It can cost more up front. In corrosive areas the life-cycle cost is often lower because metal tray needs maintenance or replacement. Compare on present value with your own quotes.
Is aluminum a good middle option?
It is light and resists many atmospheres, but it loses strength quickly at high temperature and can corrode in contact with copper ions or under deposits.
How long does FRP cable tray last?
That depends on the resin's fit to the chemicals, UV protection and installation. We confirm the basis of any figure with the quotation.
Do you publish prices?
No. FIBROVX is a custom manufacturer, and every tray is quoted to your drawing and loads.
Sources
- A European pultruder, European Standard EN 13706 (E23 minimum modulus 23 GPa)
- American Institute of Steel Construction, steel properties (E = 29,000 ksi): https://www.aisc.org/
- ABB, Cable Tray Technical Guide (aluminum, fiberglass and galvanized properties; hot-dip vs pre-galvanized life; AA6063-T6 relative strength by temperature; deposit, crevice and galvanic corrosion; NEC 392.10(D), 392.60(A)): https://library.e.abb.com/public/3d71fb96ede6403da4863aa740f133c8/Cable_Tray_Technical_Guide_2020_EN_web.pdf
- Engineering ToolBox, Metals and Alloys – Densities (steel 7,850; aluminum 2,712; 6061 2,720 kg/m³): https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html
- An FRP grating manufacturer, Molded FRP Grating Technical Data Guide (density 1.7–1.8 kg/dm³)
- American Galvanizers Association, Time to First Maintenance (5% rusting definition; 72–73 years for structural steel 1/4 in or thicker with 3.9 mils): https://galvanizeit.org/hot-dip-galvanizing/how-long-does-hdg-last/in-the-atmosphere/time-to-first-maintenance
- American Galvanizers Association, The Zinc Coating Life Predictor: https://galvanizeit.org/knowledgebase/article/the-zinc-coating-life-predictor
- NIST Handbook 135 (2025 edition), Life Cycle Costing Manual for the Federal Energy Management Program (present value method; SPV 0.642 and UPV 11.94 at 3% over 15 years): https://nvlpubs.nist.gov/nistpubs/hb/2025/NIST.HB.135e2025.pdf
- NFPA 70, National Electrical Code: https://www.nfpa.org/codes-and-standards/nfpa-70-standard-development/70
- Cable Tray Institute, Codes and Standards (NEC Article 392; UL 568; CSA C22.2 No. 126.2; IEC 61537; NEMA FG 1 rescinded 2017): https://www.cabletrays.org/codes-and-standards/
- IEC 61537:2023, Cable management – Cable tray systems and cable ladder systems: https://webstore.iec.ch/en/publication/31963