Heavy-duty FRP grating is specified where standard panels cannot carry the load — vehicle access, machinery platforms, cooling towers and oil-and-gas walkways. This guide covers how heavy-duty fiberglass grating is rated, when to choose molded versus pultruded, and how to read a load/span table.

What is heavy-duty FRP grating?

Heavy-duty FRP grating means panels engineered for higher load capacity and longer unsupported spans than standard walkway grating. They use thicker panels (typically 38–50mm molded) or deep-section pultruded I-bar profiles that resist deflection under concentrated and uniform loads. For loads that would crush standard grating, heavy-duty composite panels keep the corrosion resistance, light weight and non-conductive safety of FRP.

Molded vs pultruded for heavy loads

Molded heavy-duty grating — usually 38mm or 50mm with a dense mesh — offers high strength in two directions and is the economical choice for most platforms and trench covers. Pultruded I-bar grating carries higher load per metre and reaches longer spans, making it the standard for heavy vehicle walkways, cooling tower decks and large industrial platforms. Use pultruded where load direction is known and long unsupported spans are required.

Load capacity and deflection

Load capacity is expressed as a uniformly distributed load (UDL) or a concentrated point load (PL) that a panel can carry at an acceptable deflection — usually L/100 or L/200 of the span. The deflection limit matters as much as the breaking load: many projects specify deflection, not ultimate strength. ZeAllgrate publishes load/span data for each panel depth and mesh so you can size the grating to your actual span and traffic.

Reading a load/span table

A load/span table shows, for a given panel thickness and mesh opening, the maximum safe span for each load class. To use it: 1) determine your design load (personnel ≈ 100–150kg point load; light vehicle ≈ 500kg wheel load; heavy vehicle up to several tonnes), 2) choose an acceptable deflection (L/100 for walkways, L/200 for platforms), 3) read the maximum span, and 4) space support beams at or below that span. ZeAllgrate can provide span tables and a load calculator for your project.

Applications and specification

Heavy-duty FRP grating is used in chemical plants, wastewater treatment, offshore and oil-and-gas facilities, power-plant cooling towers, rooftop solar walkways and dock decks. Specify the load class, span, surface (grit-top or concave), resin system and whether you need fire-retardant or UV-stabilised resin. ZeAllgrate manufactures heavy-duty molded and pultruded grating to your engineering requirements.