I-bar FRP grating is the premium pultruded pattern in which the bearing bars have an I-shaped cross section rather than a flat or rectangular bar. The I-section places the fibreglass where bending stresses are highest - at the top and bottom flanges - giving the maximum span-to-weight efficiency of any FRP grating profile. That makes I-bar pultruded grating the choice for very long, heavily loaded walkways and bridges where minimising self-weight maximises the span between support beams. Manufactured by Nantong Zeall New Materials Co., Ltd. (ZeAllgrate) since 2004, ISO 9001 certified and exported to more than 45 countries, I-bar grating is the high-performance counterpart to our standard pultruded and molded ranges.
The I-bar profile is also easier to handle than a deep solid rectangular bar of equal stiffness: more of the section is hollow web, so a 75 mm I-bar panel weighs noticeably less than a 75 mm solid bar while delivering comparable bending resistance. This weight saving matters most on elevated structures, rooftop walkways and footbridges where every kilogram of floor adds to the supporting steel and to installation crane time. ZeAllgrate can supply the I-bars with a gritted top flange, black or coloured resin, and matching end plates so long-span FRP bridges arrive as a coordinated, corrosion-proof system.
The I-section maximises bending efficiency: material is concentrated in the tension and compression flanges.
| Parameter | Value |
|---|---|
| Bearing bar profile | Pultruded I-bar (I-section) |
| Typical bar depth | 50 / 75 / 100 mm (custom on request) |
| Flange / web | Wide top and bottom flanges connected by a thinner web |
| Typical opening | approx. 40-50 mm between bars |
| Load direction | Along the I-bars (unidirectional) |
| Resin options | Polyester; vinyl ester for severe corrosion |
| Surface finish | Grit top (standard); smooth available |
| Panel length | up to 6 m bars; custom panels |
I-bar grating is specified where the combination of long span, high load and light self-weight matters most. Typical uses include footbridges and elevated walkways over wide process areas, offshore platform topsides and helideck access, long-span pipe-rack walkways, wastewater treatment tank bridges that must clear wide aeration basins, power-plant and steel-mill access grids, mining and mineral-processing walkways, chemical plant access platforms, and any structure where reducing the weight of the floor reduces the cost of supporting steel. It is also preferred for crane-access walkways and long maintenance corridors where deflection must stay small. The gritted I-bar top provides a secure footing even on long, slightly deflected spans.
Choose I-bar pultruded grating for the longest spans and highest strength-to-weight ratio: the I-section is the most efficient bending profile. Choose a T-bar or rectangular pultruded bar (heavy-duty pultruded grating) where a simpler, deeper bar is adequate or where cost is a concern. Choose molded grating (38mm, 50mm) when loads arrive from both directions or layouts are irregular. Always orient I-bars across the span. Pair with vinyl ester resin for acids and caustics.
ZeAllgrate I-bar grating is manufactured under ISO 9001. Flame spread meets ASTM E84 and pultruded profile production follows relevant FRP industry practice. Section dimensions, bar straightness and resin content are checked on each batch.
Support the I-bars across the span and fix with purpose-made clips at every support; ensure full flange bearing. Cut bars with a fine-tooth saw and seal ends with resin. Do not over-tighten clips, which can crush the pultruded web.
Q: Why is an I-bar better than a flat bar?
A: The I-section concentrates glass in the top and bottom flanges where bending tension and compression are highest, giving much greater stiffness per kilogram than a solid rectangular bar.
Q: How far can I-bar grating span?
A: Further than molded or flat-bar pultruded grating for the same depth; exact spans depend on bar depth, load and deflection limits and should be calculated for your project.
Q: Is I-bar grating bi-directional?
A: No, strength runs along the I-bars only; cross rods tie them together laterally. Orient the bars across the span.
Q: Can it be grit-topped?
A: Yes, the top flange is normally gritted for anti-slip footing in industrial and marine service.
See the pultruded FRP grating product page and heavy-duty pultruded grating overview. Molded alternatives: 38mm, 50mm. Resin: vinyl ester. Applications: construction, steel plants, chemical plants.