Molded FRP Grating Load Capacity by Span

The table below gives typical uniformly distributed loads (UDL), in kN/m², that our molded FRP grating panels can support at the stated clear span, using a standard deflection limit and a conventional safety factor. Values are indicative for engineering comparison only — final design must be confirmed by the project structural engineer against site conditions.

Unit: kN/m² uniformly distributed load, simply supported clear span. Resin: standard orthophthalic (IS) unless otherwise specified.

Pultruded FRP Grating Load Capacity by Span

Pultruded I-bar grating carries heavier loads over longer spans than molded panels. The two heavy-duty pultruded series below are used for industrial platforms, truck-access walkways and mezzanines where molded grating cannot meet the span requirement.

Unit: kN/m² UDL, simply supported clear span. Pultruded panels available up to 1220 × 6096 mm (4 × 20 ft).

How to Read the Load–Span Table

Span. The span is the clear distance between the two supporting structures (steel angles, concrete ledges or FRP supports). Do not measure the overall panel length — use the uncovered, unsupported length between bearing points.

Uniform load vs point load. The table above assumes a uniformly distributed load spread over the panel. A wheel, forklift pallet or drum creates a concentrated (point or line) load that the table does not directly cover. For vehicle or rolling loads, move up one grade or contact our engineering team for a point-load check.

Safety factor and engineer of record. The published ranges already include a conventional safety factor. They are intended for preliminary sizing and procurement comparison. The project structural engineer remains responsible for the final design, connection design and any local code requirements.

Four-Step Grating Selection Workflow

Step 1 — Fix the span. Measure the clear distance between supports. This single number eliminates most models immediately: short spans (≤ 800 mm) can use molded grating; longer spans (> 1500 mm) usually require pultruded I-bar.

Step 2 — Fix the load. Identify the design UDL from the project specification (walkway, equipment platform, truck route, forklift aisle). Match it against the table at your span, and pick a model whose lower bound still exceeds the design load.

Step 3 — Fix the traffic type. Pedestrian walkways need only the Light or Medium grade. Hand-cart or trolley traffic moves you to Standard. Forklift, pallet jack or vehicle access requires the Heavy molded series or pultruded I-bar.

Step 4 — Fix the environment (resin). Choose orthophthalic (IS) for general industrial and mild chemical exposure; fire-retardant (IF) where flame-spread certification is required; vinyl ester (VE) for strong acid, alkali or marine immersion. See the specification index and standards & compliance pages for detail.

Deflection Control: Why It Matters

Strength alone is not enough — a panel that does not break but visibly bounces underfoot is unacceptable. As a general rule of thumb, ordinary pedestrian walkways use a deflection limit around L/100 (span divided by 100), while platforms carrying machinery, vehicles or dynamic loads use the stricter L/200 limit. Our load–span ranges are published against these conventional deflection targets; if your project specifies a tighter limit, move up one thickness grade rather than accepting deflection drift.

Why FRP Load Capacity Differs from Steel

If you are used to selecting steel bar grating, the numbers on this page will look unfamiliar at first. FRP is anisotropic: molded panels carry load in two directions, while pultruded I-bar panels carry load mainly along the deeper bars. FRP also deflects more elastically than steel at the same section, which is why the deflection limit — not the ultimate strength — usually governs the chosen thickness. The kN/m² ranges above already incorporate this deflection-based sizing, so you do not need to apply a second factor on top.

FRP also does not rust, which means the published values do not degrade over time the way steel corrosion margins do. In corrosive plants, wastewater treatment and coastal applications, vinyl ester (VE) grating retains its load capacity for decades where steel would require galvanizing, painting or stainless upgrades.

One practical implication: when you compare FRP quotes with steel bar grating quotes, do not only compare the per-square-metre price. Count the support beams, the clips, the corrosion protection over 20 years, and the installation hours — FRP panels are lighter and faster to fix, which often closes the gap on total installed cost even when the panel price is higher.

Grating Grade Guide: Light to Heavy Duty

Frequently Asked Questions

Need a load check for a specific project? Request a Quote with your span, design load and environment, and our engineering team will confirm the recommended model. See also the full specification index and FRP grating panels overview.