FRP Grating Load Capacity

FRP Grating Load Capacity

How to read load and deflection tables, and how to choose a mesh for your span.

How FRP Grating Load Data Works

A load table is how you check whether a grating panel suits a span before anything is built. Every table has three ingredients: the span between supports, the load applied, and the mid-span deflection that results.

Two load cases are published. Linear load (kg/m) treats the load as running along a line, such as a pipe crossing the panel or a concentrated foot load.

Uniform load (kg/m²) spreads the load evenly across the whole panel, such as a crowd of people or evenly stored material. The tables below give the mid-span deflection in millimetres for each combination of span and load.

The tables also list a limit load: the ultimate capacity of the panel. Working loads stay well below it by a safety factor, and in most projects the deflection limit decides the mesh long before the limit load is reached.

Deflection limits are set by the project specification or the applicable standard, so always check the number your project allows.

19*19H30 Linear Load Table

Span (mm) 75 kg/m 150 kg/m 300 kg/m 450 kg/m 750 kg/m 1500 kg/m Limit load (kg/m)
300 <0.25 <0.25 0.25 0.51 0.76 1.52 9923
450 0.25 0.51 1.02 1.52 2.54 3.92 4827
600 0.51 1.27 2.29 3.56 5.84 7.38 4112
750 1.27 2.54 4.83 7.37 12.4 16.0 3174
900 2.27 4.54 9.08 13.6 18.7 22.1 2637

Mid-span deflection in mm for molded 19*19H30 grating under linear load. The 38*38H30 mesh publishes its own tables with limit loads of 9923, 4828, 4112, 3174 and 2637 kg/m at spans of 300 to 900 mm.

19*19H30 Uniform Load Table

Span (mm) 350 kg/m² 500 kg/m² 750 kg/m² 1000 kg/m² 1500 kg/m² 2500 kg/m²
300 0.29 0.48 0.57 0.75 1.15 1.82
450 0.78 1.19 1.81 2.47 3.54 4.95
600 1.76 2.66 4.28 5.56 8.41 13.2
750 3.48 5.12 8.21 11.0 16.4 —
900 5.89 8.81 14.2 18.9 — —

Mid-span deflection in mm under uniform load (kg/m²). A dash means the combination is not rated in the published table.

Heavy-Duty Mesh Data

When spans or loads run past the standard meshes, the heavier molded panels carry the duty. 50*50H50 (78% open area, 23.7 kg/m²) is rated to a 1200 mm span:

50*50H50 limit load 300 mm 600 mm 900 mm 1200 mm
Linear (kg/m) 21727 11713 7780 5834

The 38*152H38 mesh (67% open area, 15.92 kg/m²) has load-bearing bars running lengthwise in the direction of the span, giving it a very high limit load across its rated range:

38*152H38 limit load 300 mm 450 mm 600 mm 750 mm 900 mm 1050 mm 1200 mm
Linear (kg/m) 12628 9946 8233 7040 6146 5439 5141
Uniform (kg/m²) 41358 26962 21716 18446 13420 10180 8418

For very heavy loads on closely spaced supports, the 38*38H50 mesh at 42 kg/m² is the heaviest molded panel in the range. See the high-load molded gratings page for the full heavy-duty family.

How to Use These Tables

  • Match the load case: line loads such as pipes or concentrated foot loads read from the linear table; evenly spread loads read from the uniform table.
  • Read the deflection, not just the rating: every cell is a mid-span deflection in millimetres for that span and load combination.
  • Compare with your deflection limit: many walkway projects work to a limit around span/100, but always use the value your project specification sets.
  • Interpolate carefully: values between the listed spans and loads can be interpolated, or ask us for the exact figure.
  • Watch the span line: if the mesh you like runs out of deflection allowance, the next mesh up - or pultruded grating - is the usual answer.

For how molded and pultruded grating carry load differently, see the molded vs pultruded comparison. For mesh sizes, panel dimensions and resin systems, see the FRP grating specifications guide.

Our Grating Range

Molded grating with published load data: 19*19H30 (40% open area, 19.1 kg/m²), 38*38H30 (68%, 14.6 kg/m²),

50*50H50 (78%, 23.7 kg/m²) and 38*152H38 with lengthwise load bars (67%, 15.92 kg/m²).

For spans beyond the molded tables, pultruded grating carries higher loads along the load bars - see the high-load pultruded gratings page. Browse the full FRP grating range.

Send us the span, the working load and the deflection limit and we will return the matching table values and a mesh recommendation - contact us at admin@greenlogy.cn.

Frequently Asked Questions

How do I read an FRP grating load table?

Find your span in the left column, then follow the row to the load level you need. The cell gives the mid-span deflection in millimetres. Compare that deflection against the limit set by your project, and pick the mesh and thickness that stays inside it.

What is the difference between linear load and uniform load?

Linear load (kg/m) runs along a line, for example a pipe resting across the grating or a concentrated foot load. Uniform load (kg/m²) spreads over the whole panel, for example a crowd of people or stored materials. The tables publish deflection values separately for each case.

What does limit load mean in the tables?

Limit load is the ultimate load the panel can carry before failure, as listed in the published table. It is not a working load. Working loads are kept well below it by a safety factor, and the deflection limit usually decides the choice long before the limit load is reached.

What is the maximum span for molded FRP grating?

The standard meshes cover spans up to 900 mm in the load tables, and the heavy 50*50H50 mesh is rated up to 1200 mm. For longer spans, pultruded grating carries much higher loads along the load bars and is the usual choice.

Where can I get load tables for a specific mesh?

Send us the mesh, the span and the working load and we will return the matching table values. Published data is available for the 19*19H30, 38*38H30, 50*50H50 and 38*152H38 meshes, and we can advise on intermediate sizes.