FRP Grating Load Calculator

Greenlogy TEC Engineering Tools · Grating Load Greenlogy TEC · Grating Load

Molded & Pultruded FRP Grating Load Calculator

Estimate deflection for molded and pultruded fiberglass grating at your span, using the concentrated and uniform load tables published on each product page. Filter by family, select several types and compare them side by side with colour-coded safety results.

Molded + pultruded Product-page data Real-time calculation Cross-family comparison Colour-coded safety
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Select grating types

Switch family, then search or tick types; select across families to compare.

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Load case

Span, load type and load value.

mm
kN/m²

Method and data notes

The calculator uses the deflection tables published on each molded and pultruded product page: concentrated-load tables are given as kg/m line loads and uniform-load tables as kg/m². Inputs are converted at 1 kN = 101.97 kgf, then bilinearly interpolated across span and load.

A concentrated load is entered as a total load P (kN) and divided by the loaded width b (m) to obtain the line load P/b (kN/m) used by the product table. Uniform loads are entered directly in kN/m².

Loads below the table minimum are scaled linearly; spans below the table minimum are evaluated at the minimum span. Loads or spans outside the table, or blank cells in the source table, produce no deflection result.

Safety: deflection at or below the allowable value (L/100 by default) is safe; above it is caution; above 1.5 times it is unsafe. Where an ultimate load is published, a safety factor of 2.0 is applied: load × 2 ≥ ultimate is caution, and load ≥ ultimate is unsafe. The pultruded HL series publishes no ultimate-load column, so those types are assessed on deflection only.

Some pultruded uniform-load tables contain corrected cells or omit the ultimate-load column; the relevant note appears under data notes when that type is selected.

Results are indicative values derived from published tables. Long-term creep, dynamic loads, temperature, chemical exposure, support conditions and installation method are not included. Final designs should be verified by a qualified engineer.

Standards and references

The load selection, calculation method and safety assessment on this page refer to the following standards. They apply to different markets and product types; this tool supports preliminary selection and does not claim full compliance with any of them.

Products and materials

  • GB/T 31539-2015 Pultruded Profiles of Fiber Reinforced Polymer Composites for Structural Use — classification, specifications, mechanical performance requirements and test methods for pultruded FRP structural profiles; used to check the profile properties behind pultruded grating load tables.
  • ANSI/ACMA/FGMC FG01-17 FRP Composites Grating Manual for Pultruded and Molded Grating and Stair Treads (2nd Edition, 2019; current designation FG01-17-2025) — load tables, standard specifications and code of standard practice for grating and stair treads; because FRP has a relatively low modulus, grating design is normally governed by deflection (serviceability).

Design basis and loads

  • GB 50608-2020 Technical Standard for Engineering Application of Fiber Reinforced Polymer Composites — design values and ultimate- and serviceability-limit-state checks for FRP members; the main Chinese national standard for structural FRP design.
  • GB 50009-2012 Load Code for the Design of Building Structures — characteristic floor live loads, maintenance loads and load combinations; used to establish design loads for grating platforms.
  • GB 50017-2017 Standard for Design of Steel Structures — deflection limits and calculation rules for flexural members; used as a reference where no FRP-specific limit is given.

Parameters used on this page

  • Data source: concentrated, uniform and ultimate loads for each type are taken from the load tables published on the corresponding niteck.com product page; source values are transcribed without alteration.
  • Unit conversion: product tables are in kgf; inputs are converted at 1 kN = 101.97 kgf.
  • Allowable deflection: L/100 by default, with L/200, L/300 or a custom value; the governing limit should come from the project specification or design standard.
  • Safety assessment: deflection ≤ allowable is safe, above is caution, above 1.5× is unsafe; where an ultimate load is published, a 2.0 safety factor is also checked.

Standards are revised from time to time; the editions and limits adopted for a project are those named in its contract or design documents. Results are short-term, linear-elastic reference values and exclude long-term creep, dynamic loads, temperature, chemical exposure and support conditions. Final design should be verified by a qualified engineer.

Signed-in visitors can download PDFs of these standards from the reference library: Open the reference library

FAQ · Calculation and selection

Frequently asked questions about grating load calculation

How does the calculator work?

It uses the concentrated-load (kg/m) and uniform-load (kg/m2) deflection tables published on each product page, converts your input at 1 kN = 101.97 kgf, and interpolates bilinearly across span and load. If the span or load falls outside the published table, the calculator reports it as out of range instead of extrapolating.

Which load types and units can I enter?

Uniform loads are entered in kN/m2. A concentrated load is entered as a total load in kN and divided by the loaded width to obtain the line load used by the product table. Span is entered in millimetres, and the allowable deflection can be set to L/100, L/200, L/300 or a custom value.

What do the result colours mean?

Green means the deflection is within the allowable limit. Amber means it exceeds that limit, or that the check against the published ultimate load with a safety factor of 2.0 is close. Red means the deflection is more than 1.5 times the limit, or the load reaches the published ultimate load.

Which grating types are covered?

Every published molded and pultruded FRP grating type. I-50125 and I-60125 are not calculated because their product pages publish no load table.

Can I use the result for construction drawings?

The result is a short-term, linear-elastic estimate for preliminary selection, not a construction document. It excludes long-term creep, dynamic loads, temperature, chemical exposure and support conditions. Final design should be verified by a qualified engineer against the applicable standards, including GB/T 31539-2015, ANSI/ACMA/FGMC FG01-17 and GB 50608-2020.

How do I get a quote or sizing advice?

Sign in, select the types and run the calculation, then use the Request a quote button. The selected types, span, load and results are attached to your enquiry automatically, and our engineering team replies with a recommendation and a quote.