FRP Grating Load & Span Tables
How to Read These Load Tables
All values transcribed verbatim from manufacturer catalogs. Static, ambient-temperature conditions unless noted.
Safety Factor
Molded grating: Max Recommended Load = 5:1 factor of safety on Ultimate Capacity. Pultruded grating: 2:1 F.S. HLC vehicle wheel loads: F.S. 2.5 based on 0.25" max deflection.
Deflection Limit
Pedestrian walkway: deflection limited to the lesser of L/120 or 3/8" (ZeAllgrate). Pultruded comfort: lesser of 3/8" or L/125; firmer: lesser of 1/4" or L/200.
Live Load Basis
Walking / pedestrian uniform live load typically 50–65 psf; concentrated load 250 lb; dead load 3.75 lb/ft². Covered (integral) grating: apply 0.5 multiplier to load values.
Impact / Dynamic
Static ambient values shown. For impact or dynamic loading, use 1/2 of the tabulated values (HLC and pultruded notes).
Test Standard
Molded: ANSI FRP Composites Grating Manual (pultruded and molded grating and stair treads). Pultruded: proposed ZeAllgrate/ACMA standard; per ASCE Structural Plastics Design Manual.
Reading Cells
Every cell shows "Max Recommended / Ultimate" in the stated units (psf uniform; lb/ft width line load). "—" = not listed in the source table for that configuration.
Industry reference — Max Recommended / Ultimate (psf)
Columns = clear span. Values per Industry reference molded catalog p.9.
| Style (depth × mesh) | 12 in | 18 in | 24 in | 30 in | 36 in | 48 in | 60 in |
|---|---|---|---|---|---|---|---|
| 5/8" 1"×4" rect | 1540 / 8130 | 680 / 3410 | 380 / 1920 | 380 / 1920 | — | — | — |
| 3/4" 1"×4" rect | 1770 / 8880 | 600 / 3610 | 330 / 2030 | 330 / 2030 | — | — | — |
| 3/4" 1-1/2" sq | 1350 / 7720 | 780 / 2660 | 250 / 1500 | 250 / 1500 | — | — | — |
| 3/4" Micro 3/4"×3/4" | — | 440 / 3940 | 440 / 2220 | 440 / 2220 | 220 / 1100 | — | — |
| 3/4" 3/4"×4" rect | — | 1240 / 6200 | 700 / 3500 | 700 / 3500 | 140 / 720 | — | — |
| 1" 1"×4" rect | 1420 / 7120 | 950 / 4750 | 530 / 2670 | 530 / 2670 | 110 / 870 | — | — |
| 1" 1-1/2" sq | 2140 / 10700 | 630 / 2290 | 350 / 1780 | 350 / 1780 | 170 / 580 | — | — |
| 1" 2" sq | — | 450 / 3170 | 250 / 1280 | 250 / 1280 | — | — | — |
| 1" 3/4"×4" (Ecograte62) | 2800 / 14040 | — | — | — | — | — | — |
| 1-1/4" 1-1/2" sq | 1110 / 6660 | 740 / 4440 | 250 / 1280 | 250 / 1280 | 140 / 870 | — | — |
| 1-1/4" 2" sq | 1020 / 5140 | — | 440 / 2660 | 440 / 2660 | — | — | — |
| 1-1/2"* 1-1/2" sq | 3200 / 19240 | 1420 / 7100 | 800 / 4000 | 800 / 4000 | 260 / 1700 | 200 / 1000 | — |
| 2" 2" sq | 3840 / 16000 | 1850 / 9280 | 1040 / 5220 | 1040 / 5220 | 340 / 1300 | 260 / 1300 | 160 / 830 |
Note: 1-1/2"* also covers Micro-Mesh 1-1/2" deep × 3/4" top mesh, 4'×12' panel. Per-cell deflection values are tabulated in the source PDF p.9. Source: Industry reference Molded Grating Catalog, p.9.
Max Recommended / Ultimate (psf)
Heavy-load molded grating for equipment decks and vehicle areas.
| HLC Style | 12 in | 18 in | 24 in | 30 in | 36 in | 42 in |
|---|---|---|---|---|---|---|
| 1-1/2" HLC (1"×2" rect) | 28000 / 78000 | 12400 / 31000 | 6800 / 17000 | 4300 / 14500 | 3000 / 10000 | 2200 / 5500 |
| 2" HLC (1"×2" rect) | 31200 / 70000 | 14500 / 36200 | 9000 / 22500 | 5800 / 10700 | 4000 / 7500 | 2900 / 7200 |
Static ambient only; impact/dynamic = 1/2 values; max deflection 0.25" normal (L/500 may be code-required). Source: Industry reference Molded Grating Catalog, p.13.
Max Recommended / Ultimate (lb per ft of width)
Line loads such as equipment feet, rail posts or wheel tracks distributed along a bar.
| Style (depth × mesh) | 12 in | 18 in | 24 in | 30 in | 36 in | 48 in | 60 in |
|---|---|---|---|---|---|---|---|
| 5/8" 1"×4" | 770 / 3860 | 380 / 1920 | 300 / 1530 | 250 / 1270 | — | — | — |
| 3/4" 1"×4" | 500 / 3000 | 330 / 2030 | 270 / 1620 | 220 / 1350 | — | — | — |
| 3/4" 1-1/2" sq | 880 / 4440 | 250 / 1500 | 200 / 1200 | 160 / 1000 | — | — | — |
| 3/4" Micro | — | 440 / 2220 | 350 / 1770 | 460 / 2340 | 400 / 2000 | — | — |
| 3/4" 3/4"×4" | — | 700 / 3510 | 560 / 2800 | 290 / 1480 | 250 / 1260 | — | — |
| 1" 1"×4" | 670 / 3560 | 530 / 2670 | 420 / 2140 | 350 / 1780 | 300 / 1520 | — | — |
| 1" 1-1/2" sq | 1400 / 7020 | 350 / 1780 | 280 / 1420 | 230 / 1180 | 200 / 1010 | — | — |
| 1" 2" sq | 510 / 2570 | 250 / 1280 | 200 / 1020 | 170 / 850 | — | — | — |
| 1-1/4" 1-1/2" sq | 1600 / 8000 | 800 / 4000 | 350 / 2130 | 290 / 1770 | — | — | — |
| 1-1/4" 2" sq | — | — | — | — | 250 / 1520 | — | — |
| 1-1/2"* 1-1/2" sq | 1070 / 6660 | 460 / 2760 | 640 / 3200 | 530 / 2660 | 450 / 2280 | def.-lim.* | — |
| 2" 2" sq | 1920 / 9620 | 1040 / 5220 | 830 / 4180 | 690 / 3480 | 590 / 2980 | 460 / 2320 | 350 / 2090 |
*1-1/2" at 48 in is deflection-limited (0.15" at 500 lb) in the source. Source: Industry reference Molded Grating Catalog, p.11.
Wheel load = 1/2 axle + 30% impact; 0.25" max deflection; F.S. 2.5
Parallel span = bars across traffic; perpendicular span = bars along traffic.
| Load Condition | Wheel Load (lb) | Tire Patch | Parallel Span | Perpendicular Span | Grating |
|---|---|---|---|---|---|
| AASHTO H-20 truck (32000 lb axle, dual) | 20,800 | 20" + 4" | 1'-2" | 1'-5" | 1-1/2" / 2" HLC |
| Automobile (5000 lb, 2200 lb drive) | 2,200 | 8" + 4" | 2'-2" | 2'-8" | 1-1/2" / 2" HLC |
| 5-ton forklift (14400 lb vehicle) | 13,480 | 11" + 4" | 1'-1" | 1'-5" | 1-1/2" / 2" HLC |
| 3-ton forklift (9800 lb vehicle) | 8,730 | 7" + 4" | 1'-0" | 1'-4" | 1-1/2" / 2" HLC |
| 1-ton forklift (4200 lb vehicle) | 3,425 | 4" + 4" | 1'-7" | 2'-1" | 1-1/2" / 2" HLC |
AASHTO per LRFD Bridge Design Specifications, 2nd Ed. Source: Industry reference Molded Grating Catalog, p.12.
Recommended Max Load (kg/m²)
Industry reference molded grating — clear span in metres. Apparent EI per m width ranges 0.03–0.19 ×10⁹ N·cm².
| Thickness × Mesh | 0.30 m | 0.46 m | 0.61 m | 0.76 m | 0.91 m | 1.07 m | 1.22 m | 1.37 m | 1.52 m |
|---|---|---|---|---|---|---|---|---|---|
| 25.4 mm · 38.1 sq | 8788.4 | 3710.6 | 2001.8 | 1249.9 | 878.8 | — | — | — | — |
| 25.4 mm · 25.4×101.6 rect | 9569.6 | 4638.3 | 2607.2 | 1640.5 | 1152.2 | — | — | — | — |
| 38.1 mm · 38.1 sq | 18162.6 | 9276.6 | 5810.1 | 3710.6 | 2392.4 | 1611.2 | 1074.1 | 771.4 | — |
| 38.1 mm · Mini-Mesh | 18162.6 | 9276.6 | 5810.1 | 3710.6 | 2392.4 | 1611.2 | 1074.1 | 771.4 | — |
| 50.8 mm · 50.8 sq | 20896.8 | 11717.8 | 7079.5 | 4394.2 | 2929.5 | 2148.3 | 1660.0 | 1269.4 | 1025.3 |
Source: Industry reference ZeAllgrate Molded Fiberglass Grating — Metric Brochure, p.5.
ZeAll Pultruded — Max Recommended / Ultimate (psf)
Six profiles across spans 12"–72". Values per Industry reference ZeAll Pultruded load tables p.6.
| Profile | 12 in | 18 in | 24 in | 30 in | 36 in | 42 in | 48 in | 54 in | 60 in | 66 in | 72 in |
|---|---|---|---|---|---|---|---|---|---|---|---|
| I4010 | 5350 / 10700 | 3390 / 6780 | 2540 / 5080 | 2060 / 4120 | 1760 / 3520 | 1430 / 2860 | 1080 / 2160 | 850 / 1700 | 690 / 1380 | 570 / 1140 | — |
| I6010 | 3570 / 7140 | 2260 / 4520 | 1690 / 3380 | 1370 / 2740 | 1180 / 2360 | 950 / 1900 | 720 / 1440 | 570 / 1140 | 460 / 920 | — | — |
| I4015 | 11430 / 22860 | 7370 / 14740 | 4790 / 9580 | 4420 / 8840 | 3690 / 7380 | 2760 / 5520 | 2110 / 4220 | 1670 / 3340 | 1350 / 2700 | 1120 / 2240 | 940 / 1880 |
| I6015 | 7620 / 15240 | 4910 / 9820 | 3190 / 6380 | 2950 / 5900 | 2460 / 4920 | 1840 / 3680 | 1410 / 2820 | 1110 / 2220 | 900 / 1800 | 740 / 1480 | 630 / 1260 |
| T3320 | 10080 / 20160 | 6720 / 13440 | 3960 / 7920 | 3460 / 6920 | 2880 / 5760 | 2470 / 4940 | 2160 / 4320 | 1680 / 3360 | 1360 / 2720 | 1120 / 2240 | 950 / 1900 |
| T5020 | 7560 / 15120 | 5040 / 10080 | 2970 / 5940 | 2590 / 5180 | 2160 / 4320 | 1850 / 3700 | 1620 / 3240 | 1280 / 2560 | 1040 / 2080 | 860 / 1720 | 720 / 1440 |
Walking loads typically 50–65 psf. Static ambient only; impact/dynamic = 1/2 values. Source: Industry reference ZeAll Pultruded Industrial Grating Load Tables, p.6.
ZeAll Pultruded — Max Recommended / Ultimate (lb per ft of width)
Bearing-bar direction carries the line load. Orient bars across the span.
| Profile | 12 in | 18 in | 24 in | 30 in | 36 in | 42 in | 48 in | 54 in | 60 in | 66 in | 72 in |
|---|---|---|---|---|---|---|---|---|---|---|---|
| I4010 | 5350 / 10700 | 5080 / 10160 | 4260 / 8520 | 3450 / 6900 | 2950 / 5900 | 2500 / 5000 | 2160 / 4320 | 1920 / 3840 | 1730 / 3460 | 1570 / 3140 | 1440 / 2880 |
| I6010 | 3570 / 7140 | 3390 / 6780 | 2840 / 5680 | 2300 / 4600 | 1970 / 3940 | 1670 / 3340 | 1440 / 2880 | 1280 / 2560 | 1150 / 2300 | 1050 / 2100 | 960 / 1920 |
| I4015 | 11430 / 22860 | 11060 / 22120 | 7310 / 14620 | 6750 / 13500 | 5630 / 11260 | 4820 / 9640 | 4220 / 8440 | 3750 / 7500 | 3380 / 6760 | 3070 / 6140 | 2810 / 5620 |
| I6015 | 7620 / 15240 | 7370 / 14740 | 4880 / 9760 | 4500 / 9000 | 3750 / 7500 | 3220 / 6440 | 2810 / 5620 | 2500 / 5000 | 2250 / 4500 | 2050 / 4100 | 1880 / 3760 |
| T3320 | 10080 / 20160 | 10080 / 20160 | 7920 / 15840 | 6930 / 13860 | 5760 / 11520 | 4950 / 9900 | 4330 / 8660 | 3780 / 7560 | 3400 / 6800 | 3090 / 6180 | 2830 / 5660 |
| T5020 | 7560 / 15120 | 7560 / 15120 | 5940 / 11880 | 5200 / 10400 | 4320 / 8640 | 3710 / 7420 | 3250 / 6500 | 2890 / 5780 | 2600 / 5200 | 2360 / 4720 | 2170 / 4340 |
Source: Industry reference ZeAll Pultruded Industrial Grating Load Tables, p.7.
ZeAll Pultruded profiles — per ft of width
A = area (in²), I = moment of inertia (in⁴), S = section modulus (in³); EI average (lb-in²), valid for spans > 24 in.
| Profile | Depth | Bars/ft | Open Area | Bar Centers | Wt (lb/ft²) | A (in²) | I (in⁴) | S (in³) | Avg EI (lb-in²) |
|---|---|---|---|---|---|---|---|---|---|
| I4010 | 1" | 12 | 40% | 1" | 3.41 | 2.64 | 0.33 | S = 0.63 | 1,700,000 |
| I6010 | 1" | 8 | 60% | 1-1/2" | 2.62 | 3.96 | 0.50 | S = 0.95 | 2,500,000 |
| I4015 | 1-1/2" | 12 | 40% | 1" | 4.13 | 3.20 | 0.94 | S = 1.20 | 4,600,000 |
| I6015 | 1-1/2" | 8 | 60% | 1-1/2" | 2.83 | 4.80 | 1.41 | S = 1.80 | 7,000,000 |
| T3320 | 2" | 8 | 33% | 1-1/2" | 4.00 | 3.20 | 1.68 | St 1.96 / Sb 1.47 | 7,600,000 |
| T5020 | 2" | 6 | 50% | 2" | 3.10 | 4.28 | 2.24 | St 2.61 / Sb 1.96 | 9,200,000 |
Tie bars 6" (152 mm) flush-top. I4010 and T3320 marked ADA Compliant. I-bar config (1", 1-1/2") for most industrial/pedestrian use; T-bar config (2") for wider spans / lower deflection. Source: ZeAll Pultruded, p.5.
HR = highly recommended · R = recommended · A = acceptable · NR = not recommended
Rating matrix from the ZeAll Pultruded design guide.
| Criterion | Molded | Pultruded | Note |
|---|---|---|---|
| Corrosion resistance | HR | HR / R | All systems rated HR/R |
| Bi-directional span | HR | NR | Molded square mesh carries load both ways |
| Single-direction span | A | R | Pultruded bearing bars along the span |
| Ease of installation | A | HR | Pultruded panels cut and clip faster |
| Custom panel sizes | R | NR | Molded molds to near-custom dimensions |
Source: Industry reference ZeAll Pultruded Industrial Grating Load Tables, p.18.
All load-table values are transcribed from the following manufacturer documents.
- Industry reference Fiberglass Molded Grating & Products Catalog (Part No. 885105-05/19-2, ©2019) — molded uniform/line load, HLC, wheel loads.
- Industry reference ZeAllgrate Molded Fiberglass Grating — Metric Brochure (ST1122, ©2022) — metric kg/m² tables.
- Industry reference Guidelines for the Engineer & Designer (Part No. 884305-9/18) — pedestrian design criteria, deflection limits.
- Industry reference ZeAll Pultruded Industrial Grating — Load Tables — pultruded load tables, section matrix, selection guidance. PDF
Final design must be confirmed against certified load/span charts for your exact panel, resin and surface. ZeAllgrate supplies load test reports and material certificates with every shipment.
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