Product specification

1" Thick Molded Fiberglass Grating, 1-1/2" Square Mesh

Updated Oct 17, 2026

Strongrate's 1 inch fiberglass grating is a 1" (25 mm) deep molded panel with a 1-1/2" square mesh, at 2.5 lb/ft² (12.3 kg/m²) and 68% open area per its catalog. Use it for walkways, platforms and flooring where the 1" load table meets your span. The isophthalic model is DNV-listed (TAF0000191 Rev. 1), ASTM E84-19a flame spread index 10.

Specifications: 1" deep, 1-1/2" square mesh

Depth: 1" (25 mm)Inch sizes are North American nominals of the metric certificate designation.
Mesh: 1-1/2" × 1-1/2" (38 × 38 mm), squareInch sizes are North American nominals of the metric certificate designation.
DNV certificate designation: 38×38×25 mmInch sizes are North American nominals of the metric certificate designation.
Resin (DNV-listed model): Isophthalic polyester
ASTM E84-19a flame spread index: 10Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to this model only.
ASTM E84-19a smoke-developed index: 55Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to this model only.
Structural fire integrity: L0 per ASTM F3059-15As stated on the certificate; acceptance for a given location is case by case.
Glass content: 30–35% by total weight (all molded grating)

Strongrate catalog data: 1" deep molded grating, 1-1/2" square mesh

Mesh	Depth	Bar width (as printed)	Weight	Open area
1-1/2" × 1-1/2" (38 × 38 mm)¹	1" (25 mm)¹	1/4" / 3/16" (6.5 / 5.0 mm)¹	2.5 lb/ft² (12.3 kg/m²)¹	68%¹

As printed in Strongrate’s 2023 product catalog; confirmed in your quote and submittal drawings. The catalog prints two bar widths per depth without saying which is the top and which the bottom of the bar.

Notes

1Values as printed in the factory catalog (2023).

What panel sizes are available?

Strongrate's catalog lists 5 ft × 13.12 ft (1524 × 4000 mm); 4 ft × 12 ft (1220 × 3660 mm); 4 ft × 8 ft (1220 × 2440 mm); 3 ft × 10 ft (921 × 3050 mm) for the 1" deep, 1-1/2" square mesh. Send your layout or drawings with the quote request. Sizes and weights of every product are compared on fiberglass grating sizes, weight and open area.

How much load can 1 inch fiberglass grating support?

Read the deflection at your clear span in the catalog tables below, for uniform and concentrated loads at ambient temperature. Halve the loads for impact, and keep pedestrian deflection to the lesser of 3/8" (10 mm) or span/125, as the catalog recommends. If 1" falls short, compare 1-1/2" molded grating. How to read the columns: fiberglass grating load tables.

Uniform load deflection, Strongrate 1" molded grating, 1-1/2" square mesh (catalog page 56)

Clear span	31 psf (150 kg/m²)	72 psf (350 kg/m²)	102 psf (500 kg/m²)	154 psf (750 kg/m²)	205 psf (1,000 kg/m²)	307 psf (1,500 kg/m²)	512 psf (2,500 kg/m²)	Max load, psf (kg/m²)
11-13/16" (300 mm)	< 0.01" (< 0.25 mm)	< 0.01" (< 0.25 mm)	< 0.01" (< 0.25 mm)	< 0.01" (< 0.25 mm)	0.01" (0.26 mm)	0.01" (0.31 mm)	0.03" (0.64 mm)	6,477 (31,625)
17-3/4" (450 mm)	0.01" (0.3 mm)	0.01" (0.38 mm)	0.02" (0.62 mm)	0.04" (0.94 mm)	0.05" (1.22 mm)	0.07" (1.85 mm)	0.11" (2.75 mm)	4,252 (20,759)
23-5/8" (600 mm)	0.04" (0.98 mm)	0.05" (1.24 mm)	0.07" (1.85 mm)	0.11" (2.75 mm)	0.13" (3.35 mm)	0.20" (5.18 mm)	0.35" (8.86 mm)	2,548 (12,439)
29-1/2" (750 mm)	0.05" (1.28 mm)	0.12" (3.05 mm)	0.18" (4.57 mm)	0.27" (6.86 mm)	0.36" (9.15 mm)	—	—	1,628 (7,950)
35-7/16" (900 mm)	0.10" (2.57 mm)	0.28" (7.13 mm)	0.38" (9.62 mm)	—	—	—	—	1,130 (5,518)
47-1/4" (1200 mm)	0.28" (7.1 mm)	0.39" (9.9 mm)	0.49" (12.46 mm)	—	—	—	—	579 (2,827)

Cells are deflection under static load at ambient temperature, as printed in Strongrate’s 2023 catalog (mm), with inches converted; “—” means no value is printed. Halve the loads for impact or dynamic conditions. Confirm the values for your span in the submittal before final design.

Notes

Deflections as printed in the factory catalog (2023), static loads at ambient temperature.
Catalog tables.

Concentrated point load deflection, Strongrate 1" molded grating, 1-1/2" square mesh (catalog pages 56–57)

Clear span	331 lb (150 kg)	772 lb (350 kg)	1,102 lb (500 kg)	1,653 lb (750 kg)	2,205 lb (1,000 kg)	3,307 lb (1,500 kg)	5,512 lb (2,500 kg)	6,614 lb (3,000 kg)
11-13/16" (300 mm)	—	0.02" (0.44 mm)	0.02" (0.59 mm)	0.04" (1.03 mm)	0.05" (1.37 mm)	0.07" (1.78 mm)	0.11" (2.82 mm)	0.14" (3.49 mm)
17-3/4" (450 mm)	0.01" (0.26 mm)	0.03" (0.66 mm)	0.04" (0.89 mm)	0.06" (1.55 mm)	0.08" (2.06 mm)	0.11" (2.67 mm)	0.17" (4.23 mm)	0.21" (5.23 mm)
23-5/8" (600 mm)	0.03" (0.74 mm)	0.06" (1.55 mm)	0.08" (2.02 mm)	0.13" (3.18 mm)	0.18" (4.52 mm)	0.24" (6.12 mm)	—	—
29-1/2" (750 mm)	0.05" (1.26 mm)	0.12" (2.94 mm)	0.15" (3.78 mm)	0.24" (5.99 mm)	0.35" (8.79 mm)	—	—	—
35-7/16" (900 mm)	0.07" (1.78 mm)	0.17" (4.32 mm)	0.22" (5.53 mm)	0.35" (8.81 mm)	0.51" (13.06 mm)	—	—	—
47-1/4" (1200 mm)	0.12" (2.95 mm)	0.29" (7.42 mm)	0.41" (10.38 mm)	0.59" (15.06 mm)	—	—	—	—

Notes

Deflections as printed in the factory catalog (2023), static loads at ambient temperature.
Catalog tables.

Which resins and surfaces can you order?

The DNV-listed model is isophthalic polyester; its fire results apply to that resin. Strongrate’s catalog also lists fire-retardant vinyl ester, food-grade isophthalic and orthophthalic resin for molded grating, with a concave (meniscus) or gritted top, or a solid cover with a checker or grit finish. Resins and temperature limits are compared on molded fiberglass grating.

How is 1" molded grating quoted and shipped?

Made in Nantong, China, and shipped from China. Full containers and project quantities are quoted factory-direct; orders under about 500 sq ft, or needed in under 3 weeks, are referred to US stocking importers. Prices are quoted per project: see fiberglass grating price per square foot, add hold-down clips, and request a quote.

Frequently asked questions

What is the flame spread index of Strongrate 1" molded grating?

The DNV-listed 38×38×25 mm isophthalic model has an ASTM E84-19a flame spread index of 10 and a smoke-developed index of 55, as listed on DNV Type Approval TAF0000191 Rev. 1. Other resins are not covered by that result.

When should I choose 1-1/2" instead of 1" molded grating?

When the 1" load table cannot meet your design load at your span and deflection limit. Then compare the table for the same mesh at 1-1/2" deep on the 1-1/2" molded grating page.

Can I order a sample of the 1" molded grating?

Yes, request one on the samples page.

Molded fiberglass grating
Molded fiberglass (FRP) grating from Strongrate’s Nantong factory by depth and mesh: square, rectangular and mini meshes, the four DNV-listed models with their ASTM E84 results, panel sizes, resins, surfaces and how to get factory pricing.
1-1/2" molded fiberglass grating
Specifications, ASTM E84 results, panel sizes and catalog load tables for Strongrate 1-1/2-inch-deep molded fiberglass grating with a 1-1/2-inch square mesh (DNV-listed model 38×38×38 mm), and how to order it.
Mini mesh fiberglass grating
What mini mesh molded fiberglass grating is, how the ADA 302.3 half-inch opening rule applies to the five mini-mesh patterns in Strongrate’s catalog, their weight, open area, panel sizes and deflection tables, and how to order.
Fiberglass grating clips
Hold-down clips for molded and pultruded fiberglass grating: the STRONGFIX types in Strongrate’s catalog, common US clip types, the Type 316 stainless and 4 ft spacing rules in US guide specifications, and how to order clips with grating.
Fiberglass grating price per sq ft
Fiberglass grating prices per square foot and per panel: dated US market benchmarks, what moves the price, and how Strongrate quotes factory-direct prices per project.

Request a quote

Send span, design load, panel size, quantity and ZIP code for 1" molded grating. Quotes within 1 business day (US Central time).

Request a quote Order a sample

Sources

DNV Type Approval Certificate TAF0000191 Rev. 1, with ASTM E84-19a results and conditions (PDF on Strongrate’s ShipServ supplier profile) (accessed Oct 15, 2026)
Strongrate product catalog “Your Best FRP Solution” (image PDF, Sep 2023), supplied by the site owner (accessed Oct 17, 2026)