Product specification

Rectangular Mesh Fiberglass Grating, 1" × 4" and 1" × 6" Molded

Updated Oct 17, 2026

Strongrate's catalog lists two rectangular meshes: 1" × 4" (25 × 102 mm), 1" (25 mm) deep at 2.7 lb/ft² (13.0 kg/m²), also in heavy duty, and 1" × 6" (25 × 152 mm), 1-1/2" deep at 4.6 lb/ft² (22.5 kg/m²). Choose 1" × 4" to replace existing US rectangular grating; choose 1" × 6" for the DNV-listed vinyl ester model, flame spread index 10.

DNV-listed model: 1" × 6" mesh, 1-1/2" deep

DNV certificate designation: 25.4×152.4×38 mmInch sizes are North American nominals of the metric certificate designation.
Mesh and depth: 1" × 6" (25 × 152 mm), 1-1/2" (38 mm) deepInch sizes are North American nominals of the metric certificate designation.
Resin: Vinyl ester
ASTM E84-19a flame spread index: 10Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to the 1" × 6" model only, not to a 1" × 4" product.
ASTM E84-19a smoke-developed index: 15Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to the 1" × 6" model only, not to a 1" × 4" product.
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" × 4" and 1" × 6" rectangular-mesh molded grating

Mesh	Depth	Bar width (as printed)	Weight	Open area	Span direction
1" × 4" (25 × 102 mm)¹	1" (25 mm)¹	1/4" / 3/16" (6.5 / 5.0 mm)¹	2.7 lb/ft² (13.0 kg/m²)¹	67%¹	Width or length¹
1" × 4" (25 × 102 mm)¹	1" (25 mm) heavy duty¹	3/8" / 5/16" (9.5 / 8.0 mm)¹	3.2 lb/ft² (15.6 kg/m²)¹	67%¹	Panel width¹
1" × 6" (25 × 152 mm)¹	1-1/2" (38 mm)¹	3/8" / 1/4" (9.0 / 6.5 mm)¹	4.6 lb/ft² (22.5 kg/m²)¹	63%¹	Panel length¹

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).

The DNV fire results cover the 1" × 6" vinyl ester model only, not the 1" × 4" mesh. The catalog also lists 1-1/2" × 4" and 1-1/2" × 6" meshes at 1-1/2" deep; name them in your quote request if you need them.

What panel sizes are available?

1" × 4" (25 × 102 mm) mesh, 1" (25 mm) deep: 4 ft × 12 ft (1220 × 3660 mm); 3 ft × 10 ft (921 × 3050 mm)
1" × 6" (25 × 152 mm) mesh, 1-1/2" deep: 4 ft × 12 ft (1220 × 3660 mm); 3 ft × 10 ft (921 × 3050 mm)

Panel sizes as printed in Strongrate’s catalog. Send your layout or drawings with the quote request. Sizes and weights of every product: fiberglass grating sizes, weight and open area.

How does rectangular mesh carry load?

A rectangular mesh has different bar spacing in each direction, so the catalog prints a span direction for each row: the standard 1" × 4" spans either way, the heavy-duty 1" × 4" across the panel width, and the 1" × 6" along the panel length. Read the deflection at your clear span below; halve the loads for impact. How to read the columns: fiberglass grating load tables.

Uniform load deflection, Strongrate 1" × 4" mesh, 1" deep, standard and heavy duty (catalog pages 61–62, printed as 25 × 100 mm mesh)

Clear span	Depth	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)	1" (25 mm)	—	0.01" (0.28 mm)	0.01" (0.37 mm)	0.02" (0.51 mm)	0.02" (0.63 mm)	0.03" (0.73 mm)	0.04" (1.04 mm)	5,397 (26,350)
11-13/16" (300 mm)	1" (25 mm) HD	—	—	—	0.01" (0.26 mm)	0.02" (0.53 mm)	0.03" (0.79 mm)	0.05" (1.32 mm)	6,747 (32,940)
17-3/4" (450 mm)	1" (25 mm)	0.02" (0.53 mm)	0.03" (0.72 mm)	0.05" (1.36 mm)	0.09" (2.16 mm)	0.11" (2.86 mm)	0.14" (3.54 mm)	0.28" (7.22 mm)	3,098 (15,128)
17-3/4" (450 mm)	1" (25 mm) HD	0.01" (0.29 mm)	0.02" (0.51 mm)	0.03" (0.76 mm)	0.05" (1.27 mm)	0.06" (1.53 mm)	0.09" (2.29 mm)	0.15" (3.82 mm)	3,873 (18,910)
23-5/8" (600 mm)	1" (25 mm)	0.03" (0.73 mm)	0.04" (0.92 mm)	0.07" (1.86 mm)	0.10" (2.46 mm)	0.14" (3.68 mm)	0.22" (5.54 mm)	0.36" (9.22 mm)	2,599 (12,688)
23-5/8" (600 mm)	1" (25 mm) HD	0.04" (0.89 mm)	0.05" (1.27 mm)	0.08" (2.03 mm)	0.13" (3.3 mm)	0.17" (4.32 mm)	0.25" (6.35 mm)	—	3,248 (15,860)
29-1/2" (750 mm)	1" (25 mm)	0.06" (1.65 mm)	0.11" (2.86 mm)	0.15" (3.71 mm)	0.22" (5.63 mm)	0.33" (8.32 mm)	—	—	2,079 (10,150)
29-1/2" (750 mm)	1" (25 mm) HD	0.07" (1.87 mm)	0.12" (3.06 mm)	0.18" (4.57 mm)	0.28" (7.12 mm)	0.37" (9.41 mm)	—	—	2,599 (12,688)
35-7/16" (900 mm)	1" (25 mm)	0.08" (2.13 mm)	0.14" (3.64 mm)	0.26" (6.61 mm)	0.39" (9.87 mm)	0.49" (12.57 mm)	—	—	1,493 (7,289)
35-7/16" (900 mm)	1" (25 mm) HD	0.15" (3.87 mm)	0.23" (5.84 mm)	0.35" (8.89 mm)	—	—	—	—	1,866 (9,111)
47-1/4" (1200 mm)	1" (25 mm)	0.22" (5.62 mm)	0.33" (8.37 mm)	0.59" (14.91 mm)	—	—	—	—	939 (4,587)
47-1/4" (1200 mm)	1" (25 mm) HD	0.30" (7.62 mm)	0.50" (12.71 mm)	—	—	—	—	—	1,174 (5,734)

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" × 4" mesh, 1" deep, standard and heavy duty (catalog pages 62–63, printed as 25 × 100 mm mesh)

Clear span	Depth	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)	1" (25 mm)	0.01" (0.29 mm)	0.03" (0.69 mm)	0.04" (0.99 mm)	0.06" (1.5 mm)	0.08" (2.13 mm)	0.11" (2.89 mm)	0.19" (4.74 mm)	—
11-13/16" (300 mm)	1" (25 mm) HD	—	0.02" (0.52 mm)	0.03" (0.74 mm)	0.04" (1.13 mm)	0.06" (1.6 mm)	0.09" (2.17 mm)	0.14" (3.56 mm)	—
17-3/4" (450 mm)	1" (25 mm)	0.02" (0.47 mm)	0.04" (1.1 mm)	0.06" (1.43 mm)	0.09" (2.25 mm)	0.13" (3.2 mm)	0.17" (4.33 mm)	—	—
17-3/4" (450 mm)	1" (25 mm) HD	0.01" (0.35 mm)	0.03" (0.82 mm)	0.04" (1.07 mm)	0.07" (1.69 mm)	0.09" (2.4 mm)	0.13" (3.25 mm)	0.17" (4.39 mm)	—
23-5/8" (600 mm)	1" (25 mm)	0.03" (0.69 mm)	0.06" (1.63 mm)	0.08" (2.12 mm)	0.13" (3.34 mm)	0.19" (4.74 mm)	0.25" (6.42 mm)	—	—
23-5/8" (600 mm)	1" (25 mm) HD	0.02" (0.52 mm)	0.05" (1.22 mm)	0.06" (1.59 mm)	0.10" (2.5 mm)	0.14" (3.56 mm)	0.19" (4.81 mm)	0.29" (7.36 mm)	—
29-1/2" (750 mm)	1" (25 mm)	0.05" (1.32 mm)	0.12" (3.08 mm)	0.16" (3.97 mm)	0.25" (6.28 mm)	0.36" (9.22 mm)	—	—	—
29-1/2" (750 mm)	1" (25 mm) HD	0.04" (0.99 mm)	0.09" (2.31 mm)	0.12" (2.97 mm)	0.19" (4.71 mm)	0.27" (6.92 mm)	0.37" (9.34 mm)	—	—
35-7/16" (900 mm)	1" (25 mm)	0.07" (1.87 mm)	0.18" (4.53 mm)	0.23" (5.8 mm)	0.36" (9.24 mm)	—	—	—	—
35-7/16" (900 mm)	1" (25 mm) HD	0.06" (1.4 mm)	0.13" (3.4 mm)	0.17" (4.35 mm)	0.27" (6.93 mm)	0.36" (9.23 mm)	—	—	—
47-1/4" (1200 mm)	1" (25 mm)	0.12" (3.09 mm)	0.31" (7.78 mm)	0.43" (10.89 mm)	0.62" (15.8 mm)	—	—	—	—
47-1/4" (1200 mm)	1" (25 mm) HD	0.09" (2.32 mm)	0.23" (5.84 mm)	0.32" (8.17 mm)	0.47" (11.85 mm)	—	—	—	—

Notes

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

Uniform load deflection, Strongrate 1" × 6" mesh, 1-1/2" deep (catalog pages 64–65)

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" (0.37 mm)	0.02" (0.53 mm)	0.03" (0.65 mm)	0.03" (0.76 mm)	0.04" (1.08 mm)	5,195 (25,366)
17-3/4" (450 mm)	0.02" (0.55 mm)	0.03" (0.75 mm)	0.06" (1.41 mm)	0.09" (2.24 mm)	0.12" (2.97 mm)	0.14" (3.68 mm)	0.30" (7.5 mm)	2,983 (14,563)
23-5/8" (600 mm)	0.03" (0.76 mm)	0.04" (0.96 mm)	0.08" (1.93 mm)	0.10" (2.56 mm)	0.15" (3.82 mm)	0.23" (5.75 mm)	0.38" (9.58 mm)	2,502 (12,214)
29-1/2" (750 mm)	0.07" (1.71 mm)	0.12" (2.97 mm)	0.15" (3.85 mm)	0.23" (5.85 mm)	0.34" (8.64 mm)	0.49" (12.43 mm)	—	2,001 (9,771)
35-7/16" (900 mm)	0.09" (2.21 mm)	0.15" (3.78 mm)	0.27" (6.87 mm)	0.40" (10.25 mm)	0.51" (13.06 mm)	—	—	1,437 (7,017)
47-1/4" (1200 mm)	0.23" (5.87 mm)	0.34" (8.69 mm)	0.61" (15.49 mm)	—	—	—	—	904 (4,416)

Notes

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

Concentrated point load deflection, Strongrate 1" × 6" mesh, 1-1/2" deep (catalog pages 65–66)

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)	0.01" (0.28 mm)	0.03" (0.66 mm)	0.04" (0.95 mm)	0.06" (1.44 mm)	0.08" (2.04 mm)	0.11" (2.76 mm)	0.18" (4.53 mm)	—
17-3/4" (450 mm)	0.02" (0.45 mm)	0.04" (1.05 mm)	0.05" (1.37 mm)	0.08" (2.15 mm)	0.12" (3.06 mm)	0.16" (4.14 mm)	0.22" (5.54 mm)	—
23-5/8" (600 mm)	0.03" (0.66 mm)	0.06" (1.55 mm)	0.08" (2.03 mm)	0.13" (3.19 mm)	0.18" (4.53 mm)	0.24" (6.14 mm)	—	—
29-1/2" (750 mm)	0.05" (1.26 mm)	0.12" (2.95 mm)	0.15" (3.79 mm)	0.24" (6.01 mm)	0.35" (8.82 mm)	—	—	—
35-7/16" (900 mm)	0.07" (1.79 mm)	0.17" (4.33 mm)	0.22" (5.55 mm)	0.35" (8.84 mm)	0.46" (11.78 mm)	—	—	—
47-1/4" (1200 mm)	0.12" (2.96 mm)	0.29" (7.44 mm)	0.41" (10.41 mm)	0.59" (15.11 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 1" × 6" model is vinyl ester, the resin US suppliers use for harsher chemical service; Strongrate's catalog gives 230°F (110°C) as the maximum temperature of its fire-retardant vinyl ester. The catalog also lists isophthalic, food-grade isophthalic and orthophthalic resin, with concave or gritted tops. Resins are compared on molded fiberglass grating.

How is rectangular mesh 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

Why does the DNV certificate list the rectangular model as 25.4×152.4×38?

The certificate gives the model size in millimeters. In 25.4×152.4×38, the first two figures are exactly 1" and 6", the mesh, and 38 mm is the 1-1/2" depth. It is not the 1" × 4" mesh, which is a separate catalog product with no DNV listing.

Can Strongrate grating replace existing 1" × 4" grating?

Its catalog 1" × 4" mesh at 1" (25 mm) deep is the like-for-like option; the 1" × 6" model is 1-1/2" deep and needs different support heights. Send the existing mesh, depth, panel size and span with your quote request.

Which way should rectangular mesh run on a walkway?

Structurally, in the span direction the catalog prints for the mesh. On ADA accessible routes, the long dimension of each opening must also be perpendicular to the dominant direction of travel; for small openings, see mini mesh grating.

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.
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.
1" molded fiberglass grating
Specifications, ASTM E84 results, panel sizes and catalog load tables for Strongrate 1-inch-deep molded fiberglass grating with a 1-1/2-inch square mesh (DNV-listed model 38×38×25 mm), and how to order it.
2" molded fiberglass grating
When to specify 2-inch-deep molded fiberglass grating with a 2-inch square mesh: Strongrate catalog weight, open area, panel sizes and deflection tables, and how to order it.
ASTM E84 fire rating
What ASTM E84 Class 1 (Class A) means for FRP grating, the flame spread and smoke-developed indexes of Strongrate’s six DNV-listed models, and how to specify fire performance.

Request a quote

Send mesh, depth, resin, span, panel size, quantity and ZIP code for rectangular mesh grating. Quotes within 1 business day (US Central time).

Request a quote Order a sample

Sources

Strongrate product catalog “Your Best FRP Solution” (image PDF, Sep 2023), supplied by the site owner (accessed Oct 17, 2026)
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)
U.S. Access Board, Guide to the ADA Standards, Chapter 3: Floor and Ground Surfaces (accessed Oct 15, 2026)