Product family
Molded Fiberglass Grating
Updated
Molded fiberglass grating is cast as one piece with strength in both directions. Strongrate's catalog lists square, rectangular and mini meshes from 1/2" (13 mm) to 2-9/16" (65 mm) deep, with 30–35% glass. Four of its molded models are on DNV Type Approval TAF0000191 Rev. 1, with ASTM E84-19a flame spread indexes of 5 to 15. Choose the depth by span and load, then the mesh.
Which mesh and depth fit your project?
Start with the load and the clear span between supports, which set the depth; each product page has the catalog load tables. Then choose the mesh: square mesh for general flooring and walkways, rectangular mesh to match existing 1" × 4" grating or for the DNV-listed vinyl ester model, and mini mesh for accessible routes or where small items must not drop through.
| Configuration | Depth | Mesh | Weight (catalog) | Open area (catalog) | DNV-listed model and resin | ASTM E84 flame spread index |
|---|---|---|---|---|---|---|
| 1" square mesh | 1" (25 mm)1 | 1-1/2" × 1-1/2" (38 × 38 mm) | 2.5 lb/ft² (12.3 kg/m²)2 | 68%2 | 38×38×25 mm, isophthalic polyester1 | 103 |
| 1-1/4" square mesh, fire-retardant | 1-1/4" (32 mm)1 | 1-1/2" × 1-1/2" (38 × 38 mm) | — | — | 38×38×32 mm, fire-retardant orthophthalic polyester1 | 53 |
| 1-1/2" square mesh | 1-1/2" (38 mm)1 | 1-1/2" × 1-1/2" (38 × 38 mm) | 4.0 lb/ft² (19.5 kg/m²)2 | 68%2 | 38×38×38 mm, isophthalic polyester1 | 153 |
| 2" square mesh | 2" (50 mm)2 | 2" × 2" (51 × 51 mm) | 4.4–4.8 lb/ft² (21.5–23.5 kg/m²)2 | 78%2 | Not listed | — |
| 1" × 4" rectangular mesh, standard and heavy duty | 1" (25 mm)2 | 1" × 4" (25 × 102 mm) | 2.7–3.2 lb/ft² (13.0–15.6 kg/m²)2 | 67%2 | Not listed | — |
| 1" × 6" rectangular mesh | 1-1/2" (38 mm)1 | 1" × 6" (25 × 152 mm) | 4.6 lb/ft² (22.5 kg/m²)2 | 63%2 | 25.4×152.4×38 mm, vinyl ester1 | 104 |
| Mini mesh (micro-mesh), five patterns | 9/16" (14 mm) to 2-3/8" (60 mm)2 | 3/4" × 3/4" openings on 1-1/2" × 1-1/2" centers (19 × 19 / 38 × 38 mm) and four other patterns2 | 3.4 lb/ft² (16.8 kg/m²)2 | 30%2 | Not listed | — |
Notes
- 1Inch sizes are North American nominals of the metric certificate designation.
- 2Values as printed in the factory catalog (2023); confirmed in your quote and submittal drawings.
- 3Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to this model only.
- 4Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to the 1" × 6" model only, not to a 1" × 4" product.
- Fire data on the certificate applies to these six models only.
The catalog also lists heavy-duty (HD) versions of the 1-1/2" square mesh at 2" (50 mm), 2-3/8" (60 mm), 2-9/16" (65 mm) deep, other rectangular meshes and metric meshes; name them in your quote request. Every product's sizes and weights are compared on fiberglass grating sizes, weight and open area, and span tables explained on fiberglass grating load tables.
- DNV-listed1" molded grating, 1-1/2" square meshDNV-listed model 38×38×25 mm, isophthalic. Catalog: 2.5 lb/ft² (12.3 kg/m²), 68% open, with load tables.
- DNV-listed1-1/2" molded grating, 1-1/2" square meshDNV-listed model 38×38×38 mm, isophthalic. Catalog: 4.0 lb/ft² (19.5 kg/m²), 68% open, with load tables.
- In the catalog2" molded grating, 2" square meshFor loads and spans beyond 1-1/2" grating. Catalog: 4.4–4.8 lb/ft² (21.5–23.5 kg/m²), 78% open, with load tables.
- DNV-listed (1" × 6")Rectangular mesh fiberglass grating (1" × 4", 1" × 6")1" × 4" mesh 1" deep, standard and heavy duty, and the DNV-listed 1" × 6" mesh 1-1/2" deep in vinyl ester, with load tables.
- In the catalogMini mesh fiberglass gratingFive catalog patterns for accessible routes and areas where parts must not drop through, with the ADA opening rule explained.
What panel sizes does molded grating come in?
Most of Strongrate's inch meshes are printed in 4 ft × 12 ft (1220 × 3660 mm), 4 ft × 8 ft (1220 × 2440 mm) and 3 ft × 10 ft (921 × 3050 mm), close to the common US sizes, and many also in 5 ft × 13.12 ft (1524 × 4000 mm). Each product page lists its sizes. On site, molded grating is cut with carbide or diamond tooling and the cut edges sealed with resin; see how to cut fiberglass grating and how to install fiberglass grating.
Which resin should you choose for molded grating?
Match the resin to the chemicals and temperature on site. Strongrate's catalog lists four fire-retardant resin systems for molded grating, and three of them are on its DNV certificate: isophthalic polyester, vinyl ester and fire-retardant orthophthalic polyester. The catalog's chemical-resistance chart is on fiberglass grating specifications.
| Code | Resin | Use | Corrosion resistance | Products | Max temperature |
|---|---|---|---|---|---|
| VEFR1 | Vinyl ester | Superior corrosion resistance, fire retardant | Excellent | Molded and pultruded | 230°F (110°C)1 |
| IFR1 | Isophthalic polyester | Industrial-grade corrosion resistance, fire retardant | Very good | Molded and pultruded | 176°F (80°C)1 |
| FG1 | Isophthalic polyester, food grade | Food-grade corrosion resistance, fire retardant | Very good | Molded and pultruded | 176°F (80°C)1 |
| OFR1 | Orthophthalic polyester | Moderate corrosion resistance, fire retardant | Moderate | Molded only | 158°F (70°C)1 |
Notes
- 1Maximum service temperatures as printed in the catalog’s resin table.
- General information from resin makers’ data, as printed in the catalog; testing in the actual environment is recommended.
Which surfaces and special types are listed?
- Concave (meniscus) top: the standard molded surface.
- Gritted top: slip coefficient 0.91 (ASTM D2047) for the normal grit surface, per the catalog.
- Solid cover with a checker or grit finish, for trench covers and solid walkways; see trench covers and drain grates.
- Conductive grating, 1 × 10⁵ to 5 × 10⁵ ohms, for spark-sensitive plants.
- Transparent grating, pure resin with little or no pigment.
Need longer spans or higher stiffness than molded grating gives? Compare molded vs pultruded fiberglass grating and pultruded fiberglass grating.
How is 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, lead times, MOQ and shipping and request a quote.
Frequently asked questions
Will Strongrate molded panels fit frames made for another maker’s panels?
Check before ordering: Strongrate’s catalog sizes are metric (for example 4 ft × 12 ft (1220 × 3660 mm)). One US maker’s guide specification holds molded grating to within 1/16" (1.6 mm) either way on depth and mesh. Send the frame’s clear opening, the depth and the mesh with your quote request so the fit can be confirmed.
Is there a 1-1/4" deep Strongrate molded grating?
The DNV certificate lists one: model 38×38×32 mm, read as a 1-1/2" square mesh 1-1/4" (32 mm) deep, in fire-retardant orthophthalic polyester, with an ASTM E84-19a flame spread index of 5. The 2023 catalog does not print a 32 mm depth for that mesh, so ask for it by model in your quote request.
Request a quote
Quote this configuration: send mesh, depth, resin, surface, panel size, quantity and ZIP code. Quotes within 1 business day (US Central time).
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)
- Fibergrate molded grating guide specification (Section 06610); Strongwell Section 06 74 13 molded grating specification (accessed Oct 15, 2026)
- Grating Pacific, Molded Fiberglass Grating Sizes (PDF) (accessed Oct 15, 2026)