---
title: "Molded vs Pultruded Fiberglass Grating: Which to Choose"
description: "Molded vs pultruded grating compared: how each is made, glass content, stiffness and span, weight, open area, surfaces and cost, with a decision table by use."
url: https://www.strongrate.us/compare/molded-vs-pultruded-fiberglass-grating/
markdown: https://www.strongrate.us/compare/molded-vs-pultruded-fiberglass-grating.md
published: 2026-10-16
updated: 2026-10-17
---

[Home](https://www.strongrate.us/) › [Resources](https://www.strongrate.us/resources/) › [Molded vs pultruded](https://www.strongrate.us/compare/molded-vs-pultruded-fiberglass-grating/)

# Molded vs Pultruded Fiberglass Grating

_Updated Oct 17, 2026_

Molded vs pultruded grating comes down to span and use. Choose molded, a one-piece panel with strength in both directions, for trench covers, general flooring, chemical plants and cut-outs. Choose pultruded, which Strongrate’s catalog puts at 60–65% glass against 30–35% for molded and US makers market as about twice as stiff, for platforms, mezzanines and longer spans.

## What is the difference between molded and pultruded grating?

The difference is how each is made. Molded grating is cast as a one-piece panel in a mold, so it has bars and strength in both directions. Pultruded grating is assembled from pultruded bearing bars joined by cross rods, commonly 6" (152 mm) on center, so its strength runs mainly along the bars.

That makes molded grating resin-rich, typically about 30–35% glass by weight, and pultruded grating glass-rich, typically about 65–70%. US makers market pultruded grating as about twice as stiff as molded, which is why it spans farther between supports. Strongrate makes both types in Nantong, China; its catalog gives 30–35% glass for its molded grating and 60–65% for pultruded, and its DNV certificate lists four molded and two pultruded models.

_Diagram: Molded grating: one-piece square mesh with bars in both directions. Schematic — not to scale._

_Diagram: Pultruded I-bar grating: bearing bars joined by cross rods. Schematic — not to scale._

_Diagram: Pultruded T-bar grating: wide top flanges form most of the walking surface. Schematic — not to scale._

## How do molded and pultruded grating compare side by side?

**Molded vs pultruded fiberglass grating: industry-typical values from US makers (not Strongrate data)**

| Molded vs pultruded grating | Molded grating | Pultruded grating |
| --- | --- | --- |
| How it is made | One-piece panel cast in a mold | Pultruded bearing bars joined by cross rods |
| Strength direction | Both directions | Along the bearing bars |
| Glass content by weight (%) | about 30–35% [note 1] | about 65–70% [note 1] |
| Stiffness | Baseline | Marketed as about 2× stiffer than molded [note 2] |
| Common depths (in) | 1", 1-1/2" and 2" (25, 38 and 51 mm) | 1" and 1-1/2" (25 and 38 mm) I-bar; 2" (51 mm) T-bar |
| Open area (%) | about 70% (1-1/2" square mesh) [note 3] | I-bar about 40% or 60%; T-bar about 33% or 50% [note 4] |
| Weight at 1-1/2" (38 mm) depth (lb/ft²; pultruded: 60%-open I-bar) | 3.75–3.94 lb/ft² (18.3–19.2 kg/m²) [note 3] | 2.8–3.0 lb/ft² (13.7–14.6 kg/m²) [note 3] |
| Panel sizes (ft) | 3 ft × 10 ft, 4 ft × 8 ft, 4 ft × 12 ft and 5 ft × 10 ft (915 × 3050, 1220 × 2440, 1220 × 3660 and 1525 × 3050 mm) [note 5] | 3, 4 or 5 ft (915, 1220 or 1525 mm) wide, up to 20 ft (6.10 m) long [note 5] |
| Slip-resistant surface | Concave (meniscus) top or applied quartz grit | Bonded grit |
| Typical uses | Trench covers, general flooring, chemical plants | Platforms, mezzanines, bridge walkways |

_Compiled from US makers’ published figures, accessed Oct 15, 2026. Product pages: [molded fiberglass grating](https://www.strongrate.us/molded-fiberglass-grating/) and [pultruded fiberglass grating](https://www.strongrate.us/pultruded-fiberglass-grating/)._

Notes:

1. Typical published figure, not Strongrate data.
2. A marketing comparison; compare actual load tables.
3. Typical published figures from US makers, not Strongrate data.
4. Typical published options from US makers, not Strongrate data.
5. Industry norms; Strongrate sizes are stated in your quote.

**Strongrate molded vs pultruded grating: summary of its 2023 product catalog**

| Strongrate catalog | Molded grating | Pultruded grating |
| --- | --- | --- |
| Glass content by weight | 30–35% | 60–65% |
| Range | 4 square, 10 rectangular and 5 mini meshes [note 1] | 36 types: T-bar, I-bar, and HI, HL and SI I-bar series [note 1] |
| Depths | 1/2" (13 mm) to 2-9/16" (65 mm) [note 1] | 1" (25 mm) to 3" (76 mm) [note 1] |
| Weight | 1.2–10.7 lb/ft² (5.8–52.0 kg/m²) [note 1] | 1.7–15.1 lb/ft² (8.5–73.6 kg/m²) [note 1] |
| Open area | 52–84% square mesh; 30–60% mini mesh [note 1] | 40–83% I-bar; 12–50% T-bar [note 1] |
| Panel sizes | 4 ft × 12 ft (1220 × 3660 mm), 4 ft × 8 ft (1220 × 2440 mm) and others by mesh [note 1] | Up to 5 ft × 20 ft (1524 × 6100 mm) [note 1] |
| Strength direction | Both directions; either panel edge can span | Along the bearing bars |

_Values from Strongrate’s 2023 catalog; confirmed in your quote and submittal drawings before design use. Every mesh, depth and type with its weight, open area and panel sizes: [fiberglass grating sizes, weight and open area](https://www.strongrate.us/resources/fiberglass-grating-sizes-weight-and-open-area/)._

Notes:

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

## Which carries more load at a given span?

US makers market pultruded grating as about twice as stiff as molded, which is why it is chosen for longer spans; treat that as a marketing comparison and check real tables. Do not compare makers’ tables at face value: published safe loads rest on safety factors from 2:1 to 5:1 on ultimate capacity. Compare deflection at your span and design load, using tables tested to the ANSI/ACMA FGMC grating manual.

Common walkway deflection limits are 3/8" (9.5 mm) or L/120 for comfort and 1/4" (6.4 mm) where a firmer feel is wanted.

Strongrate’s 2023 catalog prints deflection tables for its molded meshes by depth and for its pultruded types under uniform and line loads (molded also under point loads), static at ambient temperature, and says to halve the loads for impact or dynamic conditions. The tables are on [fiberglass grating load tables](https://www.strongrate.us/resources/fiberglass-grating-load-tables/); confirm values in your quote and submittal drawings before design use.

## Which weighs less per square foot?

At 1-1/2" (38 mm) and 2" (51 mm) depths, published pultruded weights are lower than molded weights; at 1" (25 mm) they are about the same. In Strongrate’s catalog, its 60%-open I-bar and 50%-open T-bar types weigh less than its square-mesh molded grating at all three depths. Mesh and open area change weight too, so use the figure for the exact product.

**Weight of molded and pultruded fiberglass grating by depth: industry-typical values and Strongrate’s catalog**

| Depth | Molded, square or 1" × 4" mesh, typical (lb/ft²) | Pultruded profile | Pultruded, typical (lb/ft²) | Strongrate molded (catalog) | Strongrate pultruded (catalog) |
| --- | --- | --- | --- | --- | --- |
| 1" (25 mm) | 2.5–2.8 lb/ft² (12.2–13.7 kg/m²) [note 1] | 60%-open I-bar | 2.5–2.6 lb/ft² (12.2–12.7 kg/m²) [note 1] | 2.5 lb/ft² (12.3 kg/m²), 1-1/2" square mesh [note 2] | 2.3 lb/ft² (11.2 kg/m²), I-6010 [note 2] |
| 1-1/2" (38 mm) | 3.75–3.94 lb/ft² (18.3–19.2 kg/m²) [note 1] | 60%-open I-bar | 2.8–3.0 lb/ft² (13.7–14.6 kg/m²) [note 1] | 4.0 lb/ft² (19.5 kg/m²), 1-1/2" square mesh [note 2] | 3.3 lb/ft² (16.1 kg/m²), I-6015 [note 2] |
| 2" (51 mm) | 4.0–4.5 lb/ft² (19.5–22.0 kg/m²) [note 1] | 50%-open T-bar | 3.1–3.4 lb/ft² (15.1–16.6 kg/m²) [note 1] | 4.4–4.8 lb/ft² (21.5–23.5 kg/m²), 2" square mesh [note 2] | 3.2 lb/ft² (15.7 kg/m²), T-5020 [note 2] |

_Typical values from US makers’ published data. Strongrate values are from its 2023 catalog, which prints two weights for the 2" square mesh at 2" depth. I-6010 and I-6015 are 60% open and T-5020 is 50% open in the catalog. Full chart: [sizes, weight and open area](https://www.strongrate.us/resources/fiberglass-grating-sizes-weight-and-open-area/)._

Notes:

1. Typical published figures from US makers, not Strongrate data.
2. Values as printed in the factory catalog (2023); confirmed in your quote and submittal drawings.

## Which has more open area, and which can meet the ADA opening rule?

Standard molded grating is about 70% open in 1-1/2" square mesh, against about 40% or 60% for pultruded I-bar and 33% or 50% for T-bar. For an accessible route, ADA 302.3 bars openings that pass a 1/2" (13 mm) sphere; mini-mesh molded grating sold for ADA use, with a 3/4" (19 mm) top mesh over a 1-1/2" (38 mm) base, is typically about 44% open.

On an accessible route, elongated openings, such as the slots between pultruded bars, must run with the long dimension perpendicular to the dominant direction of travel. Strongrate’s catalog lists its square-mesh molded grating at 52–84% open, its mini meshes at 30–60%, and its pultruded types at 40–83% (I-bar) and 12–50% (T-bar); check the measured clear opening before any accessible-route use. See [mini mesh ADA grating](https://www.strongrate.us/molded-fiberglass-grating/mini-mesh-ada/).

## Which is better for chemical and corrosive service?

Chemical resistance depends on the resin system. US grating resins include isophthalic polyester for general industrial use, vinyl ester for harsher chemical service, food-grade isophthalic and phenolic for marine and offshore work. Molded grating is a common choice for chemical plants, and on pultruded grating drilling can compromise the corrosion barrier, so seal every hole.

Strongrate’s catalog lists fire-retardant vinyl ester and isophthalic polyester (including a food-grade isophthalic) for both molded and pultruded grating, and orthophthalic polyester for molded only; its six DNV-listed models use vinyl ester, isophthalic and orthophthalic. The catalog’s chemical-resistance chart rates each resin by chemical; it is on [fiberglass grating specifications](https://www.strongrate.us/resources/fiberglass-grating-specifications/). Send your chemicals, concentrations and temperatures with your [quote request](https://www.strongrate.us/request-quote/).

## Does pultruded grating cost more than molded grating?

Usually, up front. A US distributor notes that pultruded grating usually costs more upfront, and FRP price guides (2025 or undated, read Oct 15, 2026) put molded grating at about $12–$18 per sq ft against $20–$28 for pultruded. It is not a rule: one US maker has priced its stocked pultruded grating at parity with equivalent molded grating since 2017.

**Molded vs pultruded grating price benchmarks (USD per sq ft, published guides; not Strongrate prices)**

| Grating type | Reported range (USD/sq ft) | Basis |
| --- | ---: | --- |
| Molded | $12–$18 [note 1] | FRP vendor price guides (2025 or undated, read Oct 15, 2026) |
| Specialty-resin molded | $22–$30 [note 1] | FRP vendor price guides (2025 or undated, read Oct 15, 2026) |
| Pultruded | $20–$28 [note 1] | FRP vendor price guides (2025 or undated, read Oct 15, 2026) |

_Grit adds about $1–$3 per sq ft in the same guides. Strongrate prices are quoted per project; see [fiberglass grating price](https://www.strongrate.us/pricing/fiberglass-grating-price/)._

Notes:

1. Reported ranges from vendor price guides (2025 or undated, read Oct 15, 2026), not seller quotes and not Strongrate prices.

## Molded or pultruded: which should you choose?

Use the table as a first pass, then confirm with load tables at your span. Two cases need care with Strongrate grating: vehicle traffic, where only its HI high-load pultruded types have catalog spans under wheel loads, subject to your engineer’s review; and federally funded projects under Build America, Buy America, which China-made grating does not qualify for.

**Molded or pultruded fiberglass grating: decision table by application**

| If your project needs | Usually choose | Why |
| --- | --- | --- |
| [Trench covers and drain grates](https://www.strongrate.us/applications/trench-covers-and-drain-grates/) | Molded | A typical molded use; one piece with strength in both directions |
| Chemical plant flooring | Molded, in a resin chosen for the chemicals | A typical molded use; vinyl ester for harsher chemical service |
| General flooring and short walkway spans | Molded | A typical molded use |
| Many cut-outs and penetrations | Molded | Small openings can be cut without added support (one supplier) [note 1] |
| Platforms and mezzanines | Pultruded | A typical pultruded use |
| Longer spans between supports | Pultruded | Marketed as about 2× stiffer than molded [note 2] |
| Bridge walkways | Pultruded | A typical pultruded use |
| Least weight at 1-1/2" (38 mm) depth | Pultruded I-bar | 2.8–3.0 lb/ft² (13.7–14.6 kg/m²) against 3.75–3.94 lb/ft² (18.3–19.2 kg/m²) for molded (typical) [note 3] |
| [Accessible route with 1/2" (13 mm) openings](https://www.strongrate.us/molded-fiberglass-grating/mini-mesh-ada/) | Molded mini-mesh, or pultruded with checked openings set across the travel direction | Openings must not pass a 1/2" (13 mm) sphere |
| Lowest upfront price | Usually molded | Pultruded usually costs more upfront (US distributor) |
| Vehicle traffic (AASHTO H-20) | A vehicle-rated product; of Strongrate’s range, only the HI high-load pultruded types have catalog wheel-load spans, with engineer review [note 4] | US suppliers rate heavy-duty molded or deep pultruded grating to H-20 [note 5] |
| [Federally funded project under BABA](https://www.strongrate.us/buy-direct/buy-america-baba/) | A US-made product | China-made FRP grating does not qualify for BABA-covered projects |

_A first-pass guide built from US makers’ published guidance; the project engineer makes the final selection._

Notes:

1. Depends on depth and load; confirm with the load table and an engineer.
2. A marketing comparison; compare actual load tables.
3. Typical published figures from US makers, not Strongrate data.
4. Values as printed in the factory catalog (2023); confirmed in your quote and submittal drawings.
5. Ratings of other makers’ products, not Strongrate ratings.

## Which Strongrate molded and pultruded models are documented?

Six Strongrate models have documented data today, all from DNV Type Approval TAF0000191 Rev. 1: four molded and two pultruded. Their ASTM E84-19a flame spread indexes run from 5 to 20, all at or below 25. The approval is a fire-technical evaluation only; it does not cover load capacity.

**Strongrate molded and pultruded grating models on DNV Type Approval TAF0000191 Rev. 1, with ASTM E84-19a results**

| Type | Model (size) | Resin | Flame spread index | Smoke-developed index |
| --- | --- | --- | ---: | ---: |
| Molded | 1-1/2" × 1-1/2" (38 × 38 mm) square mesh, 1" (25 mm) deep [note 1] | Isophthalic polyester | 10 [note 2] | 55 [note 2] |
| Molded | 1-1/2" × 1-1/2" (38 × 38 mm) square mesh, 1-1/4" (32 mm) deep [note 1] | Fire-retardant orthophthalic polyester | 5 [note 2] | 250 [note 2] |
| Molded | 1-1/2" × 1-1/2" (38 × 38 mm) square mesh, 1-1/2" (38 mm) deep [note 1] | Isophthalic polyester | 15 [note 2] | 30 [note 2] |
| Molded | 1" × 6" (25 × 152 mm) rectangular mesh, 1-1/2" (38 mm) deep [note 1] | Vinyl ester | 10 [note 3] | 15 [note 3] |
| Pultruded | I 6015 I-bar [note 4] | Isophthalic polyester | 20 [note 2] | 400 [note 2] |
| Pultruded | T5020 T-bar [note 4] | Vinyl ester | 20 [note 2] | 300 [note 2] |

_Strongrate’s catalog lists type I-6015 at 1-1/2" (38 mm) deep and T-5020 at 2" (50 mm): see [1-1/2" I-bar grating](https://www.strongrate.us/pultruded-fiberglass-grating/i-bar-1-5-inch/) and [2" T-bar grating](https://www.strongrate.us/pultruded-fiberglass-grating/t-bar-2-inch/). Details: [ASTM E84 Class 1 fire rating](https://www.strongrate.us/resources/astm-e84-class-1-fire-rating/)._

Notes:

1. Inch sizes are North American nominals of the metric certificate designation.
2. Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to this model only.
3. Result as listed on DNV certificate TAF0000191 Rev. 1 (ASTM E84-19a); applies to the 1" × 6" model only, not to a 1" × 4" product.
4. Bar depth and open area are not stated on the certificate.

- Values as printed in the factory catalog (2023); confirmed in your quote and submittal drawings.

## Frequently asked questions

### How can I tell molded from pultruded grating already installed?

Look at the bars and the top. Molded grating is a one-piece mesh with bars in both directions and usually a concave (meniscus) or quartz-grit top. Pultruded grating has parallel bearing bars joined by cross rods, commonly 6" (152 mm) on center, with a bonded grit surface.

### Do pultruded panels need a different support layout than molded panels?

Yes, in direction. Pultruded grating carries load along its bearing bars, which on standard stock panels run along the panel length, so that length must cross the supports. Molded grating is one piece with strength in both directions. See [how to install fiberglass grating](https://www.strongrate.us/resources/how-to-install-fiberglass-grating/).

### Can molded grating replace pultruded grating at the same span?

Only after checking its load table at that span and deflection limit. US makers market pultruded grating as about twice as stiff, so molded grating may need a greater depth or closer supports.

## Related pages
- [Fiberglass grating technical resources](https://www.strongrate.us/resources/): Index of fiberglass grating technical resources (load tables, sizes and weights, specifications, fire ratings, how-to guides, comparisons) and the standards they cite.
- [Molded fiberglass grating](https://www.strongrate.us/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.
- [Pultruded fiberglass grating](https://www.strongrate.us/pultruded-fiberglass-grating/): Strongrate pultruded fiberglass (FRP) grating: the 36 I-bar and T-bar types in the factory catalog with depth, open area and weight, the two DNV-listed models and their ASTM E84 results, resins, surfaces and how to order.
- [Fiberglass grating load tables](https://www.strongrate.us/resources/fiberglass-grating-load-tables/): The load tables in Strongrate’s catalog for each product, and how to read fiberglass grating load tables: uniform and line loads by span, deflection limits and safety factors.
- [Fiberglass vs steel grating](https://www.strongrate.us/compare/fiberglass-vs-steel-grating/): How fiberglass and steel grating compare on weight, corrosion, conductivity, temperature, upfront and 20-year cost and import rules, including when steel is the better choice.
- [Fiberglass grating clips](https://www.strongrate.us/accessories/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 FAQ](https://www.strongrate.us/faq/): Short answers to common buyer and engineer questions about fiberglass grating materials, loads, fire ratings, prices, import duty and buying factory-direct, each linking to its full page.

**Request a quote:** https://www.strongrate.us/request-quote/ · Order a sample: https://www.strongrate.us/samples/ — Not sure which fits your span? Send the span, design load and environment with your quote request. Quotes within 1 business day (US Central time); the reply confirms routing and next steps.

## Sources
- [Fibergrate FAQ (construction, surfaces, point-load tables, drilling)](https://www.fibergrate.com/resource-center/faq/) (accessed Oct 15, 2026)
- [Fibergrate pultruded grating page (glass content, stiffness)](https://www.fibergrate.com/products/pultruded-grating/) (accessed Oct 15, 2026)
- [Fibergrate molded FRP products brochure (resins, depths, panel sizes)](https://www.fibergrate.com/media/166803/molded-frp-products-brochure.pdf) (accessed Oct 15, 2026)
- [Fibergrate, Molded FRP Grating Details and Options (weights)](https://www.fibergrate.com/media/181504/molded-frp-grating-details-and-options.pdf) (accessed Oct 15, 2026)
- [Fibergrate industrial pultruded load tables (safety factors, creep and temperature notes)](https://www.fibergrate.com/media/181609/industrial-pultruded-load-tables.pdf) (accessed Oct 15, 2026)
- [McNichols molded fiberglass grating catalog (open area)](https://www.mcnichols.com/fiberglass-grating/molded) (accessed Oct 15, 2026)
- [McNichols MS-I-6010 pultruded grating spec page (cross-rod spacing)](https://www.mcnichols.com/fiberglass-grating/pultruded/fiberglass-fg-f1i60ysc) (accessed Oct 15, 2026)
- [Grating Pacific, Pultruded Sizes and Options (weights)](https://gratingpacific.com/wp-content/uploads/2019/10/Pultruded-Sizes-Options.pdf) (accessed Oct 15, 2026)
- [Grating Pacific pultruded grating page (open area)](https://gratingpacific.com/product/pultruded-fiberglass-grating/) (accessed Oct 15, 2026)
- [Grating Pacific high load capacity grating page (H-20 ratings)](https://gratingpacific.com/product/high-load-capacity-grating/) (accessed Oct 15, 2026)
- [Strongwell grating page (DURADEK depths and panel sizes)](https://www.strongwell.com/products/grating/) (accessed Oct 15, 2026)
- Strongwell blog, Pultruded Grating Performance at a Molded Grating Price (2017) (accessed Oct 15, 2026)
- [Direct Metals blog, Pultruded vs molded fiberglass grating (Jan 15, 2026)](https://www.directmetals.com/blog/pultruded-fiberglass-grating-vs-molded-fiberglass-grating-which-is-right-for-your-needs/) (accessed Oct 15, 2026)
- [American Grating molded FRP grating page (cut-outs)](https://www.americangrating.com/molded-frp-grating.aspx) (accessed Oct 15, 2026)
- [Bedford I 15-60 load notes (deflection limits)](https://bedfordreinforced.com/product/i-15-60/) (accessed Oct 15, 2026)
- [ACMA, 2nd edition ANSI/ACMA FGMC grating manual (2019)](https://acmanet.org/acma-releases-2nd-edition-national-standard-fiberglass-grating-manual/) (accessed Oct 15, 2026)
- [FRP vendor price guides (GTO FRP 2025 guide; Income Pultrusion guide, undated)](https://incomepultrusion.com/frp-grating-price-guide/) (accessed Oct 15, 2026)
- [U.S. Access Board, Guide to the ADA Standards, Chapter 3: Floor and Ground Surfaces](https://www.access-board.gov/ada/guides/chapter-3-floor-and-ground-surfaces/) (accessed Oct 15, 2026)
- [EPA, Build America, Buy America FAQs for manufacturers (Jun 2025)](https://www.epa.gov/system/files/documents/2025-06/baba-faqs-for-manufacturers.pdf) (accessed Oct 15, 2026)
- [DNV Type Approval Certificate TAF0000191 Rev. 1, including ASTM E84-19a results](https://www.shipserv.com/Shipserv/pages/profiles/261792/certifications/20241010142426209-DNV-GL-Certificate-GRATINGS-Strongrate.pdf) (accessed Oct 15, 2026)
- Strongrate product catalog “Your Best FRP Solution” (Sep 2023) (accessed Oct 17, 2026)
- [strongrate.com news item: molded grating, pultruded grating, structural shapes and hand lay-up products](https://www.strongrate.com/newsinfo-frpgrp-molded-grating-pultruded-grating-structural-shapes-and-hand-lay-up-products.html) (accessed Oct 15, 2026)

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Fiberglass (FRP) grating made by NANTONG STRONGRATE CO.,LTD in Nantong, China. Products ship from China. Made in Nantong, China · Ships from China · HTS 3925.90.