Fiberglass Grating Specification (Guide Spec)

1. Section includes: [molded fiberglass grating] [pultruded fiberglass grating] [fiberglass stair treads] [hold-down clips and fasteners] [field cutting and edge sealing].
2. Related work specified elsewhere: [structural supports] [guardrails and handrails] [stairs and ladders].

• ASTM E84: surface burning characteristics (flame spread index and smoke-developed index).
• ASTM D635: burning behavior of plastics in a horizontal position.
• [UL 94: flammability of plastic materials.]
• ANSI/ACMA FGMC FRP Composites Grating Manual, 2nd edition (2019).
• [ASTM D638, D790 and D2344: tensile, flexural and short-beam shear properties, for pultruded bars.]
• [ASTM D4060: abrasion resistance, for grit surfaces.]
• OSHA 29 CFR 1910.22, 1910.23, 1910.25 and 1910.29.
• 2010 ADA Standards for Accessible Design, §302.3.
• International Building Code, Chapter 26 (Section 2612) and Chapter 8 [edition adopted by the jurisdiction].
• [ASTM F3059: fire integrity of FRP grating on vessels and offshore installations.]
• [AASHTO LRFD Guide Specifications for the Design of FRP Pedestrian Bridges, 2nd edition (2025).]
• [CSA S806:26: design and construction of building structures with fiber-reinforced polymers, for Canadian projects.]

1. Walking-working surfaces: support the maximum intended load (OSHA 29 CFR 1910.22(b)).
2. Design load: [60 psf (2.9 kPa) uniform live load per ASCE 7] [100 psf (4.8 kPa) uniform or 300 lb (1.3 kN) concentrated] [as shown on the drawings].
3. Deflection at design load: [not more than 1/4" (6.4 mm)] [not more than 3/8" (9.5 mm) or L/120, whichever is less].
4. Supporting members: deflection not more than L/180 [coordinate with the structural design].
5. Stair treads: [100 psf (4.8 kPa) uniform or 300 lb (1.3 kN) concentrated over 4 in² (2581 mm²)]. Stairs: not less than five times the normal live load and not less than a 1,000 lb (4.4 kN) concentrated load (OSHA 29 CFR 1910.25).
6. Impact or dynamic loads: [use half the tabulated capacity] [double the design load] when selecting grating from the load tables.
7. Accessible routes: openings shall not allow passage of a 1/2" (13 mm) diameter sphere; elongated openings perpendicular to the dominant direction of travel (2010 ADA Standards §302.3).
8. Surface burning: flame spread index of [25] or less per ASTM E84, tested on the finished grating [and smoke-developed index of 450 or less where Class A interior finish is required].
9. [Self-extinguishing per ASTM D635; grating shall not burn past the 1" (25 mm) reference mark.]
10. [Flammability rating of V-0 per UL 94.]

Specifier’s note: choose loads and deflection limits with the project engineer; typical pedestrian loads in load-table notes are 50–65 psf (2.4–3.1 kPa). Require fire data on the finished grating, not the resin alone. See fiberglass grating load tables and ASTM E84 Class 1 fire rating.

1. Product data for each grating type: resin, color, surface, depth, mesh or bar profile, and open area.
2. Load and deflection tables for each product at the spans shown, stating the test method, safety factor and deflection basis.
3. Corrosion-resistance tables for the resin proposed [for the chemicals listed in the schedule].
4. ASTM E84 test reports on the finished grating in the proposed resin, identifying the laboratory, report number and test date. Data from tests on the resin alone is not acceptable.
5. Certificates of compliance [and type-approval certificates for marine and offshore use].
6. Shop drawings: panel layout, bearing-bar direction, support locations, cutouts and clip locations.
7. Samples of each type of product.
8. Warranty.

1. Load tables: based on tests per the ANSI/ACMA FGMC grating manual [or another method approved by the engineer].
2. [Maximum recommended loads based on acoustic emission testing; panel stiffness not more than 2.5% below published values.]
3. [Manufacturer’s quality-system certification: ______.]
4. Fire test reports: issued by a third-party laboratory for the product and resin supplied.

1. Store resin and edge-sealing kits at 70–85°F (21–29°C) [or as the kit supplier instructs].
2. [Marine and offshore projects under a type approval: each grating marked with the brand and fire rating, and the manufacturer’s manual supplied with the product.]

1. Manufacturer’s [1-year] [3-year] limited warranty against defects in materials and workmanship, starting at [delivery] [substantial completion].

Specifier’s note: published US grating warranties run from 1 to 3 years. Strongrate terms are on terms, warranty and returns.

• Option A (no domestic-content requirement): no restriction on country of manufacture. The submittals shall state the country of manufacture.
• Option B (Build America, Buy America applies): fiberglass grating, treads and other plastic or polymer-based composite products shall be produced in the United States, with all manufacturing processes in the United States, per 2 CFR part 184.

Specifier’s note: use Option B on infrastructure projects that receive federal financial assistance covered by BABA. Strongrate grating is made in Nantong, China, and does not qualify under Option B. Privately funded industrial, commercial and marine projects are not subject to BABA, though the owner may still require US manufacture. See Buy America (BABA) and imported FRP grating.

1. Basis of design: [manufacturer and product line].
2. [Nantong Strongrate Co., Ltd., Nantong, Jiangsu, China (products ship from China): products for which the submittals in Article 1.4 meet this section.]
3. Substitutions: [per Division 01]; submit the data listed in Article 1.4.

1. Construction: one-piece molded panels with load-bearing bars in both directions.
2. Resin: [isophthalic polyester] [vinyl ester] [fire-retardant polyester] [food-grade isophthalic with antimicrobial additive] [______].
3. Glass content: [not more than 35% by weight].
4. Depth: [1" (25 mm)] [1-1/2" (38 mm)] [2" (51 mm)]. Mesh: [1-1/2" × 1-1/2" (38 × 38 mm) square] [______].
5. Tolerances: depth and mesh ±1/16" (1.6 mm); fillet radius at bar intersections not less than 1/16" (1.6 mm); top reinforcement not more than 1/8" (3.2 mm) below the top surface.
6. Surface: [concave (meniscus)] [applied quartz grit] [fine grit for barefoot areas].
7. Color: [yellow] [dark gray] [light gray] [green] [______].
8. Products exposed to weather shall contain an ultraviolet inhibitor.
9. Fire performance: as specified in Article 1.3.

Specifier’s note: Strongrate’s catalog lists 30–35% glass by weight for molded grating, with UV inhibitors in the resin, and concave, gritted, smooth and solid-cover surfaces (materials below).

1. Construction: pultruded [I-bar] [T-bar] bearing bars joined by cross rods at [6" (152 mm)] on center.
2. Bar depth and open area: [1" (25 mm) I-bar] [1-1/2" (38 mm) I-bar] at [40%] [60%] open; [2" (51 mm) T-bar] at [33%] [50%] open.
3. Minimum bar properties: tensile and flexural strength 30,000 psi (207 MPa); flexural modulus 1.8 × 10⁶ psi (12.4 GPa); short-beam shear 4,500 psi (31 MPa); tested per ASTM D638, D790 and D2344.
4. Grit surface: wear index below 1.0 per ASTM D4060, before and after 750 hours of UV exposure.
5. Resin, color, ultraviolet inhibitor and fire performance: as specified for molded grating.
6. Drilled holes and cut ends: sealed as specified in Article 2.5.

Specifier’s note: Strongrate’s catalog lists 60–65% glass content for pultruded grating, and its DNV-listed models I 6015 at 1-1/2" (38 mm) deep, 60% open, and T5020 at 2" (50 mm) deep, 50% open. See pultruded fiberglass grating.

1. Treads: [molded] [pultruded] fiberglass grating with a gritted nosing [in a contrasting color], sized to the stringers shown.
2. Load: as specified in Article 1.3.
3. Stair geometry (OSHA 29 CFR 1910.25, standard stairs): angle 30° to 50°; risers not more than 9-1/2" (241 mm); treads not less than 9-1/2" (241 mm) deep; width not less than 22" (559 mm) [verify against the building code].

Specifier’s note: Strongrate’s catalog lists molded tread covers with a gritted nosing in a contrasting color and pultruded grating treads with a gritted tube nosing. See fiberglass stair treads.

1. Hold-down clips: Type 316 stainless steel, spaced not more than 4 ft (1.22 m) apart, with not fewer than four clips per piece of grating [or more where the manufacturer recommends].
2. Cut edges, cutouts and drilled holes: sealed with [vinyl ester] [catalyzed] resin compatible with the grating resin.
3. [Guardrails where required: top rail 42" ± 3" (1067 ± 76 mm) above the walking surface, withstanding a 200 lb (0.9 kN) force; toeboards not less than 3-1/2" (89 mm) high (OSHA 29 CFR 1910.29).]

Specifier’s note: Strongrate’s catalog lists six clip types (L, M, C, W, J and G), made mainly of stainless steel. See fiberglass grating clips.

1. Verify that supports are level and that support spacing does not exceed the spans used to select the grating from the load tables.
2. Report deviations in writing before starting installation.

1. Lay panels with the bearing bars spanning between supports. [Pultruded stock panels: bearing bars run parallel to the panel length.]
2. Provide not less than [1-1/2" (38 mm)] of bearing on each support.
3. Fasten with hold-down clips as specified in Article 2.5.
4. On accessible routes, orient elongated openings perpendicular to the dominant direction of travel.
5. Cut with carbide or diamond tooling; seal all cut edges, cutouts and drilled holes with resin as specified in Article 2.5.
6. Openings cut in panels: provide added support [where the opening exceeds ______] [as the manufacturer recommends].

See how to install fiberglass grating and how to cut fiberglass grating.

1. Before acceptance, inspect for loose or missing clips, unsealed cuts and damaged panels, and correct them.
2. Owner: inspect walking-working surfaces regularly and have hazardous conditions corrected or repaired by a qualified person (OSHA 29 CFR 1910.22(d)).