FRP Grating Material Properties
ASTM E-84 tunnel test and self-extinguishing ratings
Most molded FRP products achieve flame spread index ≤ 25 (Class A/B per E-84) and are self-extinguishing per ASTM D-635.
| Resin System | Flame Spread (E-84) | Smoke / Behavior | Certification Notes |
|---|---|---|---|
| ZeAll VE (vinyl ester) | ≤ 25 | Self-extinguishing (D-635) | DNV GL TAF000003C; ABS Type Approval; SGS & Intertek tested |
| ZeAll FDA (food-grade iso) | ≤ 25 | Self-extinguishing (D-635) | USDA Approvable; antimicrobial |
| ZeAll ISO (improved iso) | ≤ 25 | Self-extinguishing (D-635) | SGS & Intertek tested |
| ZeAll FR (extra FR vinyl ester) | ≤ 10 | Self-extinguishing (D-635) | Lowest flame spread offered; SGS & Intertek tested |
| ELS (low-smoke) | ≤ 25 | Smoke developed ≤ 100; fuel contribution = 0 | DNV GL TAF000003C; SGS & Intertek tested |
| ZeAll Super VE (custom VE) | Non-FR unless specified | Up to 400°F (204°C) service | Solvents / oxidizers / ClO₂ / NaOCl |
| ZeAllgrate Molded VE / ISO / FF | ≤ 25 | Smoke developed ≤ 450 (Class A) | Flame impinged on top AND bottom; ABS Class ships |
ZeAll FR vinyl ester offers the lowest flame spread (≤10). ELS is a low-smoke, zero-fuel-contribution grade. HLC molded grating: E-84 ≤ 25, Class 1 fire rating. Source: Industry reference Molded Catalog p.2,7; ZeAllgrate Molded Metric Brochure p.2.
Non-conductive grating with optional conductive (anti-static) surface
Fiberglass grating is electrically non-conductive by nature — a key safety benefit over steel in live electrical areas.
Baseline Insulation
FRP grating provides inherent electrical insulation. Arc resistance 120 s; dielectric strength 35 kV/in lengthwise; dielectric constant 5 @ 60 Hz (pultruded structural shapes).
Conductive Surface (NFPA 77)
For flammable/vapour atmospheres, specify a conductive surface: average surface resistivity 2.5×10³ – 1×10⁶ Ω per lineal foot; average resistance to ground < 10⁸ Ω.
| Conductive Surface Parameter | Value (per NFPA 77, 2000 ed.) |
|---|---|
| Average surface resistivity | 2.5 × 10³ – 1 × 10⁶ Ω / lineal foot |
| Average resistance to ground | < 10⁸ Ω |
| Grounding attachments | Recommend ≥ 4 ground points, one at each corner |
Source: Industry reference Molded Catalog p.2, p.8; Structural Shapes Brochure p.7.
Low thermal conductivity and continuous-use temperature limits
FRP has low thermal conductivity — comfortable to the touch and an insulator against process heat.
| Resin / System | Max Continuous Service Temperature | Equivalent |
|---|---|---|
| ZeAll VE & pultruded VEFR | 180°F | 82°C |
| ZeAll ISO, ZeAll FDA, ZeAll FR & pultruded ISOFR | 150°F | 66°C |
| ZeAll Super VE (custom formulations) | Up to 400°F | 204°C |
ZeAll Super VE custom resins suit elevated-temperature service (solvents, oxidizers, ClO₂, NaOCl, liquid desiccants); they are non-fire-retardant unless specified. Source: Industry reference Molded Catalog p.2,7,19.
ASTM D7290 — characteristic (minimum) values
For engineering design, use characteristic minimum values, not "typical" averages.
Characteristic Value
Per ASTM D7290, the characteristic design value is typically the mean minus 2–3 standard deviations — a lower-bound value, not a mean.
Engineering Use
Industry reference recommends minimum or characteristic values for design. "Typical" values are not recommended for use by professional engineers; they describe material behaviour, not allowables.
Source: Industry reference ZeAllgrate Molded Metric Brochure, p.4.
Structural Shapes pultruded structural shapes (ISOFR / VEFR)
L.W. = lengthwise (along pultrusion / bearing bars); C.W. = crosswise. These are typical coupon values for pultruded structural profiles.
| Property | Standard | Lengthwise (L.W.) | Crosswise (C.W.) |
|---|---|---|---|
| Tensile stress | ASTM D-638 | 30,000 psi | 7,000 psi |
| Tensile modulus | ASTM D-638 | 2.5 × 10⁶ psi | 0.8 × 10⁶ psi |
| Compressive stress | ASTM D-695 | 30,000 psi | 15,000 psi |
| Compressive modulus | ASTM D-695 | 2.5 × 10⁶ psi | 1.0 × 10⁶ psi |
| Flexural stress | ASTM D-790 | 30,000 psi | 10,000 psi |
| Flexural modulus | ASTM D-790 | 1.8 × 10⁶ psi | 0.8 × 10⁶ psi |
| Modulus of elasticity (full section) | — | 2.8 × 10⁶ psi | — |
| Shear modulus | — | 0.450 × 10⁶ psi | — |
| Short beam shear | ASTM D-2344 | 4,500 psi | — |
| Punch shear | ASTM D-732 | 10,000 psi | — |
| Notched Izod impact | ASTM D-256 | 25 ft-lb/in | 4 ft-lb/in |
Physical & Electrical Coupon Properties
| Property | Standard | Value |
|---|---|---|
| Barcol hardness | ASTM D-495 | 45 |
| 24-hour water absorption | ASTM D-570 | 0.45% max |
| Density | ASTM D-792 | 0.062–0.070 lb/in³ (≈1.72–1.94 g/cm³) |
| Coefficient of thermal expansion, lengthwise | ASTM D-696 | 8 × 10⁻⁶ in/in/°C (≈14.4 × 10⁻⁶ /°F) |
| Property | Standard | Value |
|---|---|---|
| Arc resistance | ASTM D-495 | 120 seconds |
| Dielectric strength | ASTM D-149 | 35 kV/in (lengthwise); 200 volts/mil (parallel to fiber) |
| Dielectric constant | ASTM D-150 | 5 @ 60 Hz |
Source: Industry reference Structural Shapes Brochure (Part No. 883102), p.7 "Typical Coupon Properties".
Industry reference — per ft of width (in² / in⁴ / in³)
A = cross-sectional area, I = moment of inertia, S = section modulus.
| Style (depth × mesh) | A (in²) | I (in⁴) | S (in³) |
|---|---|---|---|
| 5/8" × 1"×4" rect | 2.11 | 0.07 | 0.22 |
| 1" × 3/4"×4" (Ecograte62) | 3.58 | 0.298 | 0.573 |
| 1" × 1"×4" rect | 2.57 | 0.22 | 0.43 |
| 1" × 1-1/2" sq | 1.71 | 0.14 | 0.29 |
| 1" × 2" sq | 1.27 | 0.11 | 0.21 |
| 1-1/4" × 1-1/2" sq | 2.16 | 0.32 | 0.48 |
| 1-1/2" × 1-1/2" sq | 2.85 | 0.51 | 0.65 |
| 2" × 2" sq | 2.88 | 0.96 | 0.94 |
| HLC 1-1/2" × 1"×2" | 7.45 | 1.39 | 1.80 |
| HLC 2" × 1"×2" | 10.26 | 3.4 | 3.27 |
Source: Industry reference Molded Grating Catalog, p.5–6, p.12–13.
ZeAllgrate Molded — per m of width (mm² / mm⁴ / mm³)
Standard panel matrix with open area and weight.
| Thickness × Mesh | A per m (mm²) | I per m (mm⁴) | S per m (mm³) | Open | Weight (kg/m²) |
|---|---|---|---|---|---|
| 25.4 mm × 38.1 sq | 3.62 × 10³ | 1.91 × 10⁵ | 1.56 × 10⁴ | 70% | 12.7 |
| 25.4 mm × 25.4×101.6 rect | 5.44 × 10³ | 3.00 × 10⁵ | 2.31 × 10⁴ | 69% | 13.7 |
| 38.1 mm × 38.1 sq | 6.03 × 10³ | 6.96 × 10⁵ | 3.49 × 10⁴ | 70% | 18.6 |
| 38.1 mm × Mini-Mesh | 7.98 × 10³ | 9.75 × 10⁵ | 4.26 × 10⁴ | 44% | 22.0 |
| 50.8 mm × 50.8 sq | 6.09 × 10³ | 13.11 × 10⁵ | 5.05 × 10⁴ | 72% | 19.5 |
25.4 mm × 25.4×101.6 rectangular mesh is grit-surface only. Mini-Mesh meets ADA (12.7 mm open mesh + slip resistance, regardless of travel direction). Source: Industry reference ZeAllgrate Molded Metric Brochure, p.3.
What these data are — and what to verify on your COA
Pultruded coupon values: the mechanical properties above (tensile, compressive, flexural, shear, impact) are typical coupon values for pultruded structural shapes in ISOFR/VEFR resins, transcribed from the Industry reference Structural Shapes brochure. They describe unidirectional pultruded performance.
Molded grating differs: molded grating contains roughly 33% glass (vs. ~70% for pultruded) and is bi-directional, so its specific laminate tensile / flexural / compressive numbers are lower and not interchangeable with the Structural Shapes coupon table. The molded catalogs publish section stiffness (A, I, S, EI) and load/span tables, not a dedicated coupon property sheet.
ZeAllgrate COA: for your exact resin, thickness and mesh, the controlling tensile (ASTM D638), flexural (ASTM D790), compressive (ASTM D695), specific gravity (ASTM D792) and water absorption (ASTM D570) values are supplied on the material certificate (COA) shipped with each batch. Share your resin system and we will provide the matching certificate and test report before order.
- Industry reference Fiberglass Molded Grating & Products Catalog — fire ratings, electrical, thermal, molded section properties.
- Industry reference ZeAllgrate Molded Metric Brochure — ASTM D7290 method, metric section matrix.
- Industry reference Structural Shapes Brochure (Part No. 883102), p.7 Typical Coupon Properties. PDF
- Industry reference ZeAll Pultruded Industrial Grating — Load Tables (resin systems VEFR / ISOFR). PDF
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