Molded Grating — Complete Specification Matrix
Compression-Molded FRP Grating
Glass roving and continuous strand are laid in both directions and compression-molded with thermoset resin, producing a truly bi-directional panel.
Compression molding
Fibrous glass is pre-formed and molded under heat and pressure in a single tool, locking the bi-directional grid into a rigid, integral panel — no secondary bonding.
Bi-directional strength
Load is carried in both panel directions, so molded grating performs reliably regardless of bar orientation relative to the span.
Glass content ≈ 33%
Typical glass loading is 33% ± 3% by weight (resin-rich, corrosion-dominant laminate), vs. ~70% for pultruded grating.
| Standard panel size | 1220 × 3660 mm (≈ 4' × 12') — most stocked |
| Other standard panels | 1000 × 3000 mm · 1220 × 2440 mm · cut-to-size available |
| Standard meshes | 38 × 38 mm (rectangular / square) · 19 × 19 mm mini-mesh · 25 × 100 mm rectangular |
Standard molded configurations — section properties per metre of width
I = moment of inertia per m width; Z = section modulus per m width. Panel weight based on 1220 × 3660 mm (4.465 m²). Spans/loads are indicative for pedestrian service.
| Thickness | Mesh | Open Area | Weight (kg/m²) | Panel Weight (kg, 1220×3660) | I (cm⁴/m) | Z (cm³/m) | Max Span @ L/200 (mm) | Max Uniform Load @ 1 m span (kN/m²) |
|---|---|---|---|---|---|---|---|---|
| 25 mm | 38 × 38 mm | 70% | 12.7 | 56.7 | 19.1 | 15.6 | ≈ 900 | ≈ 8.5 |
| 25 mm | 19 × 19 mm (mini-mesh) | 50% | 14.5 | 64.7 | 33.0 | 25.0 | ≈ 850 | ≈ 9.0 |
| 30 mm | 38 × 38 mm | 70% | 15.0 | 67.0 | 34.0 | 22.0 | ≈ 1050 | ≈ 13 |
| 38 mm | 38 × 38 mm | 70% | 18.6 | 83.0 | 69.6 | 34.9 | ≈ 1250 | ≈ 23.5 |
| 38 mm | 19 × 19 mm (mini-mesh) | 44% | 22.0 | 98.2 | 97.5 | 42.6 | ≈ 1200 | ≈ 26 |
| 40 mm | 38 × 38 mm | 70% | 19.5 | 87.1 | 80.0 | 40.0 | ≈ 1300 | ≈ 27 |
| 50 mm | 38 × 38 mm | 70% | 21.5 | 96.0 | 130.0 | 52.0 | ≈ 1500 | ≈ 33 |
| 50 mm | 19 × 19 mm (mini-mesh) | 45% | 28.0 | 125.0 | 180.0 | 72.0 | ≈ 1450 | ≈ 36 |
Molded section properties (I, Z, weight, open area) are consistent with industry molded-grating technical catalogs (manufacturer data); spans and uniform loads are indicative and derived from manufacturer load tables for pedestrian live load. Verify against certified load/span charts for your exact resin and surface. Source: Industry molded-grating technical catalogs (manufacturer data); ZeAllgrate (ACMA) design guidelines; ASTM D638 / D790 / D695 / D792 / D570 / E84.
Typical laminate values per ASTM test methods
Values are typical production-panel properties. Use characteristic (minimum) design values per ASTM D7290 for engineering design.
| Property | Test Method | Typical Value |
|---|---|---|
| Density | ASTM D792 | 1.8 – 2.0 g/cm³ (≈ 0.065 – 0.072 lb/in³) |
| Glass content | Combustion / ignition loss | 33% ± 3% by weight |
| Tensile strength (laminate) | ASTM D638 | ≈ 80 – 100 MPa (typical) |
| Flexural strength (laminate) | ASTM D790 | ≈ 150 – 200 MPa (typical) |
| Flexural modulus | ASTM D790 | ≈ 10,000 – 12,000 MPa (typical) |
| Compressive strength | ASTM D695 | ≈ 150 – 200 MPa (typical) |
| Water absorption (24 h) | ASTM D570 | < 0.5% |
| Barcol hardness | ASTM D2583 | > 40 |
| Thermal conductivity | ASTM C177 / ISO 8302 | 0.3 – 0.5 W/(m·K) |
| Coeff. of thermal expansion (in-plane) | ASTM D696 | ≈ 12 × 10⁻⁶ /°C |
| Coeff. of thermal expansion (through-thickness) | ASTM D696 | ≈ 80 × 10⁻⁶ /°C |
| Dielectric strength | ASTM D149 | > 10 kV/mm (inherent insulation) |
Tensile/flexural/compressive values are typical laminate values for molded FRP (bi-directional, ~33% glass) and are not interchangeable with unidirectional pultruded coupon data. Exact values supplied on the batch COA. Source: Industry molded-grating technical catalogs (manufacturer data); ZeAllgrate (ACMA) design guidelines; ASTM D638 / D790 / D695 / D792 / D570 / E84.
Match the resin to the media, concentration and service temperature
Tg is the glass-transition temperature; max continuous service temperature is the long-term design limit.
| Resin System | Tg (typical) | Max Service Temp. | Chemical Resistance Summary | Fire Performance | Typical Application |
|---|---|---|---|---|---|
| ZeAll Ortho (general purpose) | ≈ 80 – 100 °C Tg | ≈ 60 °C | Good general/corrosion; water, mild acids/bases | Self-extinguishing (ASTM D635); E84 ≤ 25 typical | General walkways, sewage, water treatment |
| ZeAll ISO (corrosion grade) | ≈ 110 – 120 °C Tg | ≈ 80 °C | Improved acid/alkali resistance over ortho | Self-extinguishing; E84 ≤ 25 | Chemical plants, plating, scrubbers |
| ZeAll VE (vinyl ester) | ≈ 130 – 150 °C Tg | ≈ 90 °C | Excellent — acids, solvents, oxidizers, bleach | Self-extinguishing; E84 ≤ 25 | Harsh process areas, pulp & paper, offshore |
| ZeAll FR (fire-retardant VE) | ≈ 130 – 150 °C Tg | ≈ 90 °C | Excellent corrosion + low flame spread / low smoke | E84 Class A (≤ 25, low smoke); USCG / ABS options | Marine, metro, enclosed/ventilated buildings |
| Phenolic | ≈ 180 °C+ Tg | ≈ 120 °C (long-term) | Excellent fire/smoke performance; limited chemical range | Very low smoke, self-extinguishing, no dripping | Public transport, tunnels, high-fire-risk zones |
Fire-retardant grades achieve ASTM E84 flame spread index ≤ 25 (Class A/B) and are self-extinguishing per ASTM D635; low-smoke and marine approvals (USCG, ABS, DNV) available on request. Source: Industry molded-grating technical catalogs (manufacturer data); ZeAllgrate (ACMA) design guidelines; ASTM D638 / D790 / D695 / D792 / D570 / E84.
Coefficient of friction (COF) — wet and dry
COF values are indicative; grit-top provides the highest grip in wet/oily service.
| Surface | COF (dry / wet) | Open-Area Effect | Typical Use |
|---|---|---|---|
| Concave (meniscus, standard) | 0.60 – 0.70 dry / 0.45 – 0.55 wet | No loss of open area | Standard molded profile — general industrial walkways |
| Convex | 0.55 – 0.65 dry / 0.40 – 0.50 wet | No loss of open area | Improved drainage, easy cleaning |
| Grit-top (silica carbide / quartz) | 0.75 – 0.85 dry / 0.55 – 0.70 wet | Slightly reduced open area | Wet, oily and chemical process areas — best grip |
| Smooth | 0.30 – 0.40 dry / 0.15 – 0.25 wet | No loss of open area | Light pedestrian / aesthetic; not for wet service |
Standard stock colors and fabrication tolerances
Standard colors: Green (RAL 6010) · Gray (RAL 7047) · Yellow (RAL 1003) · Red · Blue · Black. Custom Pantone / RAL matching available on request.
| Feature | Tolerance | Note |
|---|---|---|
| Panel thickness | ± 1.0 mm | Measured at the bar centre |
| Panel dimensions (1220 / 3660 mm) | ± 3.0 mm | Length and width |
| Squareness (diagonal) | ≤ 3.0 mm | Difference of two diagonals |
| Flatness (warpage) | ≤ 3 mm per 1000 mm | Over support span |
| Cut / drilled holes | Ø + 1.0 mm | Radius corners to avoid stress concentration |
Fastener type by grating thickness
Fasten every panel at every support intersection; minimum 4 hold-down clips per panel.
| Grating | Recommended Clip | Material Options | Clips per Panel | Spacing |
|---|---|---|---|---|
| 25 mm molded | G-Clip (standard) | SS304 / SS316 / galvanized | ≈ 6 – 8 per panel | ≈ 300 mm from edge; ≤ 1200 mm c/c at each support |
| 30 mm molded | G-Clip | SS304 / SS316 / galvanized | ≈ 6 – 8 per panel | ≤ 1200 mm c/c at each support |
| 38 mm molded | G-Clip or M-Clip | SS304 / SS316 / galvanized | ≈ 6 – 8 per panel | ≤ 1200 mm c/c at each support |
| 50 mm molded | M-Clip (heavy-duty) | SS304 / SS316 / galvanized | ≈ 8 per panel | ≤ 1200 mm c/c; minimum 4 clips per panel |
| Pultruded 40 – 60 mm | G-Clip / saddle clip | SS304 / SS316 | ≈ 4 – 6 per panel | At every bearing-bar / support intersection |
G-Clip for standard molded thicknesses; M-Clip for 50 mm heavy panels. In coastal/marine or chemical service, specify SS316 over galvanized to avoid galvanic corrosion. See the Accessories Catalog for full fastener selection.
- Industry molded-grating technical catalogs (manufacturer data) — molded load/span, section matrix, fire & thermal data.
- ZeAllgrate (ACMA) Guidelines for the Engineer / Designer — pedestrian design criteria, deflection limits, ASTM D7290 characteristic method.
- ASTM test methods: D638 (tensile), D790 (flexural), D695 (compressive), D792 (density), D570 (water absorption), E84 (surface burning).
Engineers should specify from certified load/span charts for the exact resin, thickness and surface. ZeAllgrate supplies load test reports and material certificates (COA) with every shipment. Contact [email protected] for project-specific data.
Approved by Industry Bodies, Tested to International Standards
Every ZeAllgrate shipment is backed by documented quality systems, marine approvals and independent third-party verification.
ISO 9001:2015
Certified quality management system — since 2004.
DNV & ABS Marine
Marine-grade grating for offshore platforms and vessel decks.
SGS & Intertek
Independent third-party inspection and load testing on request.
OSHA 1910.23
Handrail systems load-tested to US federal requirements.
Material certificates, COA, ASTM test reports and compliance documentation supplied with every order. View certifications →
Need a Certified Specification for Your Project?
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