Fiberglass Grating
Molded and pultruded FRP/GRP grating in orthophthalic, isophthalic and vinyl ester resins — corrosion-free, non-conductive, non-sparking flooring for chemical, water and electro-technical plants.
Get a Quote Download CatalogMolded vs pultruded — specification matrix
Screenshot-ready. Every dimension below is a standard tooling size — custom spacings are cut to your drawing at no extra mold cost.
| Property | Molded (ISO), 38×38×38 | Pultruded I-beam 40×40 | Pultruded rectangular |
|---|---|---|---|
| Open area | ≈ 70% | ≈ 55% | ≈ 50% |
| Weight (kg/m²) | 12.5 | 13.8 | 15.2 |
| Resin options | Ortho / Iso / Vinyl | Iso / Vinyl | Iso / Vinyl |
| Bi-directional strength | Equal both ways | Strong on bearing axis | Strong on bearing axis |
| Panel size (m) | 1.22 × 3.66 / 1.22 × 4.88 | Any length to 6 | Any length to 6 |
| Best for | Cuts with cutouts, trenches | Long walkway runs | Heavy walkways, stairs |
Molded grating is the choice wherever cutouts and notches concentrate — its bi-directional grid loses no strength in any direction.
Choose your construction and material
Each family has its own load table, finish options and lead time.
Molded FRP Grating
Interlaced glass rovings in resin — equal strength both axes.
View series → Product FamilyPultruded FRP Grating
I-beam or rectangular profiles locked with rods — long spans, walkways.
View series → Product FamilyFRP Stair Treads
Grit-top treads, R12–R13 slip class, non-corroding.
View series → Product FamilyFRP Clips
Purpose-made FRP fasteners — no galvanic contact.
View series →Four material systems, one factory
Zinc thickness is measured per ASTM A123 (70–85 µm), salt-spray tested to 1,000 h. Stainless is pickled and passivated; FRP resin is matched to your chemical media.
| Material | Specification | Best For | QC Note |
|---|---|---|---|
| Carbon Steel, Hot-Dip Galvanized | Q235B / A36, zinc 70–85 µm per ASTM A123 | Walkways, platforms, trench covers, stair treads — the default choice | 1,000 h neutral salt-spray test before white rust |
| Stainless Steel 304 / 316L | AISI 304 (indoor / general chemical), 316L (marine / chloride) | Food processing, pharma, offshore, chemical plants | Passivated and pickled finish, 316L for >3% chloride media |
| Aluminum 6061-T6 | Mill or anodized finish, riveted or press-locked construction | Weight-critical platforms, water treatment, architectural meshes | ≈ 1/3 the weight of steel at comparable spans — cannot be hot-dip galvanized |
| FRP / Fiberglass (GRP) | Molded (isophthalic / vinyl ester) or pultruded profiles | Electrolytic areas, sewage plants, coastal platforms | Non-conductive, non-sparking, corrosion-free alternative to metal |
Load & deflection — pultruded I-beam 40×40, 40% glass
Values calculated to NAAMM MBG 531 with deflection limited to L/200. Need a stamped calculation sheet for your span? Ask in the quote form.
| Clear span (mm) | U-load (kN/m²) @ L/200 | C-load (kN) | Weight (kg/m²) |
|---|---|---|---|
| 600 | 18.4 | 7.9 | 13.8 |
| 900 | 8.2 | 5.3 | 13.8 |
| 1200 | 4.6 | 3.9 | 13.8 |
| 1500 | 2.9 | 2.9 | 13.8 |
FRP is elastic: it does not yield like steel. Deflection limits (L/150–L/200) govern design, not rupture — rupture margins exceed 4×.
Resin selection by chemical medium
Ambient, continuous immersion. VE = vinyl ester, ISO = isophthalic, ORTHO = orthophthalic. C = confirmed suitable, (C) = suitable with synthetic veil, X = not recommended.
| Medium | Concentration | ORTHO | ISO | VE | Notes |
|---|---|---|---|---|---|
| Sea water / salt spray | — | C | C | C | All grades pass; pick by budget |
| Municipal sewage (H₂S) | — | (C) | C | C | VE in headworks, ISO downstream |
| Chlorinated water (pool) | ≤ 5 ppm | X | C | C | ISO is the pool standard |
| Sulfuric acid | ≤ 30% | X | (C) | C | VE + veil above 30% |
| Hydrochloric acid | ≤ 20% | X | (C) | C | VE only above 10% |
| Sodium hydroxide (caustic) | ≤ 20% | X | (C) | C | VE standard for alkaline media |
| Bleach / hypochlorite | ≤ 10% | X | X | C | VE mandatory |
| Chromic / nitric plating baths | — | X | X | X | Ask — special resin systems |
| De-icing & fresh water | — | C | C | C | — |
Compiled from resin-supplier chemical charts (AOC, Reichhold). Confirm continuous temperature above 50 °C with our engineers.
Where fiberglass grating works hardest
Reference projects available per industry on request.
Water & wastewater treatment
Vinyl ester over H₂S and chlorine zones where metals fail in years.
Chemical & plating lines
Acid-proof gratings above tanks — resin matched per electrolyte.
Substations & electrochemical
Non-conductive — eliminates grounding and arc risk.
Offshore & marine
Sea-water-proof decks 50–70% lighter than steel.
Food & beverage floors
Iso resin with fine grit for washdown and barefoot zones.
Mining & refineries
Non-sparking where ignition risk rules out steel.
Send a drawing, receive a finished panel
Upload DXF or DWG with your RFQ — we return a dimensioned shop drawing for approval within 24 hours. No approval, no production.
In-house fabrication
- Cut-to-size from DXF / DWG drawings — band saw and plasma, ±2 mm tolerance
- Notching and cutouts for pipes, cable trays and manholes in any shape
- Banding (closed ends) in flat bar or checkered plate, toe plates to EN ISO 14122-3
- Curved and radial panels for tanks, towers and architectural projects
- Stair tread fabrication with welded or bolted carriers, nosing options
- Pre-assembly of clips, anchors and support steel into kit form for site speed
Everything is auditable
Third-party inspection (SGS/BV/TÜV) welcome at any stage. MTC per EN 10204 3.1 ships with every order by default.
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ASTM A36 — carbon structural steel bar and plate
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ASTM A123 — hot-dip galvanizing, 70–85 µm zinc coating on bearing bars
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ASTM A1011 / Q235B — flat bar feedstock with mill certificates
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NAAMM MBG 531 — load & deflection tables (uniform + concentrated load, L/200)
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EN 1090-1/-2 — structural steel execution, CE-marked assemblies
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ISO 9001:2015 — quality management system, audited annually
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MTC (EN 10204 3.1) material test certificate with every shipment
Ordering terms at a glance
1 pallet (approx. 20 m²) for stock sizes; custom sizes from 100 m²
15–25 days after drawing confirmation
20GP ≈ 26–28 t · 40HQ ≈ 26 t (varies with panel size)
FOB Shanghai / Ningbo · CIF & DDP available on request
T/T 30% deposit, L/C at sight for orders over USD 50,000
Fiberglass (FRP/GRP) grating replaces metal flooring wherever corrosion, electricity or spark risk makes steel the wrong answer. This page is built the way FRP buyers actually ask: which resin, molded or pultruded, and what happens over 20 years in your specific medium.
Fibergrate and the big distributors dominate the generic “fiberglass grating” term — so we do not fight them on their home page. We win on specific media, resin selection and pultruded spans. The resin matrix below is the core of that argument.
Resin selection: the first question every FRP buyer asks
The resin — not the glass — decides corrosion life. Orthophthalic (ortho) is the economical general-purpose resin for mild service. Isophthalic (iso) roughly doubles chemical resistance and is the default for water treatment and food. Vinyl ester is the heavy-duty resin: epoxy-based backbone, highest temperature and solvent resistance, standard for chlorinated and acidic media.
The complete per-medium matrix is in the table on this page. As a rule: municipal wastewater → iso or vinyl ester; chlorinated headworks → vinyl ester; plating acids at temperature → vinyl ester with synthetic veil; food washdown → iso with grit top.
Molded vs pultruded — the honest comparison
Molded grating carries equally in both directions, tolerates field cutouts, and costs less for small complex panels. Pultruded profiles carry 40–70% more per kg along the bearing axis, span longer, and produce straighter walkway runs — but only on one axis, so cutouts must respect the direction. Rule of thumb: platforms and trenches with penetrations → molded; long elevated walkways → pultruded I-beam.
Why FRP beats coated steel in the right places
Hot-dip zinc protects carbon steel until the first hard abrasion or cut edge — then rust runs. FRP has no coating to breach: the corrosion barrier is the material. Add 50–70% weight saving over steel (a two-person install becomes one), no grounding for electrical areas, no spark risk in explosive zones, and no paint maintenance over a 20+ year life. The trade: lower point-load tolerance, higher material cost per m², and creep under sustained heavy load — do not use FRP under forklifts.
Frequently asked questions
Molded or pultruded — which should I buy?
Which resin for a wastewater treatment plant?
How strong is FRP compared to steel grating?
Is FRP grating slippery?
Can it be cut on site?
Does FRP get brittle in UV or freezing weather?
How do I fix it?
Get a quote within 24 hours
Include panel size, load requirement and quantity — or just upload your drawing. Our engineers respond with a price and a load check.
Attach your file, then send the form — your email client will open with the details pre-filled. For files over 10 MB, email sales@yhsteelgrating.com directly.
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