Grating is normally priced per tonne of steel, then processing, galvanizing and packing are added. The weight comes from the bearing-bar size and pitch; the construction (welded vs press-locked) sets the labour; hot-dip galvanizing to EN ISO 1461 (70-85 µm) and any cutouts or stair treads add the final slices. This guide explains the structure, not a market price.
Because the material cost tracks steel mass, the first thing a quotation reflects is how heavy the panel is.
A grating panel is a grid of bearing bars (running in the span direction) and cross bars. Its weight per square metre is set by the bearing-bar height and thickness, the bearing-bar pitch, and the cross-bar pitch. Heavier bars and tighter pitch mean more steel, so the panel costs more even before any coating is applied.
The standard envelope we quote against is on the steel grating specifications page: bearing bars 25×3 to 50×5 mm, bearing-bar pitch 30 / 33 / 40 / 60 mm, cross-bar pitch 50 / 100 mm, hot-dip galvanized to EN ISO 1461.
A common heavy-duty specification. Estimate the steel mass per square metre from the bar geometry.
| Component | Estimated mass |
|---|---|
| Bearing bars (50×5 @ 30 mm) | ≈ 65 kg/m² |
| Cross bars (6 mm @ 100 mm) | ≈ 2-3 kg/m² |
| Total panel | ≈ 67-68 kg/m² |
This is an illustrative estimate using nominal geometry; real weight varies slightly with banded edges and tolerance. The lesson is the lever: moving from 40×5 to 50×5 bars, or from 40 mm to 30 mm pitch, adds a predictable amount of steel — and therefore cost — you can see in the quote.
Once the steel mass is known, the construction method and the coating set the processing and finishing cost.
Welded vs press-locked. Welded grating joins every intersection by resistance welding — fast and the lowest-cost route for load-bearing floors. Press-locked grating presses cross bars into notched bearing bars for a smooth, weld-free surface, a slower process that carries a premium and is chosen for architectural or pedestrian-facing decks.
Hot-dip galvanizing. Finishing to EN ISO 1461 delivers a zinc coating of 70-85 µm on grating sections — the corrosion protection that lets outdoor grating survive for decades. It is charged largely by the tonne of steel dipped, so it scales with the weight you already calculated in Step 2. For most outdoor and industrial projects it is the cheaper option compared with early replacement of an unprotected floor.
The same area, three ways — showing how each decision changes the cost structure.
| Choice | Effect on weight | Effect on processing |
|---|---|---|
| 40×5 @ 40 mm, welded, HDG | Lower | Lowest cost route |
| 50×5 @ 30 mm, welded, HDG | Higher | Standard + more zinc |
| 50×5 @ 30 mm, press-locked, HDG | Higher | Premium processing |
None of these rows carries a price — the absolute numbers float with the steel index. What is stable is the ordering: tighter pitch and heavier bars raise weight; press-locked raises processing; galvanizing scales with weight. A complete quote should let you see each of these lines.
Because the raw material cost is driven by steel mass, and two panels of the same area can have very different weights depending on bearing-bar size, pitch and cross-bar pitch. Quoting per tonne makes the material element transparent; the fabricator then adds processing, galvanizing and packing. Per-square-metre pricing is still useful for budgeting once the specification is fixed.
Galvanizing is charged largely by the tonne of steel processed, since the panel is dipped in a zinc bath sized to the load. It is a meaningful but predictable addition, and it is what delivers the 70-85 micrometre coating required by EN ISO 1461. Compared with the cost of replacing corroded grating early, the galvanizing step is almost always the cheaper option for outdoor service.
Typically yes, for the same bar size. Press-locked construction presses cross bars into notched bearing bars under high pressure, a slower process than resistance welding, and it is chosen for a smooth, weld-free architectural surface. Welded grating remains the lowest-cost route for most load-bearing industrial floors, which is why it dominates plant platforms and trench covers.