Platform steps — also referred to as grating stair treads, steel grating steps, stair tread gratings or industrial stair treads — are purpose-designed stair tread elements manufactured from steel grating with an integrated bent nosing edge (Antrittskante) that defines the front edge of each step. ULAMEX supplies grating stair treads manufactured by WEMA, hot-dip galvanized per DIN EN ISO 1461, designed for industrial staircases, access platforms, external fire escapes and all permanent means of access where durability, slip resistance and low maintenance are essential requirements. Combined with platform gratings, these stair treads form complete industrial access systems for multi-level installations in manufacturing plants, power stations, chemical works, wastewater treatment facilities and infrastructure projects across Europe.
Design and Nosing Construction
The defining feature of a grating stair tread is the bent nosing edge — the front edge of the tread is bent downward at approximately 25–35° to create a visible and tactile step indicator. This nosing serves multiple critical functions:
- Visual step identification — the bent nosing creates a clear visual contrast at the front edge of each tread, enabling users to identify step positions even in low-light conditions. This is a fundamental safety requirement in industrial environments where staircase lighting may be limited or inconsistent.
- Tactile edge feedback — the change in surface angle provides tactile feedback through footwear, alerting users to the step edge position and reducing the risk of overstepping, particularly during descent.
- Structural stiffening — the bent nosing edge acts as a structural flange, significantly increasing the tread’s resistance to deflection under load. This allows the tread to span between staircase stringers without intermediate support, even under concentrated loads from personnel carrying tools and equipment.
- Water and debris shedding — the downward angle of the nosing encourages water and loose debris to run off the tread front edge rather than pooling on the walking surface, contributing to maintained slip resistance in wet conditions.
The tread body is constructed from standard grating mesh — bearing bars running perpendicular to the staircase stringers (in the span direction) with cross bars providing lateral stability. The grating construction ensures that the stair tread shares all the inherent advantages of steel grating flooring: free drainage, no standing water accumulation, light and air passage, and resistance to dust and debris build-up.
Standard Dimensions and Sizes
ULAMEX stocks grating stair treads in three standard widths (measured parallel to the staircase stringers, i.e., the usable walking width of the staircase) and three standard depths (measured perpendicular to the stringers, i.e., the front-to-back dimension of the tread including nosing):
Standard widths:
- 600 mm — the minimum width for single-person access staircases in industrial settings per EN ISO 14122-3. Suitable for maintenance access ladders and secondary escape routes with limited traffic.
- 800 mm — the standard width for general industrial access staircases. Provides comfortable single-person passage with clearance for hand-carried tools and equipment. This is the most commonly specified width for industrial platform access staircases.
- 1,000 mm — the wide-access width for staircases with higher traffic volumes, two-way pedestrian flow or accessibility requirements. Specified for primary access staircases, multi-storey platform installations and staircases serving as primary escape routes.
Standard depths:
- 240 mm — the compact depth for steep-angle staircases (inclination 38–45° per EN ISO 14122-3) and space-constrained installations. The going (Auftritt) provides adequate foot placement for industrial safety footwear.
- 270 mm — the standard depth providing comfortable foot placement for the majority of industrial staircase applications. Compatible with staircase inclinations of 30–38°, the most common range for permanent industrial access stairs.
- 300 mm — the generous depth for shallow-angle staircases (inclination 25–33°), multi-storey staircases with high traffic and applications where maximum comfort is required. This depth provides full-foot placement for all shoe sizes and is preferred for primary access staircases with frequent daily use.
The depth dimension includes the nosing overhang. Custom widths and depths outside the standard range are available on request for non-standard staircase configurations.
Bearing Bar Specification
Standard ULAMEX stair treads are manufactured with 30×3 mm bearing bars — the same specification used in the most widely specified industrial platform gratings. This commonality of bearing bar dimension ensures:
- Visual consistency between stair treads and landing/platform gratings within the same installation
- Equivalent load-bearing capacity, ensuring the stair tread can support the same loads as the platform it connects to
- Standardised connection details between treads and stringers
Bearing bar mesh opening is 30×30 mm standard. For applications requiring finer mesh (enhanced comfort, small-object-drop prevention), 30×10 mm mesh treads are available. For heavy-duty applications with concentrated loads or extreme traffic, 30×5 mm bearing bars can be specified for increased rigidity and load capacity.
Anti-Slip Performance — Serrated Stair Treads
Slip resistance on staircase treads is a critical safety requirement under workplace safety regulations and building codes. Stairs present a significantly higher slip and fall risk than level floors due to the inclined walking surface and the directional forces during ascent and, especially, descent.
ULAMEX supplies grating stair treads with serrated (toothed/knurled) bearing bars for applications demanding enhanced anti-slip performance. The serration pattern — a series of machined teeth on the upper edge of each bearing bar — creates a high-friction contact surface that maintains grip even in wet, oily or contaminated conditions.
Serrated stair treads achieve anti-slip classifications per DIN 51130:
- R11 — suitable for food preparation areas with moderate liquid contamination, washrooms, laundries and general wet areas
- R12 — suitable for kitchens, industrial areas with oil and grease, production floors with coolant spillage
- R13 — the highest classification (acceptance angle ≥35°), suitable for areas with heavy liquid contamination, outdoor industrial staircases exposed to rain and ice, food processing with fat and oil, and slaughterhouse environments
For exterior staircases, fire escapes and staircases exposed to rain, snow and ice, serrated treads with minimum R12 classification are strongly recommended. The combination of galvanized steel durability and serrated anti-slip performance makes these treads the preferred choice for demanding outdoor industrial environments.
Material and Corrosion Protection
All grating stair treads are manufactured from structural steel S235JR (1.0038) per EN 10025-2 and hot-dip galvanized after fabrication per DIN EN ISO 1461. The zinc coating thickness of 55–85 micrometres provides 30–50+ years of maintenance-free corrosion protection in typical industrial and outdoor atmospheres (corrosivity categories C2–C3 per EN ISO 9223). The galvanizing is applied after all fabrication operations (welding, bending, cutting) are complete, ensuring that the nosing bend, all cut edges and weld zones receive full zinc coverage.
Attachment Methods
Grating stair treads are attached to the staircase stringers (side beams) using one of two standard methods:
- Welded attachment — the tread is fillet-welded to the stringer angles or brackets. This provides a permanent, rigid connection and is the preferred method for heavy-duty industrial staircases where vibration resistance and long-term stability are primary requirements. After welding, the joint area should be touch-up galvanized (zinc-rich paint) to restore corrosion protection at the weld.
- Bolted attachment — the tread is bolted to stringer-mounted support angles or clips using galvanized bolts. This provides a removable connection that allows individual tread replacement without disturbing adjacent treads, and is preferred for maintenance-intensive environments where periodic tread replacement or access to services beneath the staircase is anticipated.
The choice between welded and bolted attachment depends on the specific installation requirements. ULAMEX can supply treads with pre-drilled bolt holes or plain (for welding) according to your staircase design.
Applications of Grating Stair Treads
Steel grating stair treads are specified for permanent access staircases in virtually every industrial and infrastructure sector:
- Industrial access staircases — multi-level access to production equipment, process platforms, control rooms and elevated machinery in manufacturing plants, chemical works, refineries and power stations
- External fire escape staircases — galvanized grating treads provide reliable grip in wet conditions, free drainage during rainfall and zero ice accumulation risk compared to solid treads
- Tank and silo access stairs — access to elevated storage vessels, mixing tanks, loading platforms and dosing systems in process industries
- Maintenance platform stairways — periodic access staircases to HVAC equipment, roof plant, lift motor rooms, antenna platforms and building services installations
- Wastewater treatment plant stairs — corrosion-resistant access between treatment levels, around settling tanks and across process areas with aggressive atmospheres
- Multi-storey warehouse and logistics mezzanine stairs — durable, low-maintenance staircase treads for daily traffic in high-use commercial environments
- Infrastructure and utility access — bridge inspection platforms, dam access ways, tunnel ventilation shaft stairs and railway infrastructure access points
Compliance with EN ISO 14122 and DIN 24531
All ULAMEX grating stair treads comply with EN ISO 14122-3 (Safety of machinery — Permanent means of access to machinery — Part 3: Stairways, stepladders and guard-rails), which specifies:
- Minimum tread width requirements (≥600 mm for single-person access, ≥800 mm for general access)
- Tread depth (going) requirements relative to staircase inclination angle
- Slip resistance requirements for tread surfaces
- Nosing visibility and contrast requirements
- Load-bearing requirements (minimum 1.5 kN point load at any position on the tread)
Manufacturing quality conforms to DIN 24531 (Steel gratings — technical delivery conditions) and dimensional tolerances conform to DIN 24537.
Ordering Grating Stair Treads
When ordering grating stair treads from ULAMEX, please specify:
- Tread width (600 / 800 / 1,000 mm or custom)
- Tread depth (240 / 270 / 300 mm or custom)
- Bearing bar specification (30×3 mm standard, 30×5 mm heavy-duty)
- Surface type (smooth bars or serrated bars for R11/R12/R13)
- Attachment method (for welding or pre-drilled for bolting)
- Quantity (number of treads per staircase × number of staircases)
Combine with platform gratings for landing platforms, and with structural steel stringers for complete staircase systems. ULAMEX delivers grating stair treads from stock in standard sizes, with custom dimensions available on short lead times.
Request a quote for galvanized grating stair treads — whether you need a single set of treads for a maintenance platform or hundreds of treads for a multi-level industrial installation, ULAMEX supplies across Europe with wholesale pricing and complete documentation.