Choose a thin anti-slip cover for a sound existing stair, a molded grating tread for drainage and bidirectional layouts, or a pultruded T-bar tread for longer one-way spans. Reference sizes, decision gates and RFQ inputs are organized below.
Send quantity × width × depth, substrate photos, environment and destination.
Start with the existing stair and required load path. Product depth comes after that decision—not before it.
Keep the existing stair
Best for: Structurally sound steps that are slippery, worn or visually poor.
Shortlist: 305 or 343 mm nominal depth × 3.2 mm; cut from a 3,658 mm supplier-reference length.
Do not cover through-corroded steel, loose masonry, spalled concrete or a failed stringer.
Review this option
Replace the whole tread
Best for: New or replacement stairs where water, ice, dirt or washdown must drain through.
Shortlist: 25 or 38 mm molded panel depth with square or mini mesh and an integral grit nosing.
Do not release from depth alone; mesh opening, support width and load table still govern.
Review this option
Carry a longer clear width
Best for: New stair flights governed by one-way span, directional stiffness or project-specific deflection.
Shortlist: 25 or 38 mm pedestrian T-bar series with fine or coarse grit and optional contrasting nosing.
Bearing-bar direction cannot be rotated casually; end plates and stringer connections must match the drawing.
Review this option1 · Existing structure
Yes: shortlist a cover. No or uncertain: repair the substrate or replace the complete tread. A cover is not structural rehabilitation.
2 · Drainage
Choose molded or pultruded open grating. Use a solid cover only where it will not create a drainage or cleaning problem.
3 · Span and load
A cover relies on the old step. A new tread needs support spacing, uniform and point loads, deflection limit and bearing detail.
4 · Access rules
State accessibility, heel-opening, slip, fire and color-contrast requirements. A grit label alone is not a compliance certificate.
The two cover rows are metric conversions of the supplied manufacturer reference. Molded and pultruded rows are selection families tied to F1's dedicated grating data. None is an order code, guaranteed stock position or certified load value.
Release boundary: covers rely on the existing step. Complete grating treads require an approved load/span check, support detail and fabrication drawing.
| Family | Best for | Tread depth | Length / width | Structural depth | Surface & nosing | Release basis |
|---|---|---|---|---|---|---|
| Retrofit cover · 12 in reference | Sound steel, concrete, timber or brick steps | 305 mm (12 in) | 3,658 mm (144 in) stock reference; cut to schedule | 3.2 mm (1/8 in) | Solid coarse-grit top; black with yellow leading edge | Confirm substrate, cut length, nose return, resin and fixing schedule |
| Retrofit cover · 13.5 in reference | Deeper sound existing steps and landings | 343 mm (13.5 in) | 3,658 mm (144 in) stock reference; cut to schedule | 3.2 mm (1/8 in) | Solid coarse-grit top; black with yellow leading edge | Confirm substrate, cut length, nose return, resin and fixing schedule |
| Molded grating tread | New stairs, drainage, frequent wet or corrosive exposure | Project tread depth; cut from approved panel layout | Project clear width and end-bearing detail | 25 or 38 mm shortlist; other catalog depths available | Open square or mini mesh; grit top; contrasting integral nosing | Load table, support spacing, mesh opening and approved tread drawing |
| Pultruded T-bar tread | Longer one-way spans and higher directional stiffness | Project tread depth; fabricated from T-bar grating | Project clear width and bearing direction | 25 or 38 mm pedestrian T-bar shortlist | Open T-bar surface; fine/coarse grit; contrasting nosing option | Series load table, span/deflection check and approved end-plate detail |
Record every flight as quantity × width L × tread depth D × nose return H. Note rear obstructions, side clearances and whether the existing nosing projects beyond the riser.
Supplier-reference application photography; shown for selection context, not as an F1 project case study.
If the tread has lost section, the connection is unreliable, drainage is essential or the stair is new, move to a complete grating tread.
Mesh, depth, cut, nosing, bearing and clip/end-plate detail.
Bearing direction, series, span, loads, deflection and end plates.
Stair slope, rail height, returns, posts and load basis.
Schedule, drawing, load table, resin/surface spec and hardware BOM.
This is a selection-stage overview. The order drawing controls fastener material, holes, spacing, adhesive if used and cut-edge sealing.
Remove loose coatings and verify that every existing tread, connection and stringer remains structurally adequate. Repair corrosion, spalling or movement before covering.
Set each cut cover in place, confirm nosing alignment and clearances, then mark the approved fixing pattern. Do not force a cover over protrusions.
Use the approved hole clearance, washer and corrosion-compatible hardware. The supplier reference starts about 152 mm from each end and adds fixings at roughly 610 mm intervals where required; the F1 drawing controls.
Check seating, fastener heads, nosing alignment, sealed cut edges where required, surface cleanliness and final security before returning the stair to service.
Use a cover when the existing steel, concrete, timber or masonry step is structurally sound and only needs a durable anti-slip surface and visible nosing. Use a complete molded or pultruded tread for new construction, drainage, or when the old tread cannot be relied on structurally.
The supplied manufacturer reference lists 305 mm or 343 mm tread depth, both 3,658 mm long and 3.2 mm thick (12 or 13.5 in × 144 in × 1/8 in). These are selection references, not F1 inventory promises. The quotation confirms cut length, nose return, resin, color, tolerances and availability.
No. A cover improves the walking surface but does not replace the capacity of a corroded steel tread, spalled concrete step, loose timber board or failed stringer. Assess and repair the substrate, or replace the complete tread, before installation.
Molded grating is bidirectional and suits wet corrosive duty, irregular cutouts and square- or mini-mesh layouts. Pultruded T-bar carries primarily in the bearing-bar direction and is the usual shortlist when longer one-way spans or directional stiffness govern. The load table and approved drawing decide the final series.
Clean and dry the surface, dry-fit and predrill the cover, then use the approved mechanical fixing and washer arrangement. The supplier reference places end fixings about 152 mm from each end and adds fixings at about 610 mm intervals as required. Substrate and exposure can change that layout, so the F1 detail controls.
No. Coarse or fine grit describes construction, not a universal compliance result. State the required test method and acceptance value in the RFQ so the available surface and order-specific evidence can be confirmed before release.
Isophthalic polyester is a common baseline, with vinyl ester for more demanding chemical exposure and fire-retardant formulations where specified. Resin name alone does not establish compatibility or a fire class; provide the chemical, concentration, temperature and required report standard.
Send quantity, width, depth and nose return; substrate and stringer photos; load and clear support spacing for complete treads; exposure, surface, color, resin/fire documentation, hardware preference and destination. A marked photo or drawing prevents the most common sizing mistakes.
Our FRP Engineering Advisor answers spec, sizing, and chemical-compatibility questions instantly — and routes complex ones to the right human.
Pre-filled question: “I need FRP stair treads. Existing stair and substrate [details], option [cover / molded / pultruded / unsure], quantity and dimensions [width × depth × nose], span and loads for full treads [details], environment and surface/fire/accessibility requirements [details], destination [city/country]. Please recommend the family and list missing RFQ inputs.”
Catalog dimensions identify standard section options, not live inventory. Confirm tooling, material, quantity and production timing in the quotation.
Confirm that the document and project match your proposed product.
Include the drawing, resin or environment, loads, quantity and destination.
Request a specification reviewSend the dimensions, quantity, service environment, and destination. We acknowledge requirements within one business day.