The main types of steel stair treads are checker (diamond) plate, steel bar grating, steel pans filled with concrete, perforated or expanded metal plank, and steel frames carrying wood, stone or precast treads. Grating is the usual choice outdoors and in plants, pans filled with concrete are standard in commercial stairwells, and checker plate suits covered utility stairs. The right tread depends on where the stair is, who uses it, whether the risers must be closed, and how the tread attaches to the stringers.
Steel stair treads compared
| Tread type | What it is | Best for | Watch for |
|---|---|---|---|
| Checker plate | Steel plate with a raised pattern, often with bent nosing and end tabs | Interior utility stairs, covered service stairs, mezzanine access | Holds water and ice outdoors; can be noisy; may need stiffening on wide stairs |
| Bar grating | Load-bearing bars with cross bars, with end plates and a nosing | Exterior stairs, industrial and roof access stairs, platforms | Open, so not suitable where closed risers are required; heel-catching in some spaces |
| Concrete-filled pan | Bent steel tray filled with concrete on site | Commercial and multi-unit stairwells, exit stairs | Needs a concrete trade; heavier; temporary fill or protection before concrete |
| Perforated or expanded metal plank | Formed plank with raised, punched openings | Exterior and industrial stairs needing grip and drainage | Check opening size suits the users; lighter feel |
| Plate tread with finish | Smooth plate or folded plate topped with wood, tile, stone or a resilient finish | Feature stairs in homes and offices | Finish thickness changes the rise at top and bottom |
| Steel frame for other treads | Brackets, angles or folded plate carrying wood, stone or precast treads | Residential and feature stairs | Tread material and fixings designed with the frame |
Checker plate treads
Checker plate, also called diamond plate or floor plate, is plate rolled with a raised pattern for grip. A tread is usually cut from plate, with the front edge bent down to form the nosing and tabs or angles at each end for bolting or welding to the stringers. A back edge can also be bent up to act as a short riser.
Thickness and stiffening come from the span between stringers and the load. Plate treads are often in the 6 mm to 10 mm (1/4 in to 3/8 in) range, and wide treads may need an angle or bent stiffener underneath to stop them flexing. Plate is widely stocked in imperial thicknesses, so a metric thickness on the drawing may be supplied as the nearest imperial plate. More detail on sizes and uses is in our guide to steel checker plate.
Indoors, checker plate is durable and easy to clean. Outdoors it holds water, slush and ice on the flat surface, so it is better under a roof.
Steel bar grating treads
Grating treads are made from bearing bars (the flat bars on edge that carry the load) joined by cross bars, usually welded. Each tread has end plates welded on for bolting to the stringers, and a nosing along the front edge. Common nosing types:
- Checker plate nosing: a bent strip of checker plate welded along the front
- Abrasive nosing: a cast or bonded abrasive strip for extra grip and visibility
- Plain bar nosing: the front bearing bar alone, which is the least visible edge
Grating depth and bar spacing are chosen from the grating manufacturer's load and span tables for the stair width and loading. Serrated bars add grip on exterior and oily surfaces.
Grating lets snow, water and debris fall through, which is why it dominates exterior and industrial stairs. Because it is open, it also creates an open riser stair unless separate riser plates are added. See exterior steel stairs for outdoor tread choices.
Concrete-filled pan treads
A pan tread is a shallow steel tray, usually formed from bent plate with an integral riser and a nosing at the front, welded or clipped between channel stringers. After the stair is installed, the pans are filled with concrete, giving a solid, quiet walking surface. Landings are formed the same way with steel deck or plate pans.
Pan stairs are the common stair in commercial and multi-unit stairwells because the steel goes in early, the risers are closed, and the concrete finish behaves like a concrete stair. They do need a concrete trade to fill them, and until they are filled, the empty pans are a trip and fall hazard, so sites usually fill them temporarily or restrict use. We cover these in detail in what are steel pan stairs.
Steel frames for wood, stone and precast treads
Many residential and office stairs use steel for the structure and another material for the tread. The steel provides stringers and tread supports (angles, brackets, folded plate or a mono stringer with cantilevered arms), and the treads are fastened from below.
The 2024 OBC sets finish rules for interior stairs in dwelling units: treads and landings, other than stairs to unfinished basements, must be hardwood, vertical grain softwood, resilient flooring or another material providing equivalent performance. That is one reason home stairs often combine a steel frame with wood treads. Our steel stairs with wood treads guide covers the attachment details.
Risers, nosings and code points for steel treads
The 2024 Ontario Building Code applies to the tread whatever it is made of. Points that affect steel treads in particular:
- Nosings. The top of each tread nosing needs a rounded or bevelled edge extending 6 mm to 14 mm horizontally from the front of the nosing (as little as 3 mm where a resilient nosing cover is used). A square-cut plate or grating edge needs to be broken or covered.
- Tread depth. For rectangular treads, the depth must be at least the run and no more than the run plus 25 mm, which limits how far the nosing can overhang the tread below.
- Open risers. Stairs must have closed risers, except stairs serving a single dwelling unit or a house with a secondary suite, fire escape stairs, stairs principally used for maintenance, stairs serving service rooms, and stairs serving most industrial occupancies.
- Slip resistance. Treads and landings must be wear-resistant, slip-resistant, smooth, even and free from open defects. Outside dwelling units, they need a slip-resistant finish or slip-resistant strips that stand no more than 1 mm proud.
- Leading edge marking. Outside dwelling units, service rooms and service spaces, the leading edges of treads and landings need a colour contrast or distinctive visual pattern, and most of these stairs need a tactile attention indicator at the top.
Rise and run limits for each stair type are covered in Ontario Building Code rules for steel stairs.
Choosing the tread
A quick way to narrow it down:
- Exterior and uncovered: grating, or perforated plank where a finer surface is wanted
- Commercial exit stair with closed risers: concrete-filled pans
- Covered utility or service stair: checker plate or grating
- House or office feature stair: steel frame with wood, stone or a finished plate tread
- Industrial platform access: grating with serrated bars and abrasive nosings
The tread and the stringer are designed together, since the tread span sets the stringer spacing and the connection details.
Steel stair treads and stairs from Procut
We fabricate custom steel stairs, treads, landings and railings, with shop drawings prepared in house and CWB certified welding, and deliver across the GTA and Ontario. Send drawings or site measurements with the tread type you have in mind, and we'll quote the stair or the treads alone.
Request a quote, or see our steel products for plates, channels and miscellaneous steel.
Frequently asked questions
What are the types of steel stair treads?
The main types are checker (diamond) plate treads, steel bar grating treads, steel pans filled with concrete, perforated or expanded metal plank, and steel frames or brackets carrying wood, stone or precast treads. Each suits different locations and loads.
How thick should a steel stair tread be?
It depends on the tread type, the stair width and the load. Plate treads are often in the 6 mm to 10 mm (1/4 in to 3/8 in) range with stiffening where needed, and grating depth is chosen from the manufacturer's span tables. The tread is sized by design with the stringer spacing.
What is a steel stair nosing?
The nosing is the front edge of the tread. On steel stairs it may be a bent edge on a plate tread, a checker plate or abrasive nosing welded to grating, or a steel angle at the front of a concrete-filled pan. The 2024 Ontario Building Code requires a rounded or bevelled edge of 6 mm to 14 mm on the top of tread nosings.
Are open grating treads allowed on stairs in Ontario?
Open risers are only allowed in certain places under the 2024 OBC, such as stairs serving a single dwelling unit, fire escapes, maintenance stairs, stairs serving service rooms and most industrial stairs. Elsewhere, stairs need closed risers, which affects the choice of tread.
Which steel stair tread is best for outdoors?
Steel bar grating is the most common exterior choice because water, snow and debris pass through it. Checker plate holds water and can ice over, so it is better under cover.
