Steel stairs and wood stairs follow the same Ontario Building Code rules for rise, run, width, headroom, handrails and guards, so the choice comes down to design, use and budget. Steel wins on open and floating designs, long spans, exterior stairs and heavy use, because it's strong with slim parts and holds its shape. Wood wins on warmth, quiet and ease of building a standard enclosed stair on site. Many of the best residential stairs use both: steel stringers with wood treads.
Here's how they compare, where each one makes sense, and what drives the cost of each.
Steel vs wood stairs at a glance
| Steel stairs | Wood stairs | |
|---|---|---|
| Look | Open, slim, modern or industrial | Traditional or warm; can be open or enclosed |
| Structure | Slim stringers or a single spine can carry long flights | Deeper stringers, often supported by walls |
| How it's built | Designed, then fabricated in a shop and installed | Usually cut and built on site by a carpenter |
| Noise | Can ring or drum without dampening or wood treads | Quieter, though older stairs creak |
| Feel underfoot | Cold and hard unless treads are wood, coated or covered | Warm and familiar |
| Exterior use | Good with a suitable protective finish | Needs treated or durable wood and maintenance |
| Changes on site | Hard after fabrication | Easy to trim and adjust |
| Moisture and pests | Not affected by rot or insects | Needs protection from moisture and ground contact |
Same code rules, different paths to compliance
The 2024 Ontario Building Code doesn't have separate dimensional rules for steel stairs. Rise, run, width, headroom, landings, handrails and guards are the same whichever material you choose; our guide to the Ontario Building Code for steel stairs covers those numbers.
Where the materials do differ is in how the stair is shown to be strong enough:
- Wood stairs have prescriptive rules. Article 9.8.9.4 sets minimums for wooden stair stringers: an effective depth of at least 90 mm and an overall depth of at least 235 mm, at least 25 mm thick if supported along their length or 38 mm if not, and spacing of no more than 900 mm in stairs serving a single dwelling unit. Article 9.8.9.5 sets wood tread thicknesses. A carpenter can build a compliant stair from those rules.
- Steel stairs are designed for the loads. There's no equivalent table for steel stringers. Article 9.8.9.1 requires stairs to be designed for strength and rigidity under specified loads of 1.9 kPa for stairs serving one dwelling unit (or a house with a secondary suite) and 4.8 kPa for other stairs. A steel stair is laid out and detailed on shop drawings, and stringer sizes and connections come from that design.
Two more code points come up with both materials:
- Open risers are allowed in stairs serving a single dwelling unit or a house with a secondary suite (Article 9.8.4.9), along with a few other cases such as service stairs. That's what makes open steel and floating stairs possible in houses. In most other buildings, stairs can't have open risers.
- Tread finish. Treads and landings must be wear-resistant and slip-resistant (Article 9.8.9.6). Inside dwelling units, other than stairs to unfinished basements, the finish must be hardwood, vertical grain softwood, resilient flooring or a material with equivalent performance. That's one more reason steel stairs in homes often get wood treads.
Guards and handrails apply either way. See OBC guard and handrail rules for steel railings.
Where steel stairs make sense
- Open and floating designs. A single steel spine or slim plate stringers can carry a flight with no wall support, which is hard to do in wood without deep members.
- Long flights and wide landings. Steel spans further with less depth, so landings and long runs can be supported with fewer posts.
- Exterior stairs. Steel isn't affected by rot or insects and, with a suitable finish, works well for decks, rear entrances and secondary-suite access. See exterior steel stairs.
- Basements with tight space. A steel stringer is much shallower than a wood one for the same span, which can help with headroom underneath.
- Heavy use and commercial spaces, where wear and long-term movement matter.
Where wood stairs make sense
- Standard enclosed stairs between walls, where a carpenter can cut stringers on site and match the rest of the house.
- Projects where things may change. Wood can be trimmed, shimmed and adjusted during construction. Steel has to be measured accurately before it's made.
- Quiet, warm interiors where the stair will be carpeted or finished to match hardwood floors.
- Renovations with tight access, where getting a welded steel stair into the house would be harder than building in place.
Steel and wood together
The search "staircase steel and wood" is common for a reason. The hybrid stair puts each material where it works best:
- Steel stringers or a central spine carry the load and give the open, slim look.
- Wood treads, often hardwood, sit on steel brackets or plates and give a warm, quiet walking surface that meets the tread finish rule for dwelling units.
- Steel guards and handrails, with or without glass infill, finish the look.
The steel side is fabricated with tread plates or angles drilled for fasteners, and the treads are installed after the frame is set. Good detailing of how the wood attaches, with allowance for wood movement, keeps the treads quiet over time.
What drives the cost of each
We don't publish prices because every stair is different, but the cost drivers are predictable.
Steel stair cost drivers:
- Layout: straight, L-shaped, U-shaped, switchback or spiral, and the number of landings
- Stringer type: a pair of plate or channel stringers is simpler than a mono-stringer or curved design
- Treads: steel checker plate, grating, pans for concrete or stone, or wood treads on steel
- Guards and handrails, which can be a large share of the total
- Finish: primer, paint, powder coating or galvanizing for exterior use
- Shop drawings, site measuring, delivery and installation
Wood stair cost drivers:
- Species and grade of treads, risers and stringers
- Open or closed stringers, and whether risers are open
- Custom curves, winders or landings
- Balusters, newels and handrails
- On-site labour and finishing (sanding, staining, painting)
A plain enclosed basement stair is usually simplest in wood. For a feature stair, a floating stair or an exterior stair, steel is often competitive with a custom wood stair of the same design. For a fuller breakdown, see how much steel stairs cost in Ontario and our comparison of steel stair kits vs custom.
Questions to settle before you choose
- Is the stair interior or exterior? Exterior strongly favours steel with a durable finish.
- Does the design need open risers or a floating look? Check it's permitted for your building type.
- How much noise is acceptable? If quiet matters, plan wood treads or dampening on a steel frame.
- Who builds it? A steel stair needs a fabricator, accurate site measurements and a plan for getting it into place.
- Is the stair part of a permit? New stairs and stair changes usually are. Have the design meet the OBC before fabrication.
Getting a steel or hybrid stair quoted
We fabricate custom steel stairs, including steel stringers made to take wood treads, along with railings. Send us your floor-to-floor height, opening size and any drawings or photos and we'll quote it. We fabricate and deliver, and installation is by your installer or contractor. See our steel products for the miscellaneous steel we make.
Frequently asked questions
Are steel stairs better than wood stairs?
Neither is better everywhere. Steel suits open, long or floating designs, exterior stairs and heavy use, because it spans further with slimmer parts. Wood is quieter and warmer underfoot, easier to modify on site and simple to build for a standard enclosed stair.
What are the disadvantages of a steel staircase?
Steel stairs can be louder underfoot, bare steel treads can feel cold or slippery without a suitable surface, exterior steel needs a protective finish, and the stair has to be designed and fabricated to exact site measurements, so changes after fabrication are harder.
Can you combine steel and wood in a staircase?
Yes, and it's one of the most popular residential options. Steel stringers or a central spine carry the load, and wood treads give a warmer, quieter surface. The steel is drilled or fitted with plates so the treads can be fastened.
Is a steel staircase more expensive than a wood staircase?
It depends on the design. A plain enclosed stair is usually simplest in wood. For open, long-span or exterior stairs, steel can be competitive, and a custom wood stair of the same design is not cheap either. Compare quotes for the same layout, treads, railings and finish.
