Metal Stairs and Railings: Ontario Building Code

Few elements in a commercial or industrial building get scrutinized as hard as the egress stair. It carries people on their worst day, it gets inspected closely, and it has to satisfy a long list of dimensional and structural rules.

If you are specifying or building metal stairs and railings to the Ontario Building Code, the difference between a clean sign-off and an expensive rework usually comes down to details that were decided in fabrication: guard height, handrail profile, infill spacing, tread type, and how the stair ties into the surrounding structure. This guide walks through what actually matters when you order metal stairs and railings and handrails for a code-governed project in Ontario.

Guard height and infill: the rule everyone checks first

Guards exist to stop people from falling off the open side of a stair, landing, ramp or platform. Under the Ontario Building Code, the required guard height depends on the application and the height of the drop, with interior and exterior guards on stairs and landings generally falling into well-known ranges, and higher guards required where the walking surface sits well above the adjacent grade or floor.

The practical takeaway for fabrication is that the guard has to be the right height measured from the leading edge of the tread or the finished landing surface, not from some arbitrary point on the stringer.

Infill is the second half of the equation. Where a guard could be climbed by small children or where openings would let a small body pass through, the spacing between vertical members is limited so that a small sphere cannot pass through the gap. For industrial settings this often means vertical picket guards rather than horizontal rails, since horizontal members can read as a ladder.

We fabricate guards with picket spacing, mid-rails and toe protection to suit the occupancy, and we will flag early if a horizontal-rail look you have in mind conflicts with the climbability and opening-size limits.

Graspable handrails: profile, projection and continuity

A guard keeps you from falling off; a handrail gives you something to hold while you climb. The Code is specific about handrails being graspable, the cross-section has to be a size and shape a hand can actually close around, which is why a wide flat bar on edge does not qualify on its own and why round or oval profiles in the right diameter range are the safe default.

Handrails also need to be mounted at the correct height above the tread nosings, continuous along the flight, and set off the wall far enough to leave clearance for knuckles.

On longer or wider stairs you may need handrails on both sides, and on very wide egress stairs an intermediate handrail down the middle. These are the kinds of requirements that are cheap to build in and painful to retrofit. When we quote railings, we confirm the graspable profile, mounting height, return-to-wall details and bracket spacing so the installed handrail is something an inspector signs off without a conversation.

Loads: stairs, guards and handrails all carry them

Code-compliant does not stop at dimensions. Stair stringers, treads, landings, guards and handrails all have to resist specified loads, uniform and concentrated live loads on the walking surface, plus point and linear loads applied to the top of guards and along handrails to simulate a crowd pushing or a person catching a fall.

Industrial access stairs and platforms can attract higher loading than a typical building stair, and the right answer is driven by how the structure will actually be used.

This is where fabrication and engineering meet. We size stringers, tread connections, guard posts and base plates so the assembly carries its design loads with proper connections back to the supporting steel. If your project has unusual loading, heavy equipment carts, maintenance access, or public assembly, tell us up front so the members and welds are sized for it rather than for a generic minimum. Our engineering audience page covers how we work load cases into a fabrication.

Treads: grating versus checker plate

The tread is where slip resistance, drainage, debris and weight all compete. For interior stairs and clean dry environments, checker plate (diamond-tread) treads give a solid, easy-to-clean surface with a raised pattern for grip. For exterior egress stairs, wash-down areas, and anywhere water, snow, ice or grit collects, bar grating treads are usually the better call, the open surface drains and sheds debris instead of holding a slick film on top.

• Bar grating treads, open, self-draining, excellent for exterior and wet or dusty environments; nosings can be serrated or fitted with an abrasive strip for added grip.
• Checker plate treads, closed surface, easy to sweep and wash, good for interior stairs and where you do not want anything dropping through.
• Anti-slip surfaces, for high-traffic or safety-critical stairs we can specify anti-slip grating and serrated nosings to push slip resistance higher.

Whatever the tread, the nosing geometry, tread depth and riser height all fall under the Code's stair-dimension rules, so we build to those dimensions rather than to whatever happens to be convenient on the bench.

Galvanizing for exterior egress stairs

Any stair that lives outdoors in an Ontario winter is fighting salt, freeze-thaw and standing water. Hot-dip galvanizing is the workhorse finish here: it coats every surface, including the inside of hollow sections and the threads of connections, and it holds up for decades in exposed service. For stairs, landings and guards on the building exterior, galvanized components are usually the most cost-effective way to get a long maintenance-free life.

Where appearance matters, architectural entry stairs, public-facing guards, galvanizing can be paired with a duplex powder-coat system, and for corrosive or hygienic environments stainless steel is an option. Our metal and finish guide lays out the trade-offs, and the post on galvanized vs stainless vs powder-coated goes deeper on durability per dollar.

Coordinating with the structural steel

A stair is only as good as what it lands on. The stringer-to-floor connections, landing supports, guard-post anchorage and any wall-mounted handrail brackets all have to bear on real structure, not on a finish or an afterthought. The cleanest projects are the ones where stair and guard connections are coordinated with the building frame from the start.

Because we also handle structural steel fabrication, we can detail the stair, its landings and the supporting framing together, and supply matching access platforms and mezzanines so guards, toe plates and handrails run continuously across the whole assembly. See the structural steel hub and platforms and access hub for the full range.

Drawings and engineering coordination on every fabrication

None of the above works if it lives only in someone's head. We treat documentation as part of the deliverable: before any steel is cut, we produce full structural and shop drawings for the stair, guards and handrails, and we work directly alongside your project's engineer of record and design team so the fabricated assembly matches the stamped intent.

That means connection details, member sizes, finishes, tread types and guard geometry are all on paper, reviewed and signed off before fabrication starts, so what arrives on site is what was approved, and the inspector has a clear record to check against. Architects and engineers can see how this collaboration runs on our page for architects and page for engineers.

A note on what "code-compliant" means here

We build to the dimensional and structural requirements of the Ontario Building Code, guard heights, graspable handrail profiles, opening limits, tread and riser dimensions, and design loads, and we coordinate with your design team so the final assembly satisfies the version of the Code that applies to your project and occupancy.

The authority on any specific clause is your engineer of record and the local building official; our job is to fabricate accurately to the drawings and to flag conflicts early. If you are a builder coordinating trades, our general contractors page explains how we slot into a construction schedule, and facility teams can start with the property managers page.

Getting it specified right

If you are at the drawing stage, the best time to lock down guard height, handrail profile, tread type and finish is now, before fabrication and before inspection. Send us your stair and railing drawings, or just the loads, dimensions and environment, and we will come back with a buildable detail and a quote. Whether you need supply-only for your own installers or supply-and-install, we fabricate in-shop in Ontario and ship across Canada.

For more on the engineering side, the grate load class guide and the post on grate load classes explained are useful background for any tread or platform decision.