A steel railing for stairs in a home is usually two things in one: a guard along the open side, at least 900 mm high inside a dwelling under the 2024 Ontario Building Code, and a handrail you can grip, mounted 865 mm to 1,070 mm above the tread nosings. Within those rules you choose the infill, the handrail profile, how it mounts to the stair, and the finish. Custom steel railings are fabricated to site measurements, so the order of decisions matters as much as the style.
This guide is for homeowners and contractors choosing a railing for an interior stair, basement stair or exterior steps. For the full code detail, see our guide to Ontario guard and handrail rules for steel railings.
Guard, handrail or both: what your stair needs
Start by working out which parts the stair actually needs:
- A handrail. Inside a dwelling unit, Table 9.8.7.1. requires a handrail on one side of a stair, straight or curved. Handrails aren't required on interior stairs with no more than 2 risers or exterior stairs with no more than 3 risers serving a single dwelling unit.
- A guard. Any open side where the drop is more than 600 mm needs a guard. An open basement stair, a stair beside a two-storey foyer and a landing that overlooks the floor below all need one.
- Both on the same side. On an open stair, the guard's top rail is often at guard height with a separate handrail fixed to the posts at handrail height. Where the heights line up, one rail can do both jobs, as long as it meets both sets of rules.
A stair between two walls typically needs only a wall-mounted handrail. A stair open on one side needs a guard there and a handrail on at least one side.
Picket, panel and glass infill styles
The infill is what most people mean by the style of a railing. Common options in steel:
- Vertical pickets. Round bar, square bar or flat bar pickets welded between a top and bottom rail. This is the simplest way to meet the opening and climbing rules, and it suits everything from traditional to modern interiors.
- Flat bar with a thin profile. Flat bar set edge-on gives a light, modern look. Spacing has to stay tight enough that a 100 mm sphere can't pass, even when neighbouring bars are pushed apart.
- Perforated or mesh panels. Steel sheet or welded mesh in a frame. They read as one plane and are easy to keep child safe.
- Glass with steel posts. Glass panels between steel posts and a steel handrail. Glass in a guard must be laminated or tempered safety glass to CAN/CGSB-12.1 or wired glass. See steel railings with glass for the details.
- Horizontal bars or cable. Popular online but a problem in Ontario homes. For required guards, Sentence 9.8.8.6.(1) says nothing between 140 mm and 900 mm above the walking surface may make the guard easier to climb. Horizontal infill in that zone generally doesn't comply.
On stairs there is one more opening to check: the triangle formed by the riser, the tread and the bottom rail must stop a 150 mm sphere. A bottom rail that follows the stair line close to the nosings takes care of it.
If you are still choosing materials, our comparison of steel vs aluminum vs glass railings covers the trade-offs.
Handrail profiles: what you actually hold
The handrail is the part people touch every day, so it deserves more thought than it usually gets. Sentence 9.8.7.5.(2) requires handrails to be continually graspable along their whole length, with nothing on or above them that breaks a handhold. The code's note explains that your fingers and thumb should be able to curl under part or all of the rail.
- Round tube or pipe. The easiest profile to grip and the standard choice for a steel handrail.
- Flat bar. Fine for posts, pickets and top rails, but a wide flat bar is hard to grip. If you like the flat look, add a separate round handrail where people hold.
- Wood on steel. A wood cap rail on a steel frame is warmer to the touch, which many homeowners prefer indoors.
- Wall-mounted rails. Steel handrails on brackets along a wall need at least 50 mm clear behind them, or 60 mm against a rough surface like stone or brick.
Within a dwelling unit, the handrail has to be continuously graspable from the bottom riser to the top riser, and it may start from a newel post or volute on the bottom tread. Handrail ends must not create a hazard. A return to the wall or into a post is the tidy steel detail.
How a steel railing mounts to the stair
How the railing attaches is the part that decides whether it feels solid. Handrails and their supports must resist a concentrated load of at least 0.9 kN at any point and in any direction (Article 9.8.7.7.), and guards have their own load requirements.
- Top-mounted posts sit on the treads or a curb with a base plate. Simple, but the plates are visible and the fasteners need solid material below.
- Side-mounted (fascia) posts fix to the face of the stringer. They keep the treads clear and suit steel and wood stairs with a solid stringer.
- Wall brackets carry wall-side handrails. For handrails serving a single dwelling unit that are fastened to wood studs or blocking, Sentence 9.8.7.7.(2) deems the attachment adequate where brackets are no more than 1.2 m apart, the end brackets are within 300 mm of the rail ends, and each point uses at least 2 No. 8 wood screws penetrating at least 32 mm into solid wood.
On concrete stairs the posts are anchored into the concrete, and edge distance matters because anchors close to a slab edge can break out. On steel stairs the railing is often welded or bolted to the stringers, which is the cleanest result. Our guide to Ontario Building Code rules for steel stairs covers the stair itself.
Interior railings vs exterior steps
Interior railings are usually painted or powder coated in black, bronze or white, and the main concerns are appearance and a smooth, consistent finish where hands touch.
Exterior steel railings for steps and porches have to handle water, salt and freeze-thaw. Look for:
- A coating system meant for exterior steel, such as galvanizing with paint over it
- Posts and tubes detailed so water drains out instead of collecting inside
- Bases that keep steel out of standing water on the concrete
- A handrail on exterior steps with more than 3 risers, where only one handrail is required for a single house
Most failures on exterior railings start at the base of a post, where rust attacks the welds and anchors that carry the load.
Measuring and ordering a custom steel railing
Steel railings are made to fit, and there is no trimming on site the way there is with wood. A typical sequence:
- Finish the stair first. Heights and gaps are checked from finished treads and floors, so flooring and tread caps should be installed or at least known before measuring.
- Site measure. Record the rise and run of each flight, the length of each run of railing, landing positions, wall locations and what the posts will fix into.
- Shop drawings. Heights, picket spacing, post positions and connections are drawn and checked against the code before cutting steel.
- Fabrication and finish. The railing is cut, fitted, welded and finished in the shop, often in sections sized to get through doors and up stairs.
- Installation. Sections are set, plumbed and fastened, and any field joints are finished.
For how these choices affect budget, see what drives steel railing cost per foot.
Getting a steel stair railing made
We fabricate custom steel stairs and railings in our shop in Erin, with CWB certified welding and shop drawings prepared in-house, and deliver across the GTA and Ontario. Send photos, a sketch with measurements, or drawings of your stair, and tell us the style you have in mind. We fabricate and deliver, and installation is by your installer or contractor.
Request a quote for your railing, or contact us with questions about your stair. You can also see our services for miscellaneous steel fabrication.
Frequently asked questions
How high should a steel stair railing be in a house?
Under the 2024 Ontario Building Code, a required handrail is 865 mm to 1,070 mm high, measured from a line through the tread nosings. A guard on the open side of a stair inside a dwelling unit must be at least 900 mm high, measured the same way.
Do house stairs need a handrail on both sides?
Inside a dwelling unit, stairs need a handrail on one side, whether straight or curved and regardless of width. Interior stairs with no more than 2 risers and exterior stairs with no more than 3 risers serving a single dwelling unit don't need one.
Can I use horizontal bars on a steel stair railing?
Not on a required guard in a house. The code requires that no member between 140 mm and 900 mm above the walking surface make the guard easier to climb, which rules out horizontal bars or cables a child could use as a ladder. Vertical pickets or solid panels are the usual choice.
Is a flat bar handrail allowed?
Handrails must be continually graspable, so your fingers and thumb can curl under part of the rail. A wide flat bar often fails that, so flat bar is normally used for posts, pickets and top rails, with a round or shaped handrail mounted where people hold it.
