A steel railing with glass uses steel posts, rails or a stair stringer to carry the loads and safety glass panels as the infill. Under the 2024 Ontario Building Code, glass in a guard must be laminated or tempered safety glass (or wired safety glass), and in larger buildings Supplementary Standard SB-13 goes further, setting the type of glass by how close the panel sits to the edge of the floor. The steel side decides how stiff and durable the railing is; the glass side decides how safe it is when something breaks.
This guide covers how steel and glass railings are put together, the glass rules, glass on steel stairs, and what to settle before you order.
How steel and glass railings are built
There are four common ways to combine the two materials.
| System | How the glass is held | Look | What to know |
|---|---|---|---|
| Posts with clamps | Steel posts with glass clamps on each side of the panel | Posts visible, glass reads as panels | The most common and adjustable; posts carry the guard loads |
| Posts with channels | Glass sits in steel channels welded to the posts or a top and bottom rail | Framed panels | Glass is captured on more edges |
| Base shoe | Glass set into a continuous channel along the floor or slab edge | Almost frameless | The channel and its anchors carry everything, so they are heavily engineered |
| Standoffs (point-fixed) | Glass bolted to posts or stringers through drilled holes | Floating panels | Holes are drilled before tempering, so measurements must be exact |
Most custom steel and glass railings are the first two types: a welded steel frame, finished to suit the interior or exterior, with glass installed after the frame is set. A steel top rail or cap over the glass is common because it ties the panels together and gives you something to hold.
Ontario rules for glass in guards
Houses and small buildings (Part 9)
For buildings covered by Part 9 (houses, most townhouses and small buildings up to three storeys and 600 m²), Article 9.8.8.7. requires glass in guards to be:
- Safety glass of the laminated or tempered type conforming to CAN/CGSB-12.1, "Safety Glazing", or
- Wired glass conforming to CAN/CGSB-12.11-M, "Wired Safety Glass".
The rest of the guard rules still apply: height (generally 1,070 mm, or 900 mm inside a dwelling unit), openings that stop a 100 mm sphere, no climbable footholds between 140 mm and 900 mm, and the guard loads. A glass panel is not climbable in itself, which is one reason glass is popular where horizontal infill would be refused, but the gaps between panels and below the bottom edge still have to be under 100 mm. Our guide to OBC guard and handrail rules for steel railings covers each of these.
Larger buildings and condo balconies (SB-13)
In Part 3 buildings, glass in guards must conform to MMAH Supplementary Standard SB-13, "Glass in Guards". Exterior guards serving a single dwelling unit in those buildings, such as condo balcony guards, are included. SB-13:
- Allows only safety glass in a guard.
- Sets the glass type by location. Glass beyond the floor edge or within 50 mm of it must be heat strengthened laminated glass. Further than 50 mm in, heat soaked tempered glass is also allowed. Further than 150 mm in, plain tempered glass up to 6 mm thick is also allowed.
- Requires laminated glass to stay in its framing if it breaks.
- Requires the glass to be designed to Part 4 (structural design), with the guard load combined with wind on exterior balconies.
- Says glass must not be in direct contact with metal or similar hard elements of the guard, and the design must allow for deflection and thermal movement.
The point of those rules is that tempered glass can break without warning (heat soaking reduces that risk), and a broken panel on a high balcony can fall onto people below. Laminated glass stays in place.
Even on a house, where SB-13 doesn't apply, its detailing advice is good practice: gaskets or setting blocks between the glass and the steel, and room for the frame and the glass to move.
Tempered, laminated or heat soaked
| Glass type | When it breaks | Typical use in railings |
|---|---|---|
| Tempered (toughened) | Shatters into small pieces and leaves the frame | Interior guards and low exterior guards in houses |
| Heat soaked tempered | Same as tempered, but tested to reduce spontaneous breakage | Larger buildings where SB-13 allows it |
| Laminated (two or more layers bonded to an interlayer) | Cracks but stays held together on the interlayer | Balconies at height, base shoe systems, glass at the floor edge |
| Heat strengthened laminated | Plies are heat treated for strength but, unlike tempered glass, break into larger pieces that stay bonded to the interlayer | Required by SB-13 at and beyond the floor edge |
Thickness and type are set by the glazier or the railing designer for the span, height and loads. Glass is cut, drilled and tempered before delivery and can't be trimmed on site, which is why the steel frame has to be built and measured accurately first.
Glass on steel stairs
A steel staircase with a glass balustrade is one of the most requested combinations in modern homes. A few details make the difference:
- Raked panels. Glass along a stair is cut to the stair angle, usually as parallelograms. Each panel is measured from the installed stair, not the drawing.
- The triangle at the treads. On stairs, the triangular opening between the riser, the tread and the bottom of the guard must stop a 150 mm sphere. Glass that follows the stair line close to the nosings takes care of it.
- A real handrail. Required stair handrails must be 865 mm to 1,070 mm above the nosings and continually graspable. A glass edge or a flat cap isn't a handrail, so a round or shaped rail is mounted on the posts, clamped to the glass, or fixed to the wall side.
- Fixing to the stringer. Side-mounted clamps or a channel welded to a steel stringer keep the treads clear and give a clean line. The stringer has to be stiff enough that the glass isn't flexed as people use the stair.
For stair railing styles beyond glass, see steel stair railings and handrails, and for the stair itself, Ontario Building Code rules for steel stairs.
Planning a steel and glass railing
- Decide the system (clamped, channel, base shoe or standoff) with the look and the floor edge in mind.
- Confirm which rules apply. Part 9 safety glass rules for a house, SB-13 for larger buildings and condo balconies.
- Lay out posts and panel widths so the glass panels are a sensible size to handle and replace.
- Build and install the steel first, then template the glass from the as-built frame.
- Coordinate the trades. The steel fabricator and the glazier need to agree on clamp positions, gaskets, tolerances and who supplies what.
- Choose the steel finish for the location. Outdoor steel frames are normally galvanized, often with a colour coat over it.
On cost, glass railings involve two supplies and more coordination than a picket railing. The number of panels, raked stair panels, the glass type and the fixing system all move the price. Our guide to what drives steel railing cost per foot covers the steel side.
Steel railings with glass from Procut
We fabricate custom steel railings and stairs, including steel posts, frames and stringers detailed to take glass panels, with CWB certified welding and shop drawings prepared in-house. We deliver across the GTA and Ontario, and engineering services are available for projects that need them. We fabricate and deliver the steel; glass supply and installation are by your glazier, installer or contractor.
Send your drawings, measurements or photos for a free quote, or see our services for the miscellaneous steel work we do.
Frequently asked questions
What glass is used in a steel railing?
Glass in a guard must be safety glass. For houses and small buildings under Part 9 of the Ontario Building Code, that means laminated or tempered glass to CAN/CGSB-12.1, or wired glass to CAN/CGSB-12.11-M. Larger buildings follow Supplementary Standard SB-13, which sets the glass type by how close the panel is to the floor edge.
Is toughened glass safe for a railing?
Toughened (tempered) glass is a safety glass, but when it breaks the whole panel falls out as small pieces. Laminated glass holds together on its interlayer. That's why SB-13 calls for laminated or heat soaked glass near the edge of a floor in larger buildings.
Can a glass railing be used on a steel staircase?
Yes. The glass is usually cut to the stair angle and held by steel posts, clamps or a channel along the stringer. The stair still needs a graspable handrail at 865 mm to 1,070 mm above the nosings, and the openings at the bottom must meet the code.
Does a glass railing still need a handrail?
On stairs, yes. A glass panel is a guard, not a handrail. Required stair handrails must be continually graspable, so a round or shaped handrail is mounted on the posts or glass, or on the wall side.
