Mono-Stringer vs Double-Stringer Floating Staircase: Ontario Comparison
Choosing between a mono-stringer and double-stringer floating staircase is the most important structural and aesthetic decision for your Ontario staircase project. Both create a floating effect. Both require P.Eng engineering. Both use the same tread species and railing options. But they look different, cost different amounts, and make different structural demands on your home’s floor framing. This page gives you the clear comparison you need to make the right choice.
Mono-Stringer: Maximum Floating Effect
A mono-stringer uses a single central steel beam. Treads cantilever out on both sides — no visible support beneath them from any direction. The underside of the staircase is completely open. The sightline passes through and under the staircase without interruption. This is the maximum floating effect — the staircase appears to defy gravity.
The structural requirement: the single stringer must carry all live load through the cantilever bracket connection. This requires a heavier steel section, higher-capacity anchor plates, and P.Eng engineering for every installation — the specific geometry of your staircase determines the required section size. C.O.R.S includes P.Eng engineering in every mono-stringer quote.
Double-Stringer: Linear Design Feature
A double-stringer uses two steel stringers — one on each side of the staircase. Treads are supported at both ends. The stringers are visible as parallel lines framing the staircase. The visual result is contemporary and graphic — the linear stringer profile becomes a deliberate design element rather than a hidden structural component. The load per stringer is lower than a mono-stringer, typically allowing smaller section sizes.
Structural Comparison
| Factor | Mono-Stringer | Double-Stringer |
|---|---|---|
| Anchor points | 2 (top and bottom) | 4 (2 top, 2 bottom) |
| Load per anchor | Higher (full load) | Lower (shared) |
| Floor framing requirement | Solid header at centreline | Solid at two outside edges |
| P.Eng required | Always | Always |
| Steel section size | Larger | Smaller |
Visual Comparison: Which to Choose?
Choose mono-stringer when: Your interior is pure open-concept with long sightlines. The staircase is the visual centrepiece of the main floor. You want maximum transparency — the completely floating effect. The railing is frameless glass. Budget allows the premium.
Choose double-stringer when: Your interior has an industrial, loft, or contemporary-craft aesthetic. The visible stringer profile is a design feature. You are using cable railing or vertical rod infill — materials that complement the linear stringer. The budget is a meaningful consideration — the double-stringer saves $4,000–$7,000 over an equivalent mono-stringer.
2026 Ontario Pricing Comparison
| Configuration | Railing | All-In Price |
|---|---|---|
| Double stringer, cable railing | 316 stainless cable | $13,000–$19,000 |
| Double stringer, frameless glass | Frameless glass | $18,000–$27,000 |
| Mono-stringer, semi-frameless glass | Semi-frameless glass | $20,000–$28,000 |
| Mono-stringer, frameless glass | Frameless glass | $22,000–$32,000 |
| Mono-stringer, walnut + frameless | Frameless glass | $28,000–$40,000 |
Frequently Asked Questions
Can a mono-stringer be converted to a double-stringer later?
No — the two systems have fundamentally different anchor designs. Conversion would require full staircase replacement.
Is a mono-stringer structurally safer?
Both configurations, when P.Eng engineered to OBC live load requirements, are equally safe. Safety is a function of engineering quality, not stringer count.
Which is more popular in Barrie and Simcoe County?
Mono-stringer represents approximately 65% of C.O.R.S floating staircase installations. Double-stringer represents 35%.
Does a permit cover both configurations?
Yes — OBC Part 9 and municipal building permit requirements apply equally to both configurations. The permit process is identical.
Book Your Free Floating Staircase Consultation
C.O.R.S designs both configurations across Ontario. Call (705) 623-0371 or read our complete Ontario floating staircase guide.