The staircase is no longer just a simple transition between two floors. In modern staircase design, it has become a statement piece, a functional sculpture that defines the character of a space. At the heart of its design lies a fundamental structural decision that influences its overall look, lightness, and integration: the choice of stringer.
The stringer is the backbone of the staircase, the beam that supports the treads. In this role, two approaches stand out: the central stringer staircase, which offers a clean and singular line, and the double stringer staircase (or side stringers), which frame the steps in a more traditional or industrial way.
For architects, engineers, contractors, and discerning homeowners, understanding the implications of this choice is essential. It impacts not only the appearance but also space usage, structural complexity, and overall cost. As a custom metal structure expert, Métanox offers a complete guide to help you make the right choice.
Central Stringer Staircase: The Essence of Minimalism
The central stringer staircase is without a doubt the icon of the contemporary open staircase. It consists of a single structural beam, usually steel, positioned directly under the centre of the steps.
Aesthetics and Style:
Its main advantage is its visual lightness. By concealing the main structure, it gives the impression that the steps are floating in the air. This is the top choice for architectural minimalism, creating clean lines and a sense of openness. It maximizes light penetration and minimizes its visual footprint, making it an ideal self-supporting structure for open spaces.
Structure and Installation:
The apparent simplicity of the central stringer hides greater technical complexity. All the staircase’s load rests on this single beam, which must be designed and manufactured with absolute precision to ensure perfect rigidity and avoid any flex or vibration. Installing this type of staircase is more technical and requires specialized know-how, especially for anchoring at the base and upper floor.
Double Stringer Staircase: The Strength of Versatility
The double stringer staircase, or side stringers, is the most classic configuration. It consists of two beams that frame the steps on each side.
Aesthetics and Style:
Far from being plain, this configuration offers great versatility. Depending on design and materials, it can evoke a raw industrial style (with bare steel stringers and visible bolts), a more classic and refined style, or even a modern design with laser-cut stringers. It conveys a stronger sense of solidity and presence in a room.
Structure and Installation:
Load distribution over two supports often makes structural design simpler. The stringers can be less massive individually, and installation is generally more straightforward for contractors, especially for straight configurations.
Comparison: Central vs. Double Stringers
| Criterion | Central Stringer | Double Stringers |
| Aesthetics and Style | Modern, minimalist, airy, “floating.” Ideal for clean design. | Versatile: traditional, industrial, classic, or modern. More massive look. |
| Space Usage | Frees visual space on the sides. Maximizes light and openness. | Frames the staircase, which can make it appear more imposing. |
| Structure and Stability | Requires precision engineering. The central beam must be very robust. | Load is shared, simplifying design and providing high rigidity. |
| Railing Compatibility | Perfect for glass railings fixed to treads for an “all-glass” effect. Elegant offset options. | Highly flexible. Railings can be fixed directly to stringers (glass, metal, cables, etc.). |
| Tread Compatibility | Ideal for thick solid wood treads or folded metal steps for a floating effect. | Maximum compatibility: wood, metal, glass, lightweight concrete. |
| Installation Complexity | More technical and time-consuming. Often requires 100% custom fabrication. | Simpler and faster, especially with standard stringers. Fewer adjustment constraints. |
| Overall Cost | Generally higher due to engineering, heavier main beam, and installation. | More affordable, especially with standard configurations. Custom work can increase cost. |
In-Depth Analysis: Beyond the Table
Railing Impact
The choice of stringer directly influences railing design.
With a central stringer, glass railings are the top choice. Fixed directly to the treads or with discreet clamps, they preserve transparency and lightness.
With double stringers, possibilities multiply. The railing can become a design feature in itself, with steel posts, cable infills for a nautical or industrial look, or large glass panels for a contemporary style.
Feel Underfoot
Although both types, if well-designed, are perfectly safe and up to code, perception may vary. A very high-quality central stringer staircase will be perfectly rigid. However, a lower-quality design may introduce slight flex or vibration underfoot, which you will never feel with a double stringer. This is where the expertise of a manufacturer like Métanox becomes essential.
Material Combinations
The current trend is to combine materials for rich contrasts.
- Modern favourite: A central stringer staircase in matte black powder-coated steel, solid wood treads (oak or walnut), and extra-clear glass railing. The hallmark of a successful contemporary interior.
- Industrial chic: A double stringer staircase in varnished raw steel, aged wood treads, and a railing with metal mesh or steel cables.
Conclusion: Which Is Right for Your Project?
The choice is not simply “central vs. lateral,” but “what story do you want your staircase to tell?”
- Choose the central stringer if your top priority is architectural minimalism, light, and creating a sculptural, airy centrepiece. You are ready to invest more in a design that stands out.
- Choose double stringers if you want stylistic versatility, a stronger aesthetic presence (whether industrial or classic), or if your budget and installation constraints favour a more straightforward, proven solution.
Whatever your vision, the success of your project depends on fabrication quality. A custom metal structure, precisely designed and expertly manufactured, is the only guarantee of a spectacular, durable, and perfectly safe staircase.
Planning a staircase that will become the focal point of your design? Contact our experts to discuss your project and get a quote.
