A floating staircase looks like the treads are suspended in mid-air with no visible support. The engineering is anything but invisible — every tread is anchored to a hidden structural system that quietly carries the load. Done well, the result is the most sculptural element in a modern home.
How floating stairs are engineered
Three structural systems do the heavy lifting. Each gives the stair a different look and budget.
- Mono stringer (central spine). A single steel beam runs underneath the centre of the treads. The cleanest look from the side; the spine is still visible from below.
- Cantilevered treads. Each tread is bolted into a structural wall via a steel pin or plate buried inside the wall. Truly floating from every angle — and the most demanding to build, because the wall has to be engineered for the load before plaster goes on.
- Hidden side stringer. A steel stringer is tucked behind a wall or inside a glass balustrade. Cheaper than cantilevered, almost as clean.
Oak vs steel: choosing materials
The structural skeleton is almost always steel. The choice is what you wrap it in.
- Solid oak treads — warm, classic, ages well. Best paired with a hidden stringer or wall-mounted cantilever to keep the wood as the visible element. Expect 40–60 mm thick treads for stiffness.
- Exposed steel — folded plate or laser-cut treads, powder-coated. Industrial, minimal, easy to clean. Pairs naturally with glass balustrades.
- Engineered timber on steel — a steel tread with a timber veneer top. Combines the slim profile of steel with a warm walking surface.
Safety and code
Floating stairs follow the same rules as any other residential stair, plus a few extras:
- Maximum gap between treads of 100 mm (so a 100 mm sphere cannot pass through) — required in most jurisdictions for child safety.
- Handrail on at least one side, 900–1,000 mm above the tread nosing.
- Balustrades minimum 1,000 mm high, with infill that resists a 100 mm sphere.
- Each tread engineered for a point load of at least 1.5 kN at the unsupported edge.
- For cantilevered designs, the host wall typically needs reinforced blockwork or steel framing — this has to be designed before the wall is built.
Typical price ranges
Floating staircases sit at the premium end of stair pricing because of the structural engineering and site work involved. Ballpark figures for a single-flight residential stair (14–16 treads):
- Hidden side stringer + oak treads: from ฿180,000
- Mono stringer + oak or steel treads: from ฿240,000
- True wall-cantilevered with glass balustrade: from ฿350,000
Final price depends on tread count, finish, balustrade type, and any structural changes to the host wall or slab. We quote per project after a site visit.
Is a floating staircase right for your home?
They work best in double-height entries, open-plan living spaces, and any room where the stair is on display. They are less suited to tight, closed stairwells — the whole point is the visual lightness, and closed walls cancel it. If you have the space and the budget, few elements transform a modern home as much as a well-designed floating stair.
Design your floating staircase
Try the Stair Builder to preview finishes, then send us your space and we'll come back with a structural concept and a fixed quote.