Spiral glass staircase: radius, support, price
The most complex glass-staircase config. Minimum radius, central column vs wall-mount, real cases.
Spiral is the hardest thing to make in glass. Bent treads with R600+, precise SP 118 geometry, central column or wall cantilever. 1.5–2× the price of a straight stair.
01Two constructions
Central column
Steel tube Ø140–200 mm at the centre, treads bracket-fixed to it. Minimum outer-edge radius 80 cm. Standard for small-home spirals.
Price: from 64 000 ₽ per step + 38 000 ₽ for the column.
Wall-cantilevered
Treads anchor only to the load-bearing wall. No central column — floating steps around the curve. Much pricier, much better looking. Minimum outer radius 1.2 m.
Price: from 78 000 ₽ per step.
022026 prices
| Config | Steps | 2026 price |
|---|---|---|
| 360° / 2.7 m, central column | 14 | from 934 000 ₽ |
| 360° / 3 m, central column | 16 | from 1 062 000 ₽ |
| 360° / 3 m, cantilever | 16 | from 1 248 000 ₽ |
| 180° / 1.5 m (half-spiral) | 8 | from 562 000 ₽ |
| + LED edge lighting | — | +8 000 ₽/step |
| + glass side handrail | — | from 22 000 ₽/lin.m |
Biggest mistake — trying to "simplify the spiral" to a 60 cm outer radius to save space. SP code violation (foot doesn't fit on 250 mm centre-step) and a year of family use guarantees injury. Minimum spiral diameter: 1.6 m.
03This service at REAL GLASS
If you've read this far, the topic is probably relevant to a real project. We make glass staircases in-house in St. Petersburg, with a measure within 1–3 days, 1-year warranty and a fixed contract price. All numbers in this article come from our actual 2026 quotes.
For a project-specific estimate — see the service page or request a free on-site measure.
