In terms of functionality, stairs are necessary for vertical movement, for example, from one floor to another.
The material for the manufacture of stairs can be anything: from stone to plastic. The choice of material is determined by the functional purpose of the ladder and its operating conditions.
Of all the diversity can distinguish the main types of spiral staircases, four of them:
- The stairs are supported on the walls. The steps are wedge-shaped (narrow at one end, wide at the other). The wide end of the steps is attached to the bearing wall, the narrow end to the support pole (you can do without it). Such spiral staircases are installed on the second floor or in the basement, as most often located in the corner of the room. Fences are needed only on the top platform.
- A ladder with a support on an internal column in the center of the structure with a cantilever fastening (modular ladder). This fastening is called console (or modular), because each of the steps has a knot at the narrow end facing the center. Each node is inserted into the other, with the appearance of a constructor. Such models of stairs are most popular in private houses and country houses. It is easy to assemble and assemble, and the design ideas of such a ladder are not limited to anything. The modular spiral staircase is absolutely not tied to the wall, so it can even be located in the center of the room. It is advisable to install fences around the circumference of the entire staircase.
- Ladder with a support on a monolithic central column. It differs only in that the steps are attached to a monolithic concrete or metal pillar. Popular cast-iron spiral staircases of this model. Forged spiral staircases are durable, can be used both in the apartment and in the country.
- Staircase without support on the central pillar and walls. This is the most original design of the spiral staircase, especially for a private building. Designers came up with a method of fixing the steps of a spiral staircase on a special way of curved bowstrings or kosoura (these are the bearing elements of the stairs).
Various models of spiral staircases look great in any interior - from luxurious baroque to classic Victorian. Steel spiral staircases will be appropriate in laconic minimalism and expressive fusion-style. The spiral glass staircase looks delightfully in the high-tech interior, and the white stone staircase will become an integral part of the Mediterranean interior.
Spiral staircase dimensions
The formula for the safest ladder was derived in an experienced and practical way: 2a + b = 600 ~ 640 mm. In this formula, a is the step height, b is the step width, 600 ~ 640 mm is the average step size of a person on a horizontal flat surface.
The width of the step should provide support for the entire length of the foot, on average from 200 mm to 340 mm. The height of the step should not exceed 250 mm, the optimum height is from 150 mm to 200 mm. Given the wedge-shaped steps, at the point of support on the central bearing pillar, the width should not be less than 100 mm.
The project of a spiral staircase: calculations
- The size of the expected opening of the upper floor:
for the main staircase not less than 2000 mm (2 m), for the “spare” - 1300 - 1500 mm (1.3 - 1.5 m).
You can not push off from the width of the opening, but from the desired diameter of the stairs, based on the width of the march (the value that determines the width of the mid-flight ladder; in our case, the spiral one, if it is “unrolled”).
- The height of the future staircase (the height of the interfloor space).
- Torsion angle. For a spiral staircase in the middle of a room, angles from 270 ° to 360 ° are most often used.