In terms of functionality, ladders are necessary for vertical movement, for example, from one floor to another.
By appointment and use, all types of stairs are divided into:
- the main (marching);
- central-entrance (or front);
- In-apartment (located in multi-level apartments or in a private house);
- park and garden.
roofing (installed on pitched roofs, used for safe installation and maintenance);
emergency evacuation (for emergency and rescue operations);
service (installed for access to the basement and attic rooms);
Screw staircases are often intra-apartment, because they are installed in a multi-level apartment or in a private house. An interesting solution will be the installation of a spare evacuation spiral staircase on one of the exterior walls of the house. The concrete spiral staircase will become an interesting and functional attribute of the exterior facade of the house. Screw stairs are installed in the basement and attic rooms: they occupy less space than the flight stairs and look more original.
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 the conditions of its operation.
Variants of stairs from different materials:
- from natural and artificial materials (tiles, granite, marble, granite, etc.);
- metal and steel (copper, steel alloys, aluminum alloys are used, often in the manufacture of metal stairs used art forging);
- concrete (reinforced concrete);
- glass (often combined).
Often the stairs are made of wood, metal alloy or glass. Less often - marble and concrete. Designers create different versions of materials (railings and stairs), often there are combinations of glass and metal, stone and wood, glass and stone, wood and glass, and so on.
The choice of material depends on the style in the interior. Tree - almost universal material, because. suitable for operation in various environments (indoor and outdoor). The tree is well combined with other materials, so it will not be difficult to combine wooden steps and rails from transparent glass, create concrete steps and beautiful forged fences and handrails.
Types of spiral staircases
Of all the diversity can be identified the main types of spiral staircases, their four:
- Stairs with support on the walls. Steps are wedge shaped (narrow from one end, wide from the other). The wide end of the steps is attached to the supporting wall, the narrow end to the support post (you can do without it). These spiral staircases are installed on the second floor or in the basement rooms, most often located in the corner of the room. The fences are only needed on the upper platform.
- Ladder with support on the inner column in the center of the design with cantilever fixation (modular staircase). This binding is called console (or modular), because each of the stages has a node at the narrow end, facing the center. Each node is inserted into another, having the form of a designer. Such models of stairs are most popular in private houses and cottages. It is simple to mount and assemble, and the design ideas for such a ladder are not limited to anything. The modular spiral staircase is absolutely not tied to the wall, so it can be located even in the center of the room. It i
s advisable to install fences along the circumference of the entire staircase.
- Stairs with support on a monolithic central pillar. 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, they can be used both in the apartment and at the dacha.
- Stairs without support on the central pillar and walls. This is the most original design of the spiral staircase, especially for a private building. Designers have come up with a way of fixing the steps of the spiral staircase on specially bent strings or strips (these are the bearing elements of the stairs).
The spiral staircases of the second and third models can be made and installed independently, the modular ladders are very simple to assemble. But the fourth option requires special attention and skill, so it is better not to engage in independent designing, manufacturing and installation, but to entrust this business to professionals.
The presence and absence of handrails, handrails and fences does not depend on the type of construction. For aesthetic reasons, you can refuse handrails, but for safety reasons, experts recommend installing them. Cast iron spiral staircases are often made immediately with handrails.
Spiral staircases in interiors
Different models of spiral staircases look great in any interior - from luxurious baroque to classic Victorian. Steel spiral staircases will be appropriate in both laconic minimalism and expressive fusion style. The spiral glass staircase looks admirably in the interior in the style of high-tech, and the white stone staircase will become an integral part in the Mediterranean interior.
In a private house or multi-level apartment, spiral staircases look more interesting than marching ones. Several advantages:
- Compactness. This is especially important in the apartment.
- Originality. Screw staircases for cottages can be supplemented by a pole in the span or a hill for a quick descent. This idea is very popular with children.
- Design of spiral staircase. Steel, concrete, wooden, glass, plastic, stone, combined - hundreds of spiral staircases. It will not be difficult to find exquisite cast iron handrails that match the color scheme to wooden or concrete steps. You can order original glass fences made of transparent or frosted glass, with a pattern or stained glass. You can leave the handrails or combine them with the fences, you can leave the fences or completely abandon it. In any case, the spiral staircase will look interesting and original in any interior.
- Price. As a rule, standard spiral staircases are slightly cheaper than marching ones.
Dimensions of spiral staircase
Experienced and practical ways the formula of the safest ladder was derived: 2a + b = 600 ~ 640 mm. In this formula, a is the height of the step,
b is the step width, 600 ~ 640 mm is the average step size of the person on the horizontal plane surface.
The width of the step should support the entire length of the foot, on average from 200 mm to 340 mm. The step height should not exceed 250 mm, the height from 150 mm to 200 mm is considered optimal. Given the wedge shape of the steps, at the point of support on the central bearing column, the width should not be less than 100 mm.
The length of the steps depends on the purpose of the staircase:
- less than 80 cm is considered not comfortable even for 1 person, but suitable for fire escape;
- from 80 cm to 100 cm (1 m) will be optimal for stairs leading to the second floor, attic or basement;
- the length of the step from 100 cm and more is considered comfortable for two people.
Standard stairs are most often made with a width of the tread (tread) 300 mm and a height of 150 mm. The width of the step can be increased by hanging the upper step above the lower one. But in this case, the width of the hanging part should not exceed 50 mm if the construction is steel and 30 mm if it is a wooden spiral staircase.
It is important to remember the angle of the spiral staircase. The most secure angle is from 25 ° to 35 °. If the angle of inclination is more than 40 °, then the descent from the spiral staircase will be problematic, and if the angle is more than 45 °, then the descent can only be carried forward by the back (steps too steep).
The opening on the top floor must be at least 2 m, especially if the staircase is the main one and often operated, for example, to climb to the top floor. The length of the steps in this case (if the opening is about 2 meters in diameter) will be equal to 80-90 cm, because a part of the length will be "eaten" by fixing the pillar, rails and fences will be placed. Given the fan-shaped arrangement of the steps and the effect of overhanging the upper steps above the lower ones, no more than 65 cm (650 mm) will be set aside for walking. Secondary options for stairs, used rarely, have an opening of 130-140 cm.
Draft of the spiral staircase: calculations
- The size of the alleged opening of the upper floor:
for the main staircase not less than 2000 mm (2 m), for the "emergency" ladder - 1300 - 1500 mm (1.3 - 1.5 m).
It is possible to build on the width of the opening rather than the width of the opening, based on the width of the march (the value that determines the width of the flight ladder, in our case, the screw, if it is "untwisted").
- The height of the future staircase (the height of the interstorey space).
- Angle of twisting. For the spiral staircase in the middle of the room, angles from 270 ° to 360 ° are most often used.
To build a ladder, you need to determine the number of steps, their length, width and distance between them (the height of the step).
Let's say the height of the ladder should be 3 m, and the width of the march - 90 cm. Let's translate the values in millimeters (mm) for convenience of calculations: 3 m = 3000 mm; 90 cm = 900 mm. The rail will take approximately 100 mm. The overall diameter of the spiral staircase can easily be calculated by the formula: D = 2a + 200 mm, where a is the width of the march of the future ladder, and 200 mm is the diameter of the pillar in the center of the structure (it is not recommended to make it less than 20 cm in diameter). We get:
D = 2a + 200 mm = 2 * 900 mm + 200 mm = 1800 mm + 200 mm = 2000 mm (2 m)
If the height is 3000 mm, and the optimum step height is 150-200 mm, then we get:
3000 mm / 150 mm = 20 steps
3000 mm / 200 mm = 15 steps
If you stay on 15 steps, then you need to climb 14 steps + 15 steps - the top platform. Using the formula 2a + b = 600 ~ 640 mm, we select a larger value - 640 mm, we can calculate the width of the steps:
2 * 200 mm + b = 640 mm
b = 640 - 400 = 240 mm
The step width will be 240 mm, which meets the safety requirements of the stairs.