Spiral staircases are less safe, but they are much more compact than other types and democratic in relation to any interior style, so people often choose them.
This type of staircases is characterized by a variety of shapes and designs. They can be round or polygonal, supported by a post, wall or by a fence and a notchboard. There are many recommendations regarding the choice of vertical spiral staircases. For example, round ones look great in the center of the room, while polygonal ones are usually placed near the wall. But the most important thing to remember is that it is vital to correctly calculate the size of the steps and not to use risers. This recommendation is due to the fact that closer to the support steps are narrower than on the opposite side, so, when ascending, the foot hangs. If the central part is too narrow, when the staircase is equipped with risers, the staircase will be extremely dangerous for ascending and descending. In order to increase safety of its operation, it is recommended to install handrails, which in this case are simply a necessity.
Basic dimensions of spiral staircases:
- Stair flight width: 530 – 1430 mm;
- Turn: up to 360°;
- Riser height: 15 – 20 cm, but it is better not lower than 17 cm, so as not to hit one's head on the steps above the head;
- Number of steps (recommended): 12 per ascending round, while an odd number for the whole staircase;
- Inner handrail diameter: 120 – 320 cm;
- Outer handrail diameter: 130 – 330 cm;
- Handrail height: 90 – 120 cm;
- Comfortable and safe tread width is 28 cm, but in spiral staircases tread width of 20 cm is allowed along the outer edge and tread width of at least 10 cm at a distance of 15 cm from the inner edge.
The accurate calculation of a spiral staircase is a troublesome task, requiring knowledge of several formulas and basic design knowledge. It is difficult to master this on one's own – and expensive. After all, an error in the calculation will necessitate replacing the staircase. Therefore, we recommend you to order an individual design from us, and, if you wish, you can participate in the development of your interior decor.