The advantages of using spiral stairs over circular stairs are:
- Spiral stairs are more compact. You can use it best in places where space is at a premium.
- Spiral stairs are supported by a single pole at its center, which makes it easier to install as compared to circular stairs.
The advantages of using circular stairs over spiral stairs are:
- Circular stairs are relatively easier to navigate. The usability of circular stairs improves as you increase the diameter of the stairs.
- More than one person can walk up or down circular stairs at the same time. As only the outer diameter of most spiral stairs are usable, you cannot use it in places that experience significant traffic or require easy navigation, like fire exits.
While designing spiral stairs, make sure that you balance the following features according to the design requirements:
- Stair Diameter: It is the outer diameter of the spiral stairs. You can choose a practical value by surveying the available space. If you want to make the spiral stairs easier to navigate, choose a larger stair diameter at it reduces the steepness of the spiral stairs.
- Tread Angle: It is the angle that every individual tread makes with the center of the pole. If you want to make the spiral stairs easier to navigate, you can choose a large tread angle as it gives more usable area to each tread. The drawback of using large tread angles is that the available headroom of the spiral stairs reduces.
- Overlap Distance: It is the distance by which consecutive treads overlap each other. If you want to increase the headroom of the spiral stairs, choose a larger overlap distance. The drawback of increasing overlap distance is that the spiral stairs become steeper.
- Number of Risers: If you want to make the spiral stairs easier to navigate, choose a larger number of risers, as it reduces the steepness of the spiral stairs. The drawback of using more risers is that the headroom of the spiral stairs reduces.