Spiral stairs and helical stairs
Spiral and helical staircases can create a sense of light within properties, they can take up less space than traditional stairs, and can create a focal point to a design. They are often available as pre-fabricated kits.
Approved document K, Protection from falling, collision and impact, gives the following definitions.
- A spiral stair is a stair in a helix around a central column.
- A helical stair is a stair in a helix around a central void.
The approved document requires that spiral stairs and helical stairs are designed in accordance with BS 5395-2 Stairs, ladders and walkways. Code of practice for the design of helical and spiral stairs [1984 + AMD 6076, Corrigenda July 2008, C2, C3]. It gives recommendations for the design of internal and external helical and spiral stairs and gives guidance on the geometry of helical and spiral stairs, including:
- Alternative materials, components and methods of design and construction.
- Fire protection and means of escape.
- Load tests.
- Design geometry.
- Typical layouts for stairs.
- Relationship between rise and going.
- Measurement of clear width and goings.
- Maximum gap between column and tread.
- Calculation of going.
- Calculation of clear headroom.
- Structural materials.
- Sizes of stairs.
Helical and spiral stairs involve the use of tapered treads. A tapered tread is a step in which the going (the depth from front to back of a tread, less any overlap with the next tread above) reduces from one side to the other. Approved document K requires that consecutive tapered treads, should use the same going. If a stair consists of straight and tapered treads, the going of the tapered treads should not be less than the going of the straight treads.
 Related articles on Designing Buildings Wiki
Featured articles and news
ZHA win competition to build an Urban Heritage Administration Centre in Saudi Arabia.
Leaps, not steps, are needed to avoid a ticking time bomb, say BRE in response to Farmer Review.
A multi-purpose hall in France covered in a translucent orange membrane.
Winning designs revealed for a rock formation-influenced residential complex in Rennes.
An article explaining the techniques, regulations and environmental impacts of carbon capture and storage.
Watch one of the first documentaries by the acclaimed Adam Curtis, examining the substandard system building of the 1960s.
Take a look at the tech start-up that could transform construction design and communication.
This house in Barcelona uses an innovative new facade tiling system to blend into the landscape.
The origins, evolution and future of Level 3 BIM.
For new and returning Urban Design students, check out our article list divided up into the modules you'll be studying.
Report states that health of urban dwellers could be significantly improved by rethinking transport design.