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.
- Materials.
- Design.
- 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.
- Landings.
- 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.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Introducing or next Guest Editor Arun Baybars
Practising architect and design panel review member.
Quick summary by size, shape, test, material, use or bonding.
Types of rapidly renewable content
From forestry to agricultural crops and their by-products.
Terraced houses and the public realm
The discernible difference between the public realm of detached housing and of terraced housing.
Put digitalisation and sustainability at the core of curricula
Project management educators are urged.
Looking back at the influence of climate events
From a designer and writer: 'There are limits to growth but no limits to development'.
Terms, histories, theories and practice.
Biophilic design and natural light
Letting in the light and natural elements into spaces.
APM Programme Management Conference 2024
Strategies for Success.
Residential takes the reins as contract awards even out
Contracts down, but remain above the last quarter of 2023.
Celebrating Eid and the largest mud-brick building.
Barry Kingscote claims prestigious CIOB CMYA Award.
The British Mosque: an architectural and social history
The story of some 1,500 mosques or more in Britain.
Heat pump refrigerants, efficiencies and impacts
R12 to R1270 what are the differences?
Global heat pump market in 2023
Challenging times with positive but modest outlook.
Beyond the infrastructure pipeline
Opportunities and chokepoints.