Stairs tread
Regulations for the design and construction of stairs are set out in Part K of the building regulations, and compliant designs are described in Approved Document K - Protection from falling, collision and impact.
The treads of stairs are the horizontal parts which people step on.
The leading edge of the tread is described as the ‘nosing’. In buildings other than dwellings, the nosing should be visually contrasting, and a suitable tread nosing profile, should be used. See nosing for more information.
Steps should have level treads with the rise and going of each step consistent throughout a flight of steps and are in accordance with the table below.
In buildings other than dwellings, risers should not be open to avoid feet or walking aids being caught underneath the tread during ascent, possibly causing a fall or giving occupants a feeling of insecurity. For dwellings, steps may have open risers if treads overlap by a minimum of 16 mm and steps are constructed so that a 100 mm diameter sphere cannot pass through the open risers.
A tapered tread is a step in which the going reduces from one side to the other. Where stairs have tapered treads, consecutive 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.
Alternating tread stairs are stairs with paddle-shaped treads where the wide portion is on alternate sides on consecutive treads. In dwellings, alternating tread stairs may only be used in loft conversions where there is not enough space for conventional stairs and where the stair is for access to only one habitable room and, if desired, a bathroom and/or a WC (although this must not be the only WC in the dwelling).
Alternating tread stairs should; make alternating steps uniform with parallel nosings, have slip-resistant surfaces on treads, have tread sizes over the wider part of the step in line with the table above, should provide a minimum clear headroom of 2 m, should be constructed so that a 100 mm diameter sphere cannot pass through the open risers and should comply with the diagram below.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Not buildings. Happy holiday from DB.
Future Homes Standard: Industry calls for more ambition
As the Government FHS consultation finally closes.
Improving government projects with data and AI
Enabling better outcomes, efficient modern delivery and influential leadership on government projects.
BSRIA Living Laboratory Innovation Challenge
Final days for submission, closing March 29.
Windows, their frames, forms, factors and functions.
The hidden subtleties of U-Value calculations
Different contexts and what to include as variables.
A brief run down with related articles.
Electrical sector calls for safer public EV charge points
Serious concerns about electrical safety in the public domain.
Building Blocks manifesto presented to parliament
Architects Declare call in for support of five critical policies.
The four elements of project management with APM
Analysis, expectations, collaborative communication and partnerships.
City of London launches Heritage Building Retrofit Toolkit
Empowering owners to initiate necessary adaptations.
Guidance on RAAC in listed buildings
Published by Purcell, endorsed by IHBC, SPAB and C20.
Learning from the past.
Reluctance to hire people with criminal convictions revealed
Employing People with Criminal Convictions Report.
Tackling unconscious bias; Women's History Month
Personal reflections, as the last week of March approaches.