4 minute read
Design steps to stair safety
Too often design flair can compromise the safety of stairs presenting a risk of injury, or worse. Kevin Underwood looks at the four design characteristics that can make all the difference to stair safety, without compromising the aesthetic appeal.
Passive haus. Photo: David Smith
When we speak of stair design for dwellings, usually the pressing questions relate to budget, time frame and ease of installation. For one-off bespoke staircases, intricate design details and material specification can be added to the list. But all of these should be considered alongside stair safety, which is paramount.
Stairs present a risk of injury through slips, trips and falls. In the UK it is reported that there is a fall on stairs every 90 seconds1 and, on average, there are 665 deaths in England and Wales caused by a fall on or from steps or stairs each year.2 While personal and behavioural factors can certainly play a part, such as decreased balance or carrying objects up the stairs, the risk of accidents can be reduced by attending to those characteristics of a staircase that affect a user’s ability to use the stairs safely.
Consistent rise and going
It is important to understand that when climbing or descending stairs, the brain subconsciously determines the movements that the legs and feet need to take based on experience of the first couple of steps. This makes us all vulnerable to trips and falls if the height (rise) and depth (going) of each step is not consistent, as these variations are unexpected and will often not be recognised by the user. To help prevent accidents due to this inherent human instinct, each step’s rise and going should only vary by + or – 1% throughout the staircase.
The going of a stair, its depth, can significantly affect a person’s ability to travel up or down the stair safely. If the going is 30cm or more, users are less likely to overstep. However, for those steps that cannot be as deep as this, surface finishes that offer high slip resistance should be used to reduce the risk of an accident.
Handrails
Handrails should be provided to offer stair users added support when needed – and when combined with balustrade (guarding), can also be used as an attractive design feature. Often handrails, even when provided, >>
are not used and many stair users even deem them unnecessary. But they are vital for safety – especially for those who are more vulnerable, such as the elderly.
If someone loses their balance when climbing stairs the handrail provides a crucial point of contact for them to grasp, to prevent a fall. For this reason, the handrail needs to be positioned so that it can be easily reached from all points on the stair.
Guarding
Staircases should also be designed with suitable guarding to protect users from falls from the side of the stair for all steps at a height of 60cm or more from the floor. The material used for the guarding should be strong enough to withstand someone falling into it and the guarding should be high enough to prevent anyone falling over it. To reduce the risk of accidents in environments where children under 5 may be using the stairs, all gaps in the guarding should be less than 10cm to help stop them becoming trapped. The guarding should also be designed to prevent children climbing, for example, they should not have horizontal rails.
Beech Hill spiral staircase. Photo: David Smith
Surface finish
The finish of a staircase can be the final touch for a breathtaking design, but it can also significantly influence the user’s ability to use it safely. Wet or dusty surfaces, worn or thin carpets and the various types of hard flooring can all play their part. So when designing the staircase, the slip resistance of the material should be considered. If the depth (going) of the step is 30cm or more users are less likely to overstep, but for those steps with less space for the foot, materials with sufficient slip resistance should be specified. >>
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Aspen House. Photo: David Smith
About the author
Kevin Underwood Technical Director BWF
Further information
Further guidance on the design and specification of domestic stairs can be found in the Design Guide for Domestic Timber Stairs, produced by the BWF Stair Scheme. This design guide not only covers legislation and standards, but also provides authoritative advice on how a staircase in the home should be designed and set out, to ensure safety and to reduce commonplace concerns such as squeaks and bouncy stairs. In addition to safety in the design of staircases, careful consideration must also be given to installation. The BWF Stair Scheme has published the Installation Guide for Timber Stairs and is soon to launch an interactive learning tool covering stair installation.
For more information, visit: https://stairs.bwf.org.uk
