Antonia Harding of British Spirals & Castings dispels the myth that spiral staircases are dangerous and explains how they can be used effectively and safely in your project.
With their architectural beauty and space-saving benefits, spiral staircases can be the perfect feature in any style of home. However, it’s these qualities that can lead some to worry about the potential safety issues of such a compact yet open design. Does the fact they take up less floor space make them steep and difficult to navigate? Does their openness, although visually striking, increase the likelihood of serious falls and injuries?
These concerns are understandable, but with careful planning that takes into consideration your individual household needs, it is possible to create a staircase that is as safe and functional as conventional straight stairs, without having to compromise on style.
Designing for your needs
As cumbersome as Building Regulations sometimes seem, BS 5395 Part 2 offers clear guidance on how to construct a safe staircase. By choosing a carefully designed bespoke spiral staircase and using a reputable firm with the right knowledge, you can ensure that not only does your staircase comply with all the necessary safety regulations, but also that every element blends seamlessly into your home and lifestyle.
Shape: It is vital to get the geometry of a spiral staircase right. Building Regulations state that a spiral staircase that services one habitable room should have at least 600 mm clear width, from the inside of the pole to the inside of the handrail, with a maximum rise (step height) of 220 mm. These measurements increase to 800 mm wide, or 900 mm in Scotland, if serving two habitable rooms. Evenly spaced treads at a consistent width will create a gentle and steady curve. This will give the spiral its strikingly organic aesthetic and reduce the steepness, making it easier to navigate even when carrying awkward objects.
Indeed, the shape of the spiral can be considered a safety plus in itself as if you lose your footing, you would only fall one or two treads before meeting the balustrade or the spiral handrails.
Materials: One of the first decisions to make when designing your spiral staircase is what it will be made of. There are a variety of materials and finishes to choose from, from powder coated metal to solid timber, or a combination of these options. In addition to allowing you to tailor the staircase to the look and feel you want to achieve, they can offer differing levels of grip. For example, a diamond or grated patterned cast metal tread can help to reduce the risk of slipping; particularly useful when used outside under the British weather.
There are also additional products you can consider to further reduce the risk of slipping. For example, if you prefer the exposed look or your staircase will be outside, transparent anti-slip tread tape adds traction without detracting from the natural quality and beauty of the material.
Risers: A key regulation to keep in mind when choosing the different decorative and structural elements of a spiral staircase is the ‘100 mm sphere rule.’ This states that there must be no gaps greater than 99 mm anywhere on the staircase to stop the risk of limbs becoming stuck, or young children or pets falling through the gap.
This is particularly important to think about when choosing the style of riser. While it is, of course, possible to build a spiral staircase with closed risers as you would see on a standard staircase, for some the beauty of a spiral design is in its light and ‘floating’ appearance. A riser bar – a thin steel bar or a piece of timber planted to the front tread – reduces the gap between each rise/tread to less than 100 mm without compromising on the open look of the staircase. If you have chosen an ornate metal spiral design, you could complement this by using decorative fascias instead of the traditional plain fascias.
Balustrades: Balustrades are another element that are subject to the 100 mm sphere rule. In households with small children – who not only have a tendency to see anything with bars as a large climbing frame, but also use them to hold onto and lean against when using the stairs – it is especially vital to safeguard them from falling through the space in between each balustrade. To comply, you will need two or three balustrades per tread. There is a huge amount of choice in balustrade styles and combinations, making it easy to achieve the feel you want for your staircase.
In some cases, having three balusters per tread could make the staircase feel too heavy. Instead, infill panels can be used to replace two of the three balusters on the tread. They are a wider type of baluster that come in a variety of styles to suit the look you are trying to achieve. Another increasingly popular alternative to balustrades is to use glass infill panels. While these do not offer the same places to grab as balustrades, they are a great way to close off the sides of a spiral staircase without stopping the light from getting through.
Handrail: The handrail is the most obvious safety feature on a staircase. Regulation states that the handrail height on a spiral staircase should start 900 mm above the stair tread. This is to ensure that it is at an easily accessible height along the entire length of the staircase. The handrail itself should be sturdy and allow for whole hand grip, to offer more protection from falling and to enhance the tactile experience of using the staircase.
The handrail on any landing balustrade that is needed also needs to be at least 900 mm high in a residential application.
Landing plates: Landing plates should be used on the upper floor to create a safe and smooth exit and entrance to the staircase by keeping the staircase and floor at a constant level. A landing plate of some kind is required to connect the centre pole of the staircase to the finished floor level. These tend to be in the same design as the staircase but can be built in by others as a continuation of the floor if preferred. If your staircase is particularly high, they also can be incorporated as a rest stop part way up the staircase, which will be useful for elderly people or children.
If you have your heart set on a spiral design but still feel uneasy, don’t be afraid to ask manufacturers if you can go and try out some of their designs to see the quality of the materials and construction for yourself. While being safe on the stairs eventually comes down to common sense (we are all guilty of sometimes piling the bottom stairs with stuff we need to remember), having a design that’s safe for you and your family, and right for your home, can make all the difference.
Antonia Harding is director at British Spirals & Castings