For more information about Spiral Stairs
or to arrange for a survey & quotation
Phone : 0116 235 5330
or email your plans to design@bossstairs.com
Spiral Staircase
Cornwall
Oak Spiral Staircase
Cornwall
Spiral Staircase
Cornwall
Spiral Staircase
Cardiff Wales
Spiral Staircase in Limed oak
Cardiff Wales
Spiral Staircase
Cardiff Wales
Stone Spiral Staircase
Leicestershire
Stone Spiral Staircase
Leicestershire
Stone Spiral Staircase
Leicestershire
Spiral Staircase
Converted Victorian Chapel
Spiral Staircase in oak
Converted Victorian Chapel
Spiral Staircase
Converted Victorian Chapel
Spiral Staircase in Walnut
Commercial Property Birmingham
Spiral Staircase in Wenge
Restaurant Slough Berkshire
Spiral Staircase in Ash
London
So what exactly do we mean by the term ‘Spiral Stairs’
and how do spiral staircases differ from helical staircases?
Spiral stairs wind around a newel or the central pole. They typically have a handrail on the outer side only, and on the inner side just the central pole. A squared spiral stair assumes a square stairwell and expands the steps and railing to a square, resulting in unequal steps (larger where they extend into a corner of the square). A pure spiral assumes a circular stairwell and the steps and handrail are equal and positioned screw-symmetrically. A tight spiral stair with a central pole is very space efficient in the use of floor area. Spiral stairs have the disadvantage of being very steep - only if they are tight or are otherwise not supported by a centre column. This is because of two reasons; the wider the spiral, the more steps can be accommodated per spiral. Therefore, if the spiral is large in diameter, via having a central support column that is strong and a special handrail that helps distributes the load,each step may be longer and therefore the rise between each step may be smaller. Otherwise, the circumference of the circle at the walk line will be so small that it will be impossible to maintain a normal tread depth and a normal rise height without compromising headroom before reaching the upper floor. To maintain headroom some spiral stairs have very high rises to support a very short diameter. These are typically cases where the stairwell must be a small diameter by design or must not have any centre support by design or may not have any perimeter support. Many spirals, however, have sufficient width for normal size treads (8 inches) by being supported by any combination of a centre pole, perimeter supports attaching to or beneath the treads, and a helical handrail. In this manner, the treads may be wide enough to accommodate low rises. The term "spiral" has a more narrow definition in a mathematical context, as a mathematical spiral lies in a single plane and moves towards or away from a central point. The mathematical term for motion where the locus remains at a fixed distance from a fixed line whilst moving in a circular motion about it is "helical". The presence or otherwise of a central pole does not affect the terminology applied to the design of the structure. Spiral stairs in medieval times were generally made of stone and typically wound in a clockwise direction from the ascender's point of view to place attacking swordsmen, who were most often right-handed, at a disadvantage. This asymmetry forces the right-handed swordsman to engage the central pike and degrade his mobility compared with the defender who is facing down the stairs. Extant 14th to 17th century examples of these stairways can be seen at Muchalls Castle, Crathes Castle and Myres Castle in Scotland. Helical or circular stairs do not have a central pole and there is a handrail on both sides. These have the advantage of a more uniform tread width when compared to the spiral staircase. Such stairs may also be built around an elliptical or oval platform. Both double spiral and double helix staircases are possible, with two independent helical stairs in the same vertical space, allowing one person to ascend and another to descend, without ever meeting if they choose different helices. Fire escapes, though built with landings and straight runs of stairs, are often functionally double helices, with two separate stairs intertwined and occupying the same floor space. This is often in support of legal requirements to have two separate fire escapes. Both spiral and helical stairs can be characterized by the number of turns that are made. A "quarter-turn" stair deposits the person facing 90 degrees from the starting orientation. Likewise there are half-turn, three-quarters-turn and full-turn stairs. A continuous spiral may make many turns depending on the height. Very tall multi-turn spiral staircases are usually found in old stone towers within fortifications, churches and in lighthouses. Winders may be used in combination with straight stairs to turn the direction of the stairs. This allows for a large number of permutations.