How do you get from one floor to the next? The staircase is still the most suitable building element for connecting two floors or connecting the basement and attic. The core requirements for the staircase are maximum utility with minimum use of floor space. Although space-saving spiral staircases are sufficient for people, they can be very impractical for transporting furniture. In order to find the right staircase for every purpose, the history of building has therefore produced numerous solutions.
A staircase connects two floors of a building. In order to get from one building level to the next without technical aids, stairs have been the proven structural element for thousands of years. Stairs have always had a conflict of goals, although they are excellent for this purpose, but on the other hand they also take up a lot of space. The more compact a staircase is constructed, the more limited its usefulness becomes. This area of tension has led to numerous types and shapes of stairs from which a customer can choose today. The most common types and design features of stairs are presented here.
Difference between shape and species
The shape and style of a staircase is not the same. In fact, numerous combinations can be made from the shape and type of a staircase. Another distinguishing feature between the stairs is their material. This is essentially limited to steel, artificial/natural stone or wood, but they are not to be considered further in this list.
The shape of a staircase refers to its top view. It is largely responsible for the practical utility value and for the space consumption of the staircase. There are five basic shapes for stairs to choose from, which in turn can be combined and varied. The basic shapes of stairs are:
- Straight stairs
- platform stairs
- spiral staircases
- spiral staircases
- polygonal stairs
Straight stairs are the simplest stair construction. They consist of a straight, even flight of stairs in which the floors are connected to each other without interruption and without branches. Stairs in particular take up a lot of space. They can be constructed in any width, which makes transporting bulky loads particularly easy.
A space-saving variant of the straight stairs are the space-saving stairs. In this case, the steps intertwine. This specifies which foot must be used to climb the stairs first. They make good attic folding stairs, but are not recommended for regular use due to the risk of falling.
Landing stairs consist of at least two individual segments of straight stairs that are connected to each other by landings. At each landing, the direction of the stairs can be changed. A permanent change of 90° is usual. If only one change of direction is carried out on the stairs, one speaks of a 1/4 spiral staircase.
If two angles are installed, one speaks of a half-turn staircase or a U-staircase. This is the standard stair shape in apartment buildings. They allow loads to be dropped off when moving. This makes transporting bulky furniture or equipment very safe. Platform stairs offer maximum utility. In addition, they can be produced particularly quickly and inexpensively by using uniform components.
Spiral staircases allow curves to be built into the flight of stairs. They offer a space-saving and elegant way to change the direction of the stairs when changing floors. Their construction is very complex, but can be individually adapted to the requirements of the building. Curves of 90 – 180° are common. Spiral staircases can also be combined with platforms.
Spiral staircases are circular staircase shapes. They are particularly space-saving. However, their width is always limited by design. They are hardly suitable for transporting bulky loads. Spiral stairs are used to climb towers or as emergency stairs for people. They are also often used indoors in multi-storey apartments. However, when they are used, there should still be a second access to the upper floor. Spiral staircases in family houses are well suited as an additional, convenient connector due to the minimal space requirement. However, they can only be used to a very limited extent as fully-fledged connectors for floors.
In the case of polygonal stairs, the turn is not created by radii, but by angled branches. They are well suited for stairs with a pronounced eye. The eye of a spiral staircase is its central open space. In the past, polygonal staircases were often found in hotels because an open elevator could easily be accommodated in their middle. Today, polygonal stairs have lost some of their importance.
types of stairs
Stairs differ in their type by their static construction. As in the form, stairs are also in their type in a conflict of objectives: the highest possible static load capacity must be combined with the lowest possible consumption of material. A staircase is a constantly dynamic place that is only ever used briefly and temporarily. In addition to the use of space, stairs should therefore also be visually aesthetic and as undominant as possible in a building concept. This leads to numerous variations in the static construction.
A staircase consists of steps that must be connected to the ground. The nearest wall, a separate substructure, stable stringers or even just the risers can be used for this. Even the risers can be replaced with thin bolts, creating a particularly delicate and airy staircase. However, the more filigree and lighter a staircase is constructed, the less resilient it is. The resilience can be compensated to a certain extent by the choice of high-quality materials. However, this is only possible to a limited extent and is always a question of cost. Elaborate, filigree and lightly constructed stairs are therefore mostly intended for indoor use, where a staircase should also have a special visual function.
- hanging construction
The step is the central element of the stair function. It must be sufficiently wide and stable to safely accommodate people and loads.
The riser connects the treads together. It has static and optical functions. It is also important for safety by preventing legs and feet from slipping.
The stringers of a staircase are the side elements between which the steps are attached. They can be provided on site or specially made for the stairs. In the case of stairs hinged on one side, the wall forms a stringer of the stairs.
Vertical support elements or profile structures running lengthways under the stairs can be used as the substructure . With Q or R profiles (profiles with a square or rectangular cross-section), high-strength and very heavy-duty self-supporting stairs can be produced. However, producing these substructures is very complex due to the pieced and welded construction.
In the case of suspended constructions , the support loads of the steps are absorbed by ropes or rods attached to the ceiling, the parapet or the handrail. Suspended constructions are rare and difficult to implement due to the vibration of the steps. Nevertheless, they are useful in some cases due to their security against falling off to the side.
The parapet offers a closed lateral support, which is intended to prevent a lateral fall from the stairs. Large glass panels are often used for balustrades indoors. These offer maximum protection with the greatest transparency. The balustrade can be solid as well as very filigree with steel or wood constructions.
The main purpose of the handrail is to be able to hold on while climbing the stairs. In some cases, for example in the case of suspended staircases, the handrail can also have static tasks.
Depending on the material and construction of the staircase, the individual elements can play a more or less important role in the statics of a staircase. Different elements of the attachment are often combined with each other. This results in different basic forms of stairs, which are usually implemented as mixed forms.
Cantilever stairs can be found both in the particularly solid and in the particularly filigree construction. Normal reinforced concrete stairs, for example, are mainly constructed as cantilever stairs. They are cast as a monolithic block that is placed at defined points on the building structure. Cantilever stairs do not require an additional suspension or substructure. Cantilevered staircases can be found indoors as folded work staircases. These are optically very appealing, but not very resilient solutions.
In the simplest case, these are already existing walls of the building. This solution is often found at entrances or basement stairs. The stringer can also be a constructive element of the staircase itself. Steel stairs are often designed as stringer stairs because they are particularly easy to manufacture. Indoors, stringer stairs are often made of wood. A variant of the sometimes mighty wooden stringer stairs are flat stringer stairs. The cheek consists of high-strength GRP. This enables a particularly thin cheek.
In the case of bolted stairs, the risers are replaced by connecting bolts. They are statically very complex to implement and can only be produced with a hanging or substructure. But they offer interesting optical effects. However, the missing riser is always an increased risk of accidents. This type of stairs is divided into bolt stairs and load-bearing bolt stairs. In the case of load-bearing bolt stairs, the bolts have additional static functions.
With cantilever stairs, the steps are only attached to a wall on one side. They “collar out” and hang freely in the air on the other side. The cantilever stairs appear technically very simple, but are very difficult to implement. The stair step hanging on one side of the wall creates a leverage moment that can only be dissipated permanently and safely with great effort. This is partly achieved by massive steps, which in turn generate a high leverage moment through their own weight.
In any case, cantilever stairs require a high-strength wall to which they are attached. Even brick masonry cannot be sufficient for this. The ideal wall for cantilever stairs therefore consists of reinforced concrete with a wall thickness of at least 24 cm. Cantilever stairs are very stylish. However, due to the lack of lateral support and the open design without risers, they are also very dangerous. Their use should therefore be carefully considered. If a cantilever staircase is to be supplemented with a railing for reasons of safety, then it is also very easy to find optically similar but significantly more stable constructions for the staircase.
These basic types of stairs are often combined in practice. Stairs are attached to a wall on one side due to the economical spatial planning. This means that the cantilever stair is part of the construction of many stair shapes. This can now be statically relieved by a substructure with the static properties of a cantilever staircase. The self-supporting properties can also be provided by a stable handrail or parapet, to which the steps are attached. The combination options are so diverse that the right staircase construction can be found for every application.
Which stairs to take?
The choice of stairs must be weighed up in the triangle between the parameters of appearance, statics and function. A light and airy look with high aesthetic standards and an additional desire for static resilience always results in the choice of particularly complex construction and high-quality materials. It is therefore worth planning a staircase very carefully. With a certain willingness to compromise when adjusting the parameters, the budget can be significantly relaxed.
With all the wishes for the optics, however, one should not neglect safety. Lateral support provided by a sturdy handrail, protection against slipping sideways or between steps, or a protective parapet can maximize stair safety. You get used to the optics relatively quickly. It’s good if security isn’t neglected.
Tips for speed readers
- Only plan spiral staircases as additional staircases
- Cantilever stairs are statically very complex
- straight stairs can be made quickly, safely and easily
- Glass balustrades provide maximum security with the best optics