Spiral stairs or newel stairs
Instead of an open staircase eye, spiral staircases can also be constructed with a central, continuous tube or column. Then you speak of newel staircases. In contrast to a spiral staircase, the diameter of a newel staircase is usually much smaller, since newel staircases are usually used as stairs for apartments. However, there is nothing to prevent it from being used as a main staircase if the stair diameter is sufficiently large. Also for outside stairs the choice falls gladly on a newel staircase. While steel or stainless steel is used for internal stairs, the choice for external stairs is a galvanized steel newel staircase. A newel or spiral staircase is also known as an “arched staircase”.
- Newel stairs with glass or wooden steps
- Newel staircase with external balustrade
- Newel staircase with steel or stainless steel railing and wooden handrail
- Spiral staircase as foyer stairs for commercial buildings and banks: with generous floor heights and spacious diameter for a pleasant flight width
Spiral stairs in architecture
At the beginning of the planning of a spiral staircase / arched staircase you have to decide which material to choose: wooden stairs, concrete stairs or steel stairs. Alone due to the processing possibilities of steel, the decision is therefore quickly made for a metal staircase. Probably the most common construction method for a spiral staircase is the construction as a stringer staircase – depending on the static requirements as flat steel or box stringer staircase. With the help of CNC-controlled laser technology, the steel stringers are lasered out of a sheet metal plate and then rolled according to the stair shapes. Due to the static properties of steel, the cross-sections can be significantly smaller than the stringers of wooden stairs.
With stringer stairs in open building method a multiplicity of design possibilities are open to you:
- Wooden steps and wooden handrail as a contrast to the steel stair construction
- Glass steps with an anti-slip screen-printed surface: depending on the degree or pattern of the screen printing, this can also have a creative influence. Stairs with glass steps are also called glass stairs
- Steel or stainless steel railing with horizontal or vertical filling bars
- Railing with double flat steel balusters
Likewise, stair constructions with soffit cladding have established themselves as a stylistic element in modern stair construction. For this type of construction, too, the material steel has the best possible properties, so that visually and architecturally sophisticated soffits are possible. Due to the closed soffit, the step construction of these staircases is designed as a folded structure. These so-called folded stairs are then covered with wooden steps.
Spiral staircase as sculpture staircase
A special form of the two stringer stairs in modern design are stringer stairs, where the inner and outer stringer serves as steel balustrade / railing. In this design, the steel steps are welded between the stringers of the staircase as a substructure for the tread covering. In addition to the open construction method, constructions with folded treads are currently becoming more and more popular. Here the horizontal treads are closed by vertical risers. As harmonious contrast usually wood steps in oak or beech are selected as step covering. As upper conclusion for the railing a stainless steel or wooden handrail can be put on when desired. Also constructions with an internal wooden handrail are very popular.
Spiral staircase as single stringer or saw tooth staircase
Apart from the construction as stringer stairs spiral stairs are also designed as single stringer stairs. The substructure for the treads is fastened on the supporting stair rail. The stringer can be in the form of a round tube or be box-shaped or triangular. Usually the spar is constructed in the middle. One speaks then also of central stringer stairs. For this construction of a spiral staircase, steps made of wood or glass are suitable.
Another special form is the sawtooth staircase, which can also be used for spiral staircases. Two sawtooth-shaped cut flat steel stringers serve as staircase construction, on which mostly wooden steps are then placed. The cutting of these sawtooth stringers is done by CNC-controlled laser technology. Stainless steel railings or railings made of steel with double flat steel posts are suitable as railings for single stringer stairs or sawtooth stairs.
Spiral stairs according to DIN 18065
For a spiral staircase, the minimum and maximum dimensions for usable stair flight width, stair gradient and stair tread as specified in the Staircase DIN must not be exceeded or fallen short of due to manufacturing and installation tolerances. These dimensions must therefore be planned in such a way that the values can be maintained in the finished state.