Stairs are the main form of communication between rooms at different levels. All other structures (ramps, elevators) are considered special means of transportation.
The function of the stairs is to ensure the movement of people. This is a guarantee of their safety and comfort. Based on this, in the process of erecting each such design, the masters are guided by the requirements and standards set forth in a special GOST and SNiP.
Elements of the staircase
Despite the huge number of species and types, stairs consist of several main components:
- Stair march (span). This is the name of the inclined structure, which connects the two nearest floors. There is a limitation according to which in one span there should not be more than 12 steps. In this case, the minimum amount is three steps.
- Platform - a horizontally located element, mandatory for stairs from several marches.
- Fencing - this mandatory component of the structure consists of balusters and railings. It is placed along one or two sides of the stairs. The type, height and location of the guards are specified in the standards.
What is a landing and what is its role?
Staircases, the dimensions of which are also regulated by regulatory acts, represent the space between two marches. The construction of the landing is necessary if the height of the linear march exceeds the permissible norm or it is planned to erect two marches at an angle to each other.
The role of the landing is that it becomes a kind of “transshipment point”, an intermediate element with which a rising person can relax. In addition, this component of the stairs is used to organically connect two flights of stairs.
On various stairs (rectilinear, rotary, curvilinear) platforms are placed every 10 to 14 steps. In the case of planning structures for residential premises, the interval may be 15 to 20 steps.
Dimensions of landings
Like many other parameters, the width, depth and material of the landing is subject to regulation. The development of all these rules is based on the safety and comfort of the people who will use the design.
- For each type of staircase there are corresponding landings. Their sizes are calculated based on the average width of a human step.
- Standards note that their width cannot be already steps. In extreme cases, for example, when developing an individual project, the minimum width of the site should be 640 mm.
- To combine two parallel marches, the width of the landing should be at least 130 mm. This is equal to almost two steps of the average person.
- Other sizes of landings (depth and length) are calculated according to the formulas or correlated with the width of the march.
The value of the depth parameter, as a rule, is the sum of the width of the tread and one step:
- Minimum Depth = Step Width + One Step Length
To build a landing during the construction of a linear march, the same calculation principles are used. If it is necessary to increase the depth of large structures, it should be a multiple of the minimum depth.
Features of the platforms of circular stairs or structures with non-standard steps
When building a private house or a multi-level apartment, they often resort to the construction of extremely beautiful (but sometimes not very convenient) spiral or spiral staircases.
It should be noted that such constructions are not recommended as the main ones, because climbing them is not as easy as climbing stairs with straight marches.
The dimensions of the flights of stairs and the platforms of screw and spiral structures are subject to extremely strict control.
In those cases when the flights of stairs are positioned at an angle of 135 to 180 degrees, the sizes of the intermediate platforms can be less than 640 mm.
However, compliance with this size is necessary if it is a site radially divided into two halves, or in the case of the construction of two-level sites. By the way, the difference in height between the two levels of the site should be equal to the height of the step.
The indicated minimum size of the landing (640 mm) is also relevant for circular and spiral staircases with steps of the “goose step” type.
Stairs as a means of evacuation
To regulate the construction of stairs and landings in buildings where a large number of people are often located, GOST and SNiP contain especially strict instructions. This is due to the fact that the dimensions of the stairwells here are determined not only by the wishes of the developer and the designer’s findings, but primarily by concern for the successful and safe evacuation of people in case of fire or other disaster.
The general requirements are:
- Compliance with the dimensions (width and depth) of the sites.
- The absence of excess objects and structures on the stairs with an increased risk of smoke.
- Production of outdoor and emergency stairs from non-combustible materials.
- Compliance with sufficient staircase lighting using natural and artificial light sources (the size of the windows on the staircases and the type of their functioning are regulated).
What should be the flight of stairs and platforms on the evacuation stairs?
Planning for evacuation and rescue activities becomes necessary when building multi-story buildings or public buildings.
Not only flights and landings are subject to regulation. The dimensions (GOST defines the main parameters) of these elements, as well as the dimensions of the corridors that are adjacent to such structures, should not deviate from the norm.
Thus, the width of the march, which can be used for evacuation, should not be narrower than the door facing it. Dimensions of landings and marches:
- For buildings of class F 1.1 (fire safety characteristic for multi-storey buildings where a large number of people are planned to stay or temporary stay), the size is 1350 mm.
- If more than 200 people will be simultaneously on the floors of the building (except the first), then the staircase should be at least 1200 mm.
- In the case when the staircase goes to the workplace of one person, its width from 700 mm is allowed.
- In other cases, this indicator should have an average value of 900 mm.
What are stairs made of?
A large number of materials are suitable for the manufacture of stairs and their important elements (marches, balusters, fences, platforms):
However, staircases made of concrete deserve a separate description. As a rule, this material is used in the construction of multi-storey buildings and public buildings . For private homes, wood, metal, or a combination of several materials (metal with glass, wood with stone) are more often chosen.
Concrete - versatile material
Concrete stairs and platforms between them are often formed from prefabricated elements. Such structures consist of high-grade material (minimum B15), and are also equipped with a metal frame.
The production of reinforced concrete products is carried out by factories and enterprises, the activities of which are strictly regulated, so the developer does not have to worry about compliance with the manufacturing rules. However, the correct assembly and fixation of structures depends only on the qualifications of the master builders.
Concrete slabs of staircases (dimensions are selected taking into account the dimensions of the building and the width of the marches) are used in the construction of brick and concrete buildings, as well as in cases where combined techniques are used.
Their strength, ease of use and wide possibilities for decoration significantly speed up and facilitate the construction process.
Reinforced concrete staircases (dimensions do not affect operational characteristics) are recommended for the preparation of internal and external stairs. However, it should be borne in mind that reinforced concrete products will be able to maintain their properties in the absence of aggressive environmental conditions. The maximum allowable air temperature must not be lower than -40 degrees.
Decoration of landings
The finished concrete stairs installed inside the living room are sheathed with wooden panels, painted or carpeted.
The staircases lined with ceramic tiles, laminate or parquet board serve well and for a long time.
The use of wood or metal as a material for stairs requires compulsory painting of the finished product. Based on the characteristics of the material, the necessary varnish is chosen:
- Simple paints for metal.
- Emulsions and impregnations for wood.
- Special paints for wood of the corresponding breed.
A great way to decorate and improve the safety of the flight of stairs and the landing is to place lighting. Most often, LEDs (individual lamps or tapes) are chosen for this purpose. They are mounted along the railing, around the perimeter of the site or below on the steps.