In order for the staircase structure to be safe and easy to use, it is necessary, during its design, to adhere to the requirements of regulatory documents. Calculations are made according to SNiP - stairs in residential buildings, steps and fences must be of appropriate dimensions. It is necessary to take into account all the factors affecting the staircase structure, its functionality, as well as reliability. An important point is its appearance, definition of style and structural load. In addition, it is worth considering the age of people who will live in the house and pay attention to the safety of movement of children.
Primary requirements
The planning of the staircase structure begins at the design stage and preparation of documentation. To do this, determine the location of its location, the height of the room, the available area, maximum loads, then select the possible structures and materials, then make the necessary calculations. All this is done before the start of work on the construction of the house - in the drawings and in explanatory notes, called technical documentation. Installation of structures, including staircases, is carried out only after the final approval of the project by the customer.
Ladder calculations must be made in such a way as to exclude the possibility of:
- destruction and damage that can lead to termination of operation;
- the appearance of cracks and deformations affecting safety;
- non-compliance with the standard dimensions of structural elements.
According to the requirements of the relevant SNiP, stairs in residential buildings located between the floors of two-level apartments cannot have a march width of less than 0.9 meters, and a slope of less than 1: 1.25. The same standards are provided for basement and basement floors. Marches installed on the stairwells of sectional buildings have slightly different parameters. Their width should be no less than 1.05 meters, and the slope should be no more than 1: 1.5 for two-storey buildings or 1: 1.75 for three or more storey structures. The SNiP states that the minimum width of the march of the corridor staircase should be 1.2 meters or more with a slope of 1: 1.75. It should be noted that the width of the march is the distance between the railing, or the enclosing structure and the wall.
The norms also establish that with a difference in the levels of the base of the floor, the staircase can have at least three steps, and the interfloor march, with the exception of spiral staircases, can have no more than 18 rises. With a larger number of treads, intermediate platforms must be installed.
A very important indicator, which is also determined by regulatory documents, is the minimum height from the step to the ceiling. It must be at least 1.90-2.00 meters. A shorter distance will cause inconvenience when moving people who are taller than average.
Sizes of steps and features of fences
Ladder requirements are set out in two main documents:
- SNiP 2.08.01-89 * "Residential buildings";
- SNiP 2.08.02-89 * "Public buildings and structures".
The regulations stipulate that the dimensions of the steps within the same march should not differ from each other. This is a necessary requirement for the safety of movement of people. When going down or up, a person involuntarily puts his foot at the distance that preceded his next step. Therefore, at different heights or widths of the steps, he may stumble and get injured.
Designers consider the most optimal riser height for intra-apartment stairs to be 150 mm with a tread width of -300 mm. According to the norms, it is allowed to increase the riser up to 200 mm, but it cannot be made below 120 mm. The width of the treads can be reduced to 250 mm, although for mansard and basement stairs it is allowed to make a step depth of 200 mm. Wedge-shaped, or run-in, treads on the narrow side should have a width of at least 100 mm, and in the middle - at least 250 mm. All these dimensions are provided in the current regulatory documentation.
Staircase design issues
The type of staircase and its location is determined based on the purpose of the building or room in which it is to be installed.
When designing stairs, as a rule, the following basic conditions and requirements are taken into account: what type of movement the stairs should provide, while being safe and comfortable; what is the difference in levels; what size and what shape there is space for placing the stairs; what construction technology is applicable in these conditions; where and to what extent ladder structures can be supported; the loads that the ladder will perceive during operation must also be taken into account; as well as what aesthetic requirements the staircase should meet, depending on its functions and the surrounding interior.
Having chosen the type of staircase, its parameters are determined, namely: the number of flights, the useful width, the length of the horizontal laying of each flight, the number and length of landings.
Requirements for stairs are contained in a number of regulatory documents, we will cite excerpts from some.
Determines that the number of ascents in one flight of stairs or on a difference in levels should be at least 3 and no more than 18. The smallest width and the greatest slope of stair flights should be taken according to the table.
According to the number of ascents in one flight between platforms (with the exception of curved staircases) there should be at least 3 and no more than 16. In single-flight staircases, as well as in one flight of two- and three-flight stairs within the first floor, no more than 18 lifts are allowed. The width of the staircase in public buildings should be at least the width of the staircase exit from the most populated floor. As a rule, spiral staircases and run-down steps, as well as split staircases, should not be provided on escape routes.
For architects, it is taken for granted that the design of stairs should be carried out at the design stage of the entire building as a whole. But practice often turns out differently.
Designers and builders working in two-story apartments, private homes, or split-level offices often face the same problem. Customers remember that stairs are needed only during the period of finishing work, when the general construction work has already been completed. But the stairs are structural part of the building... And only at the design stage of all parts of the building as a whole, it is possible to competently solve planning problems, as well as determine ways of attaching stairs to load-bearing structures, determine the size and location of openings in the floors. At the same time, comply with the requirements of regulatory documents on the slope, the width of marches and platforms, the number of feet in the march, loads, etc., and also ensure the convenience of using the stairs.
And only having determined for himself the range of creative freedom, the designer can begin to solve aesthetic problems. Fulfill the wishes of the customer regarding the choice of style, material, color scheme, etc.
Only by linking the stairs with the general constructive, planning and aesthetic solution of the entire structure, it is possible to create truly comfortable, safe, beautiful, durable and economically viable structures. A deviation from this rule will result in additional material costs for the customer at best (you will have to use ineffective, expensive design solutions), or you will have to pay with the inconvenience of operating the stairs, which will turn out to be too narrow, with too much slope or with inconvenient steps.
Safety
The staircase is a high-risk area. Therefore, when designing, special attention should be paid to the steepness or slope of the stairs, fences, lighting, the location of the sites, the size of the stairways.
Permissible slope a flight of stairs is determined based on regulatory documents (see above). In this case, the slope should be constant and should not change along the middle line of the flight of stairs. The height of each step must be exactly the same; unequal step heights are the cause of many stair injuries.
Fencing must withstand a lateral load of about 100 kg so that an adult can safely lean on them. The distance between vertical railing posts should not exceed 150 mm, and if there are children in the house - 120 mm.
If there are children in the house, it is also better to make stairs with a riser ("deaf"), because the height of the steps is usually at least 15-17 cm, and the child can get injured if he gets between them.
Special attention should be paid to lighting stairs, you need to think in advance so that the switches are accessible. The first and last step should be especially well lit. It's good if the light and shadow contrast sharply on the tread and riser. As a result, the border will become clearly visible, because most injuries occur due to the slipping of the foot precisely from the edge of the step. Convenient is the system that automatically turns on the light for a few minutes, enough to go up or down.
When calculating the stairs, you must take into account the height between the steps and the ceiling (edge \u200b\u200bof the slab, beams, etc.). For ease of movement, it should not be less than 2 m. This requirement also determines the size of the staircase.
The safety of the stairs also depends on the material from which the steps are made. If the staircase is tiled with polished stone, then an additional anti-slip carpet is required to be fixed to the steps. Special step mats are used not only for stone steps, they can be fixed to steps of any material. They not only prevent slipping, but also protect the ladder, extending its life. Rugs come in different materials: sisal, virgin wool, polypropylene, polyamide or rubber. Each mat is firmly fixed on any surface, the base of latex rubber does not allow sand, dirt, water to "seep".
Staircase design, its appearance, comfort and safety are essential for any home. A successful staircase design increases the overall comfort level of people who will use it in the future, and also affects the level of ergonomics of the room. Considering the importance and significance of the structure, almost all of its elements are subject to regulation at the legislative level: the width and length of the span, the size of the fences, the number and height of stair steps (GOST and SNiP).
The value of timely calculation of parameters
Basic structures are calculated even at the stage of developing a house project. Width and height allow builders to calculate the most important parameters of the future building.
Often, when developing a staircase project, they are guided by the current norms and the wishes of the building owner. Compliance with administrative documents regulating construction and repair work is mandatory. After all, drawing a beautiful, amazing staircase is half the battle. The structure must be functional, reliable, comfortable and safe.
Ladders to destinations or educational institutions require particular attention.
How exactly staircase construction is regulated
The documents that contain standards, norms and rules, in accordance with which all stairs must be erected, are GOST and SNiP.
For stairs made of concrete and reinforced concrete, there are GOST 8717.1-84 and 8717.0-84. The latter document also applies to stairs made of metal structures.
Their individual points describe how high the marches should be, how many steps should be placed in them and what height they should be done. Also, the angle at which the flight of stairs is placed, the width of the site and the type of fences are discussed.
Some sizes are given with specific values, others represent a range within which master builders can choose the numbers that suit them.
What does "optimal stair slope" mean?
The angle at which the staircase will be located in a private house, multi-storey apartment or public building is the recommended value. The minimum angle is 20 degrees, the maximum is 50 degrees.
A smaller angle indicates that the staircase is low, meaning it is shallow. Of course, it is quite easy to climb such steps and the risk of falling is reduced, but such a structure turns out to be many times longer and takes up much more space. Often, designers urge owners to save space by shortening the length of the stairs. GOST sets the maximum permissible angle of inclination at 50 degrees, since steeper steps are unsafe for a climbing person.
However, there are exceptions, such as the installation of stairs to attics and basements. Steep stairs may be allowed here due to their infrequent use and limited space.
Optimal (for a private house) is a flight of stairs inclined at an angle of 30-35 degrees. This range of indicators corresponds to the natural rhythms of human movement.
What data are taken into account in the process of project development
The most important parameters affecting the staircase are:
- Height of each floor.
- General areas of the internal premises.
- Layout of windows, doors and openings.
- The shape and features of the walls of the rooms (niches, ledges).
These data, which are determined from construction drawings, affect the height of the steps of the stairs, GOST is also necessarily taken into account. In addition, the figures obtained allow you to see what the total height of the stairs, the length of the flights, the number and size of turning platforms will be.
The existence of the established parameters does not mean at all that the staircase does not need to be calculated. Individual projects are necessary, since the final dimensions are influenced by many factors (the material of manufacture of the stairs and fences, the type of their finishing, the materials used in the interior design).
How is staircase (GOST) calculated?
The angle of inclination of the structure depends on how many steps there will be, on their height, as well as on the distance between them.
The standards define administrative documents - GOST and SNiP. The height of the steps of the stairs can be from 12 cm to 22 cm. The choice of a specific size is influenced by the location of the structure and its purpose. For those stairs that are used intensively and often, it is recommended to choose a value of about 14.5-17.5 cm.
Speaking about the depth of the tread (the horizontal plane on which a person steps), its optimal indicator should be indicated: the allowed range is from 25 cm to 40 cm.However, the most convenient are the steps, the width of which is 30-37 cm.
The rationale for these values \u200b\u200bis the size of the average person's foot, as well as the width of his stride. If, for some reason, the optimal parameters cannot be applied or the planned slope of the stairs prevents the placement of steps of such dimensions, the project developers reduce the depth to 14.5 cm. At the same time, they provide for a protrusion that increases the depth by two or three centimeters (overhang of the step).
What is a riser and what should be its height
The height of the steps of any staircase directly depends on the size of the riser and the thickness of the step itself. A riser is a vertical element located between two treads.
As already noted, the standard height of the stair step is 14.5-17.5 cm. At the same time, the process of calculating the parameters provides for a mandatory check for convenience and safety. To do this, add the width of the tread and the height of the riser (according to the drawing). If the amount is between 44 cm and 48 cm, then the ladder can be considered safe.
Number of steps
A standard flight of stairs contains on average 12-15 steps. This amount allows most people to safely climb from the beginning to the end of the structure or to the landing.
To determine how many steps the staircase will have, the masters use the following method:
- Calculate or measure the total length of the staircase (the distance from the first step to the floor of the second floor).
- Divide the resulting length by the approximate height of the riser.
- The resulting size is rounded to an integer and recalculated based on the new data.
This algorithm is rather simplified, since many other factors are taken into account in the process of real calculations (the thickness of the floor covering on the first and second floors, the type of staircase itself, the finishing of the steps).
Features of concrete stairs
Today, the choice of staircase construction for many homeowners is facilitated by the existence of ready-made modules made of high-quality concrete (grade at least B15).
Certified manufacturers are engaged in their manufacture, therefore, all requirements of GOST and SNiP are met (the height of the steps of the stairs, their depth and width, as well as the angle of inclination).
The use of such structures greatly facilitates, speeds up and reduces the cost of building stairs. Reinforced concrete stairs are very durable and can be decorated with various materials and techniques, so they are installed both in residential buildings and in public buildings.
Certain aspects of stair design
The height of the steps of the stairs (GOST provides for this) must be the same for all elements of the stairs. This is a mandatory requirement, which is designed to ensure the balance of a person moving between floors.
In addition, experts say that people are more comfortable completing an ascent or descent with the foot with which they started moving up the stairs. Therefore, many designs contain an odd number of degrees.
If the area between marches consists of several levels, the difference in their height should be equal to the step height.
Spiral staircases and their steps
When designing spiral or spiral staircases, designers have to deal with run-down steps. The requirements for their height remain the same as for straight, pivot or combined structures.
However, due to the specific shape of the steps, the depth of the tread and the width of the staircase itself are subject to strict regulation.
This is due to the fact that moving on screw structures is not as convenient and safe as on traditional ones. For this reason, designers are not advised to build such a staircase as the main one.
Often, spiral staircases are used to climb to the attic or as an aid to transportation. True, many modern screw-type structures have a very beautiful design and become the main decoration of the room. To increase the comfort of future residents, their width and height between the steps of the stairs should be as close as possible to the optimal parameters.
Spiral staircases are completely unsuitable for installation in public buildings and educational institutions. They should also be avoided if a person with reduced mobility will live in the house. True, if the owner still really wants to see just such a staircase in his house, he should place all significant objects and rooms (bedroom, kitchen, living room) on the ground floor.
Safety and reliability, durability and convenience of stairs is achieved through adherence to established rules and design standards. In the process of developing a structure, all calculations are carried out taking into account SNiP, which makes it possible to ensure comfortable operation of structures in public buildings or other facilities. This process takes into account all the necessary factors that affect the functionality and performance of the structure. The design is essential, and the design of the appearance of the ladder should be optimally combined with the established norms and requirements for such structures. As a result of an integrated and correct approach, the design of the staircase, platform and fences are safe and reliable.
Basic design standards
The established standards and foundations allow taking into account all the features to achieve the safety and convenience of stairs. Both in public buildings and in a residential building, it is important to comply with the requirements for the dimensions of the structure. In the first case, there are also other features aimed at additional equipping the stairs. The main points of SNiP must be considered when designing flights of stairs, fences and platforms of any type. This approach is versatile and provides a durable, practical and user-friendly design with optimal design.
Before developing a project, it is necessary to determine the location of the structure. After that, calculations of parameters are carried out, design development, design of fences and marches, platforms and additional elements. This process requires a high level of professionalism, because the structure must be reliable and durable. At the design stage, the main and additional standards, GOST and SNiP are taken into account. Such standards impose requirements on stairs and all constituent elements of the structure. For example, building codes are controlled by the following components:
- Height and number of steps and sizes of protrusions;
- The angle of the staircase;
- Width of the march of the structure;
- Parameters and height of fences, availability of additional handrails;
- The height of the space above the marching structure;
- Dimensions of landings.
There are basic design codes that apply when designing stairs located in public buildings or residential buildings.
These rules are general in nature, but must be followed.In this case, planning is carried out at the stage of development of the building project, but it is first necessary to determine the type of stairs, location and main characteristics. This approach will ensure the creation of an optimal design that complies with the SNiP and established standards.
The main requirements for stairs involve taking into account the main parameters of the future structure.
The design process takes into account the area occupied by the stairs, as well as the height of the ceiling in residential buildings or other objects.Considerable attention is paid to the expected load on the structure, the width of the march and the material from which the stairs and fences will be made. The established rules and requirements make it possible to create a reliable, safe and high-quality structure.
General requirements for stairs located in public buildings or residential buildings are as follows:
- The height of the opening above the staircase area, platforms and marches must be at least 1.9 meters;
- One flight can include up to 18 steps, and with a larger number, an optimal-sized staircase is required;
- The height of the handrails and fences must be at least 90 cm, and if there are children in the building, then additional handrails must be installed and the height of the main fence is 1.5 meters;
- The width of the steps is no more than 25 cm, and the height is 22 cm, while the size of the ledge of each step can be up to 3 cm;
- In buildings that have more than one floor, the slope of the staircase should be 1: 1.75, and in a one-story building - 1: 1.5;
- It is important for institutions to equip an outdoor staircase with a ramp for people with limited limb mobility. The width of such an element should be at least 135 cm, and with a double size, a dividing fence, a handrail is required.
Each staircase in public facilities should be as comfortable, thoughtful and consistent with the established norms of SNP 21-01.
In this case, all parameters are taken into account, for example, the width and size of the flight of stairs, which must be at least 90 cm for the free movement of one person.Also, an important factor is the width of the landing of the structure, which must be at least 1.3 meters. Established building codes and regulations allow you to create a reliable, high-quality and safe lifting surface.
Trap structures for multi-storey residential buildings must also comply with norms and standards. All steps must certainly have the same dimensions, and the rails can be standard, with a height of 90 cm. In this case, the maximum lateral load parameter can be at least 100 kg. The number of steps in one march cannot exceed 18, but an odd number is optimal, which makes it easier to move around the structure. The optimum slope of the march is in the range from 26 to 45 degrees. In this case, the distance from the door to the first step is from 1 meter.
Convertible structures and ladders cannot be used as interfloor stairs. Such devices are used for lifting to the attic or in the basement of residential buildings. In any case, compliance with rules, regulations and other requirements is essential.
It is important to consider every detail in the planning and design process. For example, the load on the future structure is of primary importance, and attention is also focused on the appearance of the stairs. Industrial, public or private structures require compliance with the relevant requirements. At the same time, general rules and regulations that apply to each type of structure are important.
In public institutions, it is necessary to install a handrail on both sides. This requirement is relevant both in children's institutions and in other social facilities.
The parameters of the flight of stairs in this case are calculated taking into account the availability of free passage for two or more people.The minimum value is 1.3 meters. The established building codes and regulations allow you to make an accurate calculation using special formulas. This process is carried out at the design stage.
When developing a project, it is important to consider safety requirements. Much attention is paid to the material of the staircase structures. The surface of steps in public facilities should not be slippery, ideally smooth. The best option is a slightly rough surface, which will ensure safe movement. Each structural element must have the optimal dimensions, characteristics and dimensions. This approach will ensure comfortable operation, safety and ease of movement.
The SNiP requirements for stairs should not be considered as mandatory documents, despite the fact that they describe the dimensions, installation conditions, device and other important points. On the contrary, the requirements of GOST R 53254-2009, which regulate the manufacture and installation of both fire structures and fences arranged on roofs, must be strictly observed.
Official Edition
Basic provisions
Fire structures are carried out in marching and vertical design. For these types of stairs, SNiP were developed in the last century. For marching, the installation of fences is meant in any case, while vertical only starting from their height of 6 m.
The requirements for the norms of the device and the dimensions of the mid-flight fire escapes according to SNiP are as follows:
- Its stationary version must be made only of metal - the use of any other materials is prohibited. Portable can be made of aluminum;
- The steps must withstand the application of a vertical load of more than 180 kgf, the barrier structure - the application of a horizontal load of at least 54 kgf;
- The surface must be completely free of scale, cracks, burrs, rust;
- Strength tests are carried out every 5 years, and verification is carried out every year.
- Marches should be fenced with a metal structure of at least 1 m, and fences on the roof - 60 cm.
The requirements for the width of the steps of the stairs SNiP establish the following:
- Not less than 0.8 m for vertical ladders in the presence of a barrier, z not less than 0.6 m in its absence;
- For marching ones - at least 0.6 m.
Steel stairs
Back in 1981, SNiP II-23-81 was approved, the requirements of which apply to all structures made of steel. Despite its dilapidation, the document has not lost its relevance to this day.
When designing ladders SNiPom, two options for connecting their elements are established - by means of a bolted connection or by arc welding.
It is also possible to manufacture supporting parts not only from steel, but also from cast iron, since there are no shock effects during operation. When developing a project, it must be borne in mind that each element must be painted or galvanized.
In addition to the requirements for the structure itself, SNiP also gives methodological instructions regarding the calculation of strength, the use of steels of various grades, according to climatic regions.
General scheme
Reinforced concrete stairs
According to SNiP, stairs in public buildings, their dimensions are designed based on the following requirements:
- The minimum width is not less than 1.35 m. If more than 200 employees are allowed on a floor at the same time, then the width should not be less than 1.2. Near a separate workplace, it should not be already 0.7 m. For all other special cases, the march should not be already 0.7 m;
- The installation of marches is made with the greatest slope not steeper than 45 degrees, the slope of the march leading to a separate working platform, the permissible angle increases to 60 degrees;
- The width of the treads is set from 25 cm, the height of the steps is 22 cm.
Important!If up to 15 workers work in the workshop to which the staircase leads, the tread width can be reduced to 12 cm.
- The intermediate platform is arranged at least 1 meter wide;
- For evacuation stairs, SNiP provides for the prevention of overlapping paths with open doors;
- It is forbidden to place pipes on staircases transporting flammable liquids and gases.
- It is prohibited to locate cabinets and boxes on stairwells that are not related to the supply of various communications, as well as fire hydrants;
- The electric cable is not allowed to be placed open. The only exception is the wires directly intended for lighting the staircase;
- Heating radiators can only be placed in wall niches, while the layout of the staircase does not allow it to smoke.
Fencing
According to SNiP, stairs in residential buildings are also are regulated by the main dimensions and rules for placing fences:
- Railings on staircases of apartment buildings are mounted with a height of at least 1.2 m.
Important!The fences must be continuous, they must withstand the application of a horizontal load of more than 30 kgf for each linear measure.
- For individual residential buildings, the standards set the height of the railing from 0.9 m, while the remaining requirements for strength remain unchanged;
Important!In any case, if the size of the stairs exceeds 6 m, the railing is placed exactly 1 m.
- Roof fences of industrial buildings must have a minimum height of 0.6 m; if there is a parapet on the roof, the total height of the fence with a parapet is 0.6 m.
Wooden stairs
Two versions of documents contain the requirements of SNiP for wooden stairs:
- The erection of wooden structures is regulated by SNiP II-25-80;
- General requirements for the construction of residential buildings are covered in Sanitary Standards 2.08.01-89.
As such, the combination of the words "wooden staircase" is not present in the designations of these documents.
To wooden staircases, which are mostly arranged in individual houses, the following requirements are stipulated:
- Areas between floors should be lit with natural light;
- The march should be from 3 to 18 steps;
- Fences and handrails must be present;
- Installation of marches is made with the greatest slope not steeper than 40 degrees;
- The construction of wooden stairs is limited to the use of only softwood, deciduous varieties can only be used for steps, dowels and other elements that bear the main load.
Important!Larch, distinguished by its relative cheapness, does not lend itself to rotting even at high humidity and does not require a protective layer to be applied to it. But due to the excessive resinousness of the wood, it is not recommended for the construction of railings - it leaves splinters.
Wheelchair ramps
The main document regulating the construction of stairs and ramps is SNiP 35-01 2001. They are established for those whose ability to move without assistance is limited - mainly for the elderly and people with disabilities.
What dimensions need to be maintained
The main goals that are achieved by the introduction of this document:
- Providing unhindered access to buildings for people whose ability to move is limited;
- Increasing the level of safety of people when moving under standard conditions and during evacuation measures.
The following requirements are established:
- For people with reduced mobility, the width of ramps and stairs is set at least 1.35 m. If the width of such devices is more than 2.5, then handrails are installed in the middle;
- The maximum allowable slope of the ramp is no more than 8 degrees with the highest elevation up to 0.8 m;
- Treads are arranged no more than 30 cm, steps - no higher than 15 cm;
- On the same march, all steps must have the same geometric shape and size;
- The ribs of the steps are given a rounded shape, the outer edge of the tread is equipped with a 2 cm side.
Important!A ramp below 0.2 m can be built with a slope of up to 10 degrees.
- The ramp can be built up to 1 m wide if movement along it is mainly one-way;
- On both sides, the structures are equipped with double handrails - at a height of 0.7 and 0.9 m;
- The edges of the ramp are equipped with bumpers. Their size is up to 5 cm.