The maximum number of steps in a flight of stairs. How many steps should be in the stairs. Ergonomic calculation criteria

Such a parameter as the height of the stairs, SNiP and GOST is determined strictly. Not a single house will be accepted by the commission if it does not comply in its main elements with the Building Regulations and Rules, as well as other state standards. The only question is whether the stairs are among the main elements of the house.

What does SNiP say about stairs

The formation of norms for the construction of structures of vertical movement originates from the moment when multi-storey buildings began to appear. For the first time, the architect Blondel brought out the formula for the harmonious ratio of distances in the 17th century. It expressed the proportions of the vertical distances between the surfaces of adjacent steps (x), as well as the distance between their edges (y). The result is the formula: 2x + y \u003d 60-66 cm.

Stairs are the most actively exploited part of the building, so they are subject to special requirements for convenience and safety. Considering this requirement of the time, Blondel also deduced two formulas that are a consequence of the main one. The safety formula is x+y=46, the convenience formula is y-x=12.

A lot has changed since then, but the basics remain. The Building Codes and Rules were formed to ensure people's safety, but at the same time not at the expense of convenience.

All rules regarding stairs, according to SNiP, can be summarized as follows.

In a building with two or more floors, there must be one large span.
All ladders intended for permanent use must only be stationary. Transformable options can only be used as an auxiliary structure, for example, for access to the attic or basement.
The width of the span must necessarily fit in the range from 80 to 120 cm.
The number of steps in a march should be within the range from 3 to 18. In buildings where organizations with a constant flow of people are located, this interval is narrowed to 3-16. For ease of movement, it is recommended to build an odd number of steps. This placement allows a person to move in an optimal rhythm, starting and completing the ascent or descent from the same foot.
There is a standard for the angle of the stairs. It should fit in the range from 26 to 45 °.
The height of the step on any staircase must necessarily be in the range from 15 to 20 cm. Moreover, all of them must be the same within this staircase. The allowable difference is 0.5 cm.
The minimum width of one step is 25 cm. The exception applies only to transformable auxiliary staircase structures. They should not be already 20 cm.
The parameters of the stair ledge cannot be more than 3 cm.
Landing standards must correspond to the width of the steps. If two marches adjoin the site, then the site should not be less than 130 cm. The distance from the door to the beginning of the span should be at least 1 m. This indicator also depends on where the doors open. If the door swings outward, then this distance is determined by the width of the door.
SNiP also regulates the height of the fence. It depends on the height of the ceiling, since there should be a space of 190-200 cm between the ceiling and the railing.

SNiP on types of steps

The height of the steps is not arbitrary parameters, even within the framework of building codes. It depends on a number of project indicators. SNiP defines the following types of stair structures:

Ordinary steps are part of any stairs as the basis for the formation of these structures.
Runners are steps that are designed to ensure a smooth turn of the stairs. They differ significantly from ordinary ones and have different width along the entire length.
Steps-platforms are intermediate elements for stairs with a turn. However, in height fundamental differences from the base privates they do not have.
For open steps, the absence of a riser is characteristic. In this case, the flight of stairs takes on an openwork, soaring look. It looks nice, but it reduces the level of security.
In closed steps, a riser must be attached. Such a staircase looks monumental and creates a sense of security.
At hinged steps, a part of the tread protrudes above the riser. This form allows you to increase the width of the stairs and increase the comfort of movement.

The maximum and minimum heights of all these steps do not have significant differences, but still each of them has its own specifics.

Height options in different versions

The height of the steps is measured in the height of the riser, since it is this part that forms the distance between each element of the stairs.

This video will show you how to select comfortable height for a stair rung:

The state standard determines the height of the stairs in the range from 12 to 25 cm.

The optimal height of the main staircase element is formed in relation to the tread. Usually the proportions are set to 2:1.5 or 2:1. For auxiliary ladders, these proportions are reduced to 1.2:1 and 1:1. This means that the maximum height of a stair step is set at 25 cm. The tread is also measured by this value.

For street marches, an interval of 15-17 cm is usually determined. Internal stairs should save space, so a range of 17-22 cm is set.

Determining the height of steps during design is also provided by GOST and SNiP. The comfortable height for this project is calculated using the following methods:

based on the number of steps (the height of the march and right amount steps);
determination by step width;
calculation according to the safety formula;
comfort formula.

This video talks about step calculation:

AT different projects one or another method can be taken as a basis. It all depends on the purpose of the building, the wishes of the customer, the requirements for operation, regional features of comfort.

The calculation of the size of the steps of the stairs is carried out taking into account the type of construction. If it is rectilinear, use the same formulas. If it is rotary, it is important not to forget about the calculation of winders, the peculiarity of which is the difference in the dimensions of the outer and inner edges. There are many online calculators that allow you to quickly make calculations. But if you know how to correctly calculate the steps on the stairs, everyone can cope with this not so challenging task on one's own.

There are several ways to calculate the size of steps. Only after all dimensions are known, and the plan is ready, you can proceed directly to the construction of the stairs of the selected type.

On this page you will learn how to calculate the stairs with and without winders yourself.

Method for calculating the steps of a flight of stairs

To move up the stairs in the house without applying excessive effort, it is necessary that for each step a certain ratio be observed between the "distance" by which a person moves forward and the "distance" by which he descends or ascends. This ratio is called slope. Thus, the width of the tread and the height of the riser should correspond to the width of the average human step, and when the leg is raised by 300 mm, it averages about 600 mm. In construction, there is a rule according to which the width of the average step of a person is equal to the sum of twice the height of the riser (K) and the width of the tread (b):

2h + b = 600-650 mm.

For example, if the height of the riser is 185mm, then the width of the tread should be 270mm. So, according to the above formula for calculating the steps: 2 × 185 + 270 \u003d 640 mm.

With a riser height of 170 mm, the width of the tread will be 290 mm. This ratio is considered to be ideal. But in practice, when calculating the steps of a ladder, it is recommended to adhere to other parameters.

So, for example, in a house, the height of the riser usually does not exceed 170 mm, but sometimes it can vary from 120 to 200 mm or even more, and the width of the tread is from 280 to 300 mm (but it should not be less than 250 mm).

If the width of the tread is too large, then the step will go astray when climbing the stairs, and if the design is narrow, then difficulties may appear when descending.

Often the width of the tread is increased by about 20-30 mm (depending on the thickness of the riser), since stairs with deep risers are more convenient to use. But this is considered an extreme necessary measure when there is no other way to increase the width of the tread. At the same time, the width of the tread becomes larger, and the place intended for the ladder structure remains unchanged.

When calculating the steps of a straight staircase, multiplying optimal width tread on the number of risers, you can calculate the laying of the march, that is, the length of its horizontal projection. Prior to this, it is necessary to subtract 1 from the number of risers, since when the upper tread coincides with the level of the floor or staircase, the number of treads is reduced by one.

To calculate the length of the base of the stairs in this way, multiply the number of treads by their width. In addition, the length of the overall run and the length of the opening in the floor of the upper floor should be almost the same.

After the calculations, having determined the height of the stairs, you can calculate the number of steps and the length of the base of the staircase (general run). The height of the stairs directly depends on the height of the floor. How to calculate the number of steps? By dividing the resulting value by the height of the riser, you can find out the exact number of steps.

When initially choosing the height of the riser, it is important to remember that the quotient must be an integer, otherwise the steps will have different heights, and this is unacceptable. The fractional result must be rounded up for a more gentle design, or, conversely, to a smaller one, if it is assumed that the stairs will be steep. By dividing the total flight height by the number of steps and rounding the result, you can calculate the height of the riser.

How to calculate the size of the steps of the stairs by the height of the riser and the width of the tread

To select the parameters of the steps, you can use two rules, which are based on the height of the riser (h) and the width of the tread (5):

the first rule is a "convenience formula": b-h - 120 mm;
the second rule when calculating the steps of a ladder is called the "safety formula": b + h = 460 mm.

According to the above, in order to calculate the steps correctly, as required by the construction technology, it is best to choose a ratio between the width of the tread and the height of the riser, which is close to optimal. For example, stair structures with a tread width of 295 mm and a riser height of 150 mm will be considered convenient or

With a tread width of 230 mm and a riser height of 215 mm, since in both cases a total of 445 mm is obtained, which does not contradict the safety formula. Although, when calculating stair steps, a lot will depend on the location and shape of the stairs, the area of \u200b\u200bthe room and other conditions.

There are certain rigidity requirements load-bearing elements structures, as it is a structure, which during operation is greatly affected by dynamic loads.

In addition to the own weight of the stairs, there are also temporary loads, which in houses are approximately 300 kg / m2. So, the deflection should not be more than 1/400 of the span.

It should be borne in mind that both too narrow (less than 260 mm) and very wide (more than 320 mm) treads are inconvenient to use. With a narrow tread, there is a decrease in the area of \u200b\u200bsupport for the foot, during the ascent above the front edge of the step, the heel noticeably hangs, and when descending, the forefoot hangs down. Because of this, the leg may slip - there is a risk of injury. An excessively wide tread (the entire foot rests on it) requires an increase in step width. Because of this, you will need to make more effort while moving up the stairs.

Calculation of the steps of a straight staircase: a graphical method

The calculation of the steps of a flight of stairs can also be done graphically. It is ergonomic, as it uses natural human parameters. So, stride length horizontal surface is an average of 620 mm, and for easy raising of the leg, the ideal height is 310 mm. If a certain number of parts equal to 620 mm are set aside on the x-axis (horizontally), and the same number of parts equal to 310 mm are measured on the y-axis (vertically), then thanks to this, regardless of the slope, it will be possible to determine the dimensions of the steps for all staircase structures.

For this purpose, it is necessary to use graph paper (if it is not available, then ordinary paper in a small cell will do), on which you should draw the coordinate axes and measure the segments on the axes on a suitable scale, equal to the length pitch (on the x-axis) and lift height (on the y-axis). Then you need to connect the obtained points. Next, you need to draw a line for the slope of the stairs (in the corner). After that, dashed lines parallel to the axes should be drawn through the intersection points of the lines in the drawing. On the lines obtained, you need to draw a line - a "ladder". As a result, the resulting steps can be measured by adjusting for the scale.

A certain dependence will be visible between the parameters of the step (its width and height) and the slope of the stairs.

When calculating the parameters of the steps (rise height, width and shape), you should pay attention to the fact that these are the dimensions of the steps in the plan. In fact, they are editable. For example, you can increase the width of the tread by building a roller at the step (it is not recommended that the overhang of the tread be more than 50 mm). You can also make a beveled riser (but not more than 50 mm) or completely abandon it. Thus, it is always possible to make the tread wider, and the ladder easier to use when climbing. But the safety of the descent does not increase, since the calculated dimensions of the steps remain unchanged.

The size of the total run is calculated by the number of risers, the size of the treads and the way the ladder is attached at the top. For the manufacture of a simple single-flight staircase, it is advisable to choose several options. For example: 13/206, 14/192, 15/179, 16/168. The first number here indicates the number of risers, and the second - their height.

Convenience and safety in the use of a ladder structure largely depends on the angle of its rise, that is, on the relative magnitude of the rise of the flight of stairs.

Despite the fact that the angle of rise of the flight can vary from 20 to 50 °, stairs will be ideal, the relative value of the rise of the flight of stairs is from 23 to 38 °. Ladder structures with a steepness of up to 38 ° can be considered gentle, and steep - with a slope of 38-45 °. If the slope is less than 23 °, then it is recommended to put a ramp instead of a ladder. If the slope exceeds 45 °, then it is desirable to change the type of stairs, because of the steepness, it can be attached or folding. For screw structures, an elevation angle of 25-35 ° is considered ideal.

The main factors in determining the steepness of the stairs are the age of those who will move along it (since a slope of more than 38 ° will be inconvenient for the elderly), as well as the size of the place intended for the structure.

There is a certain relationship between the height of the floor, the height of the steps and their number, depending on the degree of steepness of the staircase structure.

When choosing the steepness of a flight of stairs, it should be borne in mind that the distance from the upper plane of each step to the ceiling (clearance height), according to building codes, should not be less than 1900-2000mm. The greater the clearance, the more convenient the ladder, especially for tall people. The same applies to stairwells. A device with a sufficient clearance will eliminate the risk of hitting your head on the ceiling, and you can also forget about problems with moving large objects.

The final section of the article is devoted to how to calculate the steps turning stairs.

How to calculate winder steps: a method for calculating a turning staircase

Prior to this, it was about the steps of rectilinear stair structures. To save space, instead of intermediate landings between straight flights, it is recommended to lay winder steps. Their outer and inner edges have differences in width. Such stairs are distinguished by the fact that the change in the direction of movement along them occurs smoothly due to the gradual transition from straight steps to running ones. How do you need to calculate the size of steps on a turntable?

When calculating a turntable with winder steps, it must be borne in mind that the smallest width of the tread at the narrow end of the step must be at least 100 mm, and the overhang over the underlying step can be no more than 50 mm. Winder steps have a peculiar wedge-shaped shape, the creation of which requires special skills. Calculations can be made in several ways.

The most common method is proportional division. Let's consider it on the example of designing a half-turn single-flight staircase with middle winder steps.

Before calculating the winder steps, you must first divide the middle line of the march into equal parts, while there should be one step in the middle of the semicircle.

The width of its tread at the narrowest point is pre-set, but it must be more than 100 mm. If there are four points for the central step, draw lines for it longitudinal edges, then continue them until they intersect with the axis of symmetry. Obtained as a result of these actions when calculating turning steps point - the first point of the proportional division segment - can be denoted by the letter A.

To find the second point of proportional division, it is necessary to connect the contours of the straight steps, which are adjacent to the winders. This is how the point of intersection with the axis of symmetry is determined. When calculating a staircase with winder steps, it can be denoted by the letter B. Then the straight line AB should be divided into segments in the proportion 1: 2: 3: 4: 5: 6, i.e. their number should be equal to the number winder steps on both sides of the axis of symmetry. As a result, you need to connect the division points of the axis of symmetry with the division points of the midline of the march.

When "removing" dimensions from the drawing, you should carefully check the dimensional chain of all steps by the addition method. As a result, the sum of the dimensions "taken" from one side of the steps should not be more or less than the actual size of the stairs in this area.

In the design of rooms and buildings, stairs play a huge role both visually and functionally, therefore, to such structures, especially designed for buildings general purpose, there are quite serious requirements for the development of the project. Due to the fact that in such places an enormous load is placed on the staircase structure ( trade pavilions, exhibition halls, residential buildings, buildings of higher educational institutions, hospitals, restaurants, etc.), the requirements for stairs and landings must be calculated taking into account the expected maximum loads. Their device, the materials that are used for their environment (outside or inside public buildings), various other parameters for each type of buildings and stairs must be able to distinguish.

Standard requirements for the construction of stairs in public buildings

Stairs in buildings are always a risk area due to the structure itself, therefore, when developing and designing it, absolutely all factors should be taken into account, even minor ones, for example, if children will use the stairs. Here you should consider both stairwells and the degree of illumination from natural and artificial sources. The task of the designer is to identify the shape, slope, size of steps as close as possible to the comfort and idea of the customer, taking into account the material from which it is planned to make the staircase, and, calculating the design of the staircase in accordance with its purpose, adhere to SNiP and GOSTs for the selected type.

If in the construction of buildings according to personal projects for private houses, small deviations from the norms are allowed due to a relatively small load, then for the design and construction of stairs in public buildings compliance with standards, GOSTs and SNiP are mandatory, otherwise such a structure is simply unacceptable for use.

Classification of flights of stairs and their tasks

Let us first consider the classification of stairs according to their purpose and tasks that various stairs perform.

The primary task is to organize convenient access to the premises with the help of equipment with flights of stairs. multi-storey buildings. They usually have elevators, but stairs are needed in case the elevator is busy or out of order. Stairs should provide the main movement between floors, and its width and height should be built according to the parameters that will allow movement. a large number people, bulky furniture and other cargo. This task in the building should be solved by the main staircase.

The existing other types of stairs solve many equally important tasks, so let's take a closer look at them.

Secondary stairs in general premises

An auxiliary staircase is a structure designed for technical, auxiliary rooms. This includes pantries, attics, basements, etc.

The service ladder is a structure intended only for employees (in hospitals, maternity hospitals, trading floors, buildings of culture and city services, buildings for production work, workshops in a factory, sports stadiums, etc.). This staff ladder has small size and allows the movement of a small number of people.

An emergency ladder (spare, evacuation) is a structural element that can be located both inside the building and outside. When natural disaster or fire, such a staircase should ensure the evacuation of people if the main staircase is inaccessible for any reason.

A fire escape is a structure leading to the roof of a building, it is intended for use by firefighters, sometimes it is an attached tool. In the event that an inclined staircase constructively interferes, it is possible to make it vertical in compliance with all the rules for access and security, that is, maintaining its direct purpose.

Requirements for the arrangement of stairs in public buildings

Designers developing appearance taking into account the practicality of the structural elements inside the premises, as well as the builders of two-level apartments, multi-level floors in offices, must take into account the placement of stairs, their type and type even before starting work, in order to correctly calculate all the loads and complete the project taking into account all the details. Here you need to calculate in advance the ways of attaching stairs to walls or other load-bearing structures, make the correct dimensions of the openings and determine their location in the ceilings between floors.
This also includes the basic requirements for regulatory documents regarding the slope, march width parameters, connecting platforms, and the number of steps in one march.

All kinds of requirements for stairs and platforms include standards for calculating loads that allow the operation of the stairs, and means that increase the safety and comfort of using the stairs: handrails, handrails for children, enough high fences and smooth railings, narrow spaces between filler slats in the stair railing.

How it's done

Determining the planned type of stairs is easy. What the future building is intended for, and where the staircase should be located, the sketch will tell. When it is still at the design stage, attention should be paid to the following details: what intensity of movement of the mass of people will pass on the stairs, what is the planned difference in levels between which it will be installed; what size, shape it is supposed to have space for its placement, what technology will be used to build it, whether and where the supports will be located; what are the expected maximum loads during operation, and, of course, its external presentability. The last nuance depends in general on the purpose of the designed staircase, but the most simple options can be built with taste so that the ensemble of the building and all its elements as a whole harmonize and meet aesthetic requirements.
When the type of stairs is selected, you need to deal with its parameters. It is necessary to calculate the number of marches, their dimensions of length and width, the dimensions of interfloor platforms, their shape, and number.

Number of steps and parameters according to SNiP

SNiP require that in residential buildings the number of lifts inside one flight of stairs be from 3 to 18, as for the SNiP rules for public buildings and structures, they limit the number of lifts inside one flight of stairs from 3 to 16. Flights of stairs in public buildings with elements spiral staircases, winder steps, others decorative elements if the use of this flight of stairs implies its evacuation purpose.
According to these rules, the size of the steps must also be taken into account. The standards say that the width should not exceed 0.25 m, and the height - 0.22 m. It is unacceptable to make the dimensions different, otherwise the injury risk of the stairs increases.

Calculation of the slope of the flight of stairs according to the requirements of SNiP

If the staircase is one-story building can be made with a slope of 1:1.5, then in buildings above two floors (inclusive) the slope of the march should be 1:1.75. Evacuation and fire escapes allow a larger angle, the maximum slope of such stairs is 1:1.25.
The slope values vary depending on the width and height of the steps on the stairs. The wider the steps, the less angle slope, that is, the rise is more gentle, and the narrower the steps, the steeper the slope of the stairs.

On average, the slope angle for auxiliary stairs (fire, evacuation, fire) is allowed up to 45 degrees, stairs in residential premises can be tilted from 30 to 45 degrees, stairs in in public places- from 20 to 30 degrees, outdoor - from 5 to 20 degrees.

Entrances for people with reduced mobility

According to the regulations, many shops, shopping malls, pharmacies should be equipped with ramps. The slope angle of the ramp should not exceed 5 degrees.
This moment is regulated by SNiP 35-01-2001, which means ensuring accessibility to public buildings for the elderly, for people with disabilities moving in a wheelchair and with a cane, for people with limited mobility. The dimensions of the ramp must ensure the movement and, in particular, the evacuation of people in a safe way, so the design of the ramps must meet the following standards:

Width - 1.35 m and wider (if the ramp is wide, more than 2.5 meters, it is necessary to install dividing handrails, if it is one-sided, a width of 1 m is acceptable),
The steps of the flight of stairs are strictly the same size,
The height of the steps is a maximum of 15 centimeters and the width of the tread is not less than 30 cm,
Rounded edges of steps, the presence of a side along the edge of at least 2 cm in height.

Only after the main calculations approved in the sketch, you can proceed to the choice of style and material for the execution of the main frame. Then selected auxiliary elements. This is the material (glass, wood, metal), and color, and accessories for decoration, etc. Then the aesthetic solution will correspond to structures that meet the requirements of convenience, safety, beauty, durability and economic feasibility.

Requirements for stairs of various types

When developing a project for an architectural object, you should design the stairs in the house at the same time as the full project of the building, for a complete understanding of the emergency exit zones.
By appointment different types stairs must comply with special building codes and regulations (SNiP). They are established by executive authorities that regulate urban planning activities. As a rule, the main articles SNiP 4-14-84, SNiP 21-01-97, SNiP 31-02-2001, GOST 23120-78, GOST 25772-83 are used to regulate structural elements.

It should be noted that adherence to GOSTs is a strict requirement for the structures of public buildings, and SNiP are only recommendations that should be followed.

However, the importance of these rules is still obvious. Work on calculations in accordance with SNiP and competent design of stairs is guaranteed to create conditions in the room for maximum possible security people's lives.

What are the general requirements for any kind of stairs in public buildings

The design should be as safe and convenient as possible, since the movement of people in public places is very intense. The least traumatic is considered a direct mid-flight design. And not allowed to use screw structures, in particular with winders, otherwise the safety requirements will be violated.
The reliability of the design should concern not only the ability to withstand heavy loads (to achieve strength, only special durable materials: concrete, reinforced concrete), but also provide reliable fences.
Stair elements such as railings and steps are one of the main reliability criteria if they are made in accordance with SNiP.

Stair railing

The railings are railings, and the maximum side load on them is at least 100 kg. The side railings must withstand such a weight, and the racks (balusters) must be located at a distance of 12-15 cm (and they cannot be reduced). How to fill them out is also specified in the GOST standards. It is possible to make the distance between the racks filled with metal, glass, plastic screen in public places (general buildings). For buildings where children are located (schools, kindergartens), you can only use vertical elements, that is, without setting the screen. The safety measure in this case is the good visibility of this option.

The staircase is equipped with handrails on both sides, the height of each handrail is 0.85 m. If we are talking about sports stands, the height of the handrail increases to 1 m. required, it is installed along the wall. On stairs in kindergartens, theaters, buildings elementary school additional handrails are installed, with narrow railings at a height of 0.6-0.65 m. If the flight of stairs is wide (if its width is over 2.5 m), a central railing is installed in the center.

Steps and achievement of safety according to the stipulated rules of cases

As for the steps, they must be made of anti-slip material, or at least partially covered with it. These can be rubberized stickers, non-slip strips, grooves in the edges of steps lined with polished stone, or covering them with an anti-slip carpet with a rubber base that prevents the rug from sliding on the surface of the steps. Such coatings serve not only for stone stairs, but also for metal, glass, wooden stairs, and in the latter case, they extend the life of the stairs.

If the stairs are installed in a house or a general-purpose room where there are children, then it is recommended to make the steps deaf, with a riser. If a room for a large number of children, such as a theater or camp with stairs, where the height of the steps is on average 15 cm, children in mobile movement and inaccurate falls can be seriously injured if a limb gets caught between the steps.

Lighting is a significant factor in building stairs

Good staircase lighting should especially touch the top and bottom steps. It is also necessary to consider easy access to switches. If the staircase is equipped in such a way that the contrast of light and shadow is sharp enough on the steps, then the edge of the step will be clearly visible. And this means that the possibility of injury on the stairs will noticeably decrease, because the slipping of the foot from the edge of the step will be excluded. According to statistics, most injuries occur precisely because of poor visibility or merging shadows on the stairs.
If lighting is taken seriously, the automatic on-off light system has proved to be very convenient, lasting several minutes and reacting with a motion sensor to any movement up the stairs or entering the sensor's visibility zone.
Windows, past which the level of the flight of stairs passes, if it is adjacent to the wall where the window is located, must be fenced in order to prevent falling out of the stairs into the window.

Types of flights of stairs allowed by SNiP

SNiP requires that in public institutions, multi-storey apartment buildings residents used only a two-flight staircase. This option classically looks like this: two flights of stairs are constructed between two floors, interconnected by an interfloor platform. Options for making housing non-standard, but remaining within the framework of these rules, can be as follows:

U-shaped spans connected by a rectangular interfloor platform,
U-shaped spans connected by a trapezoidal landing (i.e. using winder steps to smooth and round the corner),
L-shaped marches connected by a square interfloor platform,
straight marches, following one after another in succession, but located in a straight line, connected small playground etc.

Dimensions of flights of stairs according to SNiP

SNiP requires the design to comply correct sizes. For example, it is recommended to make a staircase the same width as landing. There are restrictions on minimum size. The staircase cannot be narrower than 1.05 m. If we talk about corridor stairs, structures of at least 1.2 m are acceptable. If we are talking about a basement structure, you can limit yourself to 0.9 m or more. If it is a fire escape, leave at least 0.7 m.

Emergency, fire and evacuation stairs and requirements for their equipment

Evacuation and fire escapes are prohibited if their design contains helical, curved structures, winder steps, different sizes steps in one area.
These standards strictly meet the safety requirements for evacuation. As for fire safety, such a ladder must be made of fire-resistant materials. As a rule, this reinforced concrete structures or metal stairs. All the requirements specified earlier in the form of parameters of steps, platforms, slope and illumination apply to fire escapes. Such stairs should lead people outside, to the street or to separate room protected by a door from fire and other emergency effects outside the emergency building.

Requirements for the equipment of emergency stairs

Geographic location and climate zone, where the building is built, affects the choice of the type of emergency stairs.
In regions with a cold climate, such stairs are also allowed to be installed outside, but this cannot be done above the level of the second floor. An indispensable condition here is also that the building is not among the children's institutions.
External fire escapes mounted outside must ensure that the steps are not covered with snow, ice and frost, so that they can not retain dirt, sand, and precipitation on the steps. This is very important requirement, as panicking people during the evacuation are in a hurry and behave carelessly.

Emergency ladders mounted outside buildings must be made of very wear-resistant and anti-corrosion material, for example, of stainless steel or metal coated with an anti-corrosion compound.

Fire escapes located inside buildings can be made of metal with a special refractory coating or concrete. It is strictly forbidden to use materials that can release toxic substances during combustion to install ladders. Each element of such stairs (handrails, balusters, steps) must also meet the requirements of the rules.

Finally

It should be remembered that flights of stairs installed in public buildings should not include elements of spiral stairs, winders, decorative elements in the form of forging or other protruding parts, if this staircase is also planned to be used as an evacuation staircase.

Having fulfilled all the requirements of SNiP and GOSTs for ensuring safety inside or outside it, you can confidently begin the construction of a building with designed stairs without fear that the building will not pass commissioning or will ever cause disasters.

Having confidence that your staircase does not violate the requirements, pay attention to the design part, because this structural element serves as one of the expressive interior items inside the room and an architectural component outside - and at least the same ones will significantly improve the appearance.

What are the options for arranging stairs at home? Let's discuss in the comments to the article, practical experience always valuable and will be of interest to others.

Standards, norms and rules currently exist in order to ensure the convenience and safety of people's lives. To a large extent, this principle applies to the construction of various buildings and structures that people use either for housing or for work.

Stairs are essential constructive element buildings, and the peculiarity of their use requires especially careful development.

Therefore, in the design process, civil engineers consider the following factors:

march width;
the width of the steps;
the angle at which the steps are inclined;
step height.

The adopted standards are set out in normative documents, which are mandatory for construction work for the construction of stairs. So, GOST on steps for reinforced concrete stairs is in the document 8717.1-84 (there are descriptions of the rules related to the design and dimensions) and in 8717.0-84 , where the technical conditions for the development and manufacture of stairs are collected.

GOST on stair steps, made of metal structures, is in document 8717.0-84. Except state standards there are approved "Building Norms and Rules", which lists the calculation methods and key factors, which must be taken into account in independent calculation and design.

Builders have accumulated sufficient experience, which allows them to successfully design and build solid and beautiful stairs. The main rule that allows you to build a staircase that will be comfortable and safe to move on is the relationship between the distance of movement forward and the height of the ascent / descent.

This ratio is calculated using two parameters:

distance in centimeters between the surfaces of adjacent steps (x);
distance in centimeters between the edges of adjacent steps (y).

In the 17th century, the French engineer Blondel developed a formula that relates these two quantities:

2x+y=60.

From this formula (it is called "ideal staircase formula") the following two were derived:

safe ladder formula - x+y=45;

and formula comfortable stairs y-x=12.

Today's building science has advanced further and modern GOST takes into account much more different parameters for the dimensions of the stairs. That's why various norms and there are more rules. Modern norms much more attention is paid to the safe operation of buildings and stairs as well.

Therefore, the mentioned "Construction Codes and Rules" regulate the design and construction of reinforced concrete and any other stairs in sufficient detail, and also put forward clear requirements that must be observed. Violation of these rules and requirements may result in administrative liability.

Compliance with the following design rules will help to avoid this:

A building or structure with more than two floors must have one large flight of stairs;
Mobile ladders can only be used for attic or basement spaces;
A flight of stairs for the passage of one person must have a width of at least 0.8 - 1.2 m (the width must remain constant along the entire length of the flight);
One march span can have an odd number of steps (from 3 to 17);
The angle of elevation of the flight of stairs should be in the range of 26 - 45 degrees;

Reinforced concrete stairs– a beautiful and practical architectural element

GOST for the height of the stairs prescribes to adhere to dimensions in the range of 150 - 200 mm;
The height of the steps within one flight of stairs should not differ by more than 5 mm;
The width of the step in the building must be at least 250 mm (200 mm is allowed for basements and attics);
The distance of the step protrusion should be no more than 30 mm;
The distance from the door to the step must be at least 1 m (if the door opens outward - not less than the width of the door leaf);
The landing, to which two spans adjoin, must have at least 1.3 m;
The railing of the stairs must have a height of at least 900 mm (the distance between the balusters in it must not be less than 100-150 mm).

Design rules

When developing a project and determining the type of stairs, many factors are taken into account, the main of which are the requirements put forward by the customer.

The following conditions are taken into account:

the nature of the movement of people on the stairs;
planned loads on the structure;
manufacturing technologies;
design solutions;
the presence of space for the structure and additional supports.

When designing, the fact that the staircase is a high-risk area must be taken into account. Therefore, safety issues during the construction and operation of stairs are important. One of the main requirements in this regard is to comply with GOST for the height of the stairs.

The designer must choose the appropriate height according to the standards specified in the documentation. As practice shows, most injuries on the stairs are associated precisely with non-compliance with these standards.

The design of handrails for stairs and railings must take into account the design load with a margin. The instructions indicate that handrails and railings can withstand at least 100 kg, which allows an adult to lean on most of his body weight.

One of the important design parameters is the distance between the ceiling and the steps, which should be at least 1.95-2.00 m. The critical height of this design also applies to the stairwell.

Advice! When designing ladder structures, it is necessary to take into account the material from which they are made. It is best when the design provides for additional coverage on smooth and slippery surfaces. For example, for home stairs it could be carpet covering which will not only provide safe operation, but will also perform soundproofing and aesthetic functions.

Ergonomic calculation criteria

When calculating the width of the tread, the need for an adult to be able to lean on the step should be taken into account. full foot. That is, the width of the tread should be within 20 - 32 cm.

It is optimally considered that the riser should be about 15 cm, and the width of the tread should be twice as large - 30 cm. If the width of the tread is greater, then the person walking up the stairs will lose his stride, and a significant decrease in the width of the tread will make the descent much more difficult.

When designing winder steps, it is necessary to take into account minimum width steps from the narrow end of 10 cm, and the overhang distance of the tread should be less 50 mm.

Norms allow stairs to be installed at angles of 26-45 degrees, but angles greater than 37 degrees are considered “uncomfortable”. It is advisable to replace stairs with an inclination angle of less than 23 degrees with ramps (smooth inclined platforms). Stairs with an angle of inclination greater than 45 degrees must be either attached or folding. For spiral staircases, the optimal angle of inclination is 25-35 degrees.

Measurement procedure and design tools

If the staircase is built with finishing work, then for measurements you will need the following tools:

roulette;
level;
long straight rail;
an extra pair of hands.

The order of measurements is carried out in the following sequence:

The perpendicularity of the walls is checked by a square;
The height of the ceiling and the thickness of the ceiling are measured;
A plan is being made on graph paper with a section of the room (on the plan it is necessary to take into account the measurement data not only of the floor and openings, but also of doors, windows, etc.);

When making a sketch, the dimensions of standard products should be taken into account (this will avoid additional costs for individual production constructive elements).

Advice! You can save on the construction of stairs using exactly standard elements in assembled form. In Russia, various manufacturers of these elements adhere to certain standards, therefore, when developing, it is necessary to familiarize yourself with the standard dimensions.

Evacuation through the stairwells

The main goal of developing and complying with standards, norms and rules for stair structures is related to the provision of norms fire safety, which are aimed at ensuring, if necessary, the competent and quick evacuation of people who are in the building. With regard to evacuation and the role of stairs, the following should be noted.

In no case should the evacuation ladder be less than the width of the doorway. The slope must be observed in a ratio of 1: 1, and the height and width of the steps according to GOST is determined at 220 and 250 mm, respectively.

It is not allowed to place gas pipelines, built-in cabinets (except for electrical and switching cabinets) on stairwells, install equipment that will protrude above the steps of the stairs for a distance greater than 220 cm. Elevator cabins (but no more than two) can be placed on the stairwell.

findings

Designing stairs with your own hands is quite a feasible task, subject to certain rules, standards and norms. If during this work we link together constructive, aesthetic and architectural solutions for the entire building, then the result will be good, and the staircase will turn out to be durable, practical, aesthetic, and its price will be acceptable.

In the presented video in this article you will find Additional information on this topic (learn also about the advantages of dielectric stairs).

Number of steps in flight of stairs- the value on which comfort depends for many years, and therefore it is worth considering this issue as thoughtfully as possible. Many factors must be taken into account. Let's take a look at the most basic ones.

What determines the number of steps

We are not talking about ready-made building staircases, they are made standard, all their dimensions are made according to SNiP, it is for these dimensions that the height of the floors and the dimensions of the staircases are calculated. Problems with staircase calculations begin if the staircase is manufactured according to individual project and already there are many restrictions in dimensions.

It is logical that the number of steps directly depends on the length and height of the stairs. But there are some limitations here. The number of steps in one march should not be less than 3 and more than 16. There is a rationale for this. If the height of the rise is such that one or two steps are enough, then the manufacture of the stairs is technologically unreasonable and it is quite enough to confine ourselves to a ramp - a straight inclined rise. If there are too many of them, then climbing such stairs is extremely tiring, especially for older people. When installing a long staircase, instead of one long march, several short ones are made, between which there should be rest areas.

The angle of inclination of the stairs varies depending on the design features, design and size of the room, but it should be in the range of 20-50 degrees. When designing a staircase, it is necessary to strive to ensure that it turns out to be as steep as possible. Optimal angle building codes consider 20 ... 30 degrees. If the slope is steeper, then the ascent becomes more difficult, and the descent becomes more dangerous. According to geometric rules, the leg lying opposite an angle of 30 degrees is equal to half the hypotenuse. And this means that the length of the flight of stairs is approximately twice the height of its rise.

Optimum step height

If the steps are high, then no matter how elegant the staircase is, it will be inconvenient and difficult to use it. And both during the ascent and during the descent. Similarly, with low steps, you will not have to climb, but mince, which is also very tiring. So building codes the recommended height is stipulated - from 17 to 20 one centimeter for residential premises. Deviations in one direction or another are allowed, but not more than 2 centimeters. You will have to use a calculator and accurately calculate the height of the steps with a different number of them, thus choosing the optimal number of steps.

The rise of all steps in the span must be exactly the same.

This is very important condition and must be strictly adhered to. Studies have shown that if only one step differs in height from the rest by only 5 mm, then this leads to a sharp increase in the number of injuries. Therefore, you should take a very responsible approach to marking the steps in the march, avoiding any discrepancies in size.

Video about the method of calculating the number of steps and the angle of the flight of stairs:

According to the formula, derived by long experience, when designing stairs, they are guided by a rather simple figure - the sum of the step height and its width should be equal to 450 ± 20 mm. If calculations result in strides that are too high or, at normal height, narrow, the entire design should be carefully reviewed. It will have to be redesigned. Do not under any circumstances endanger the safety of yourself and your loved ones. By hurrying now, you risk getting an inconvenient and dangerous structure that you have to use. long years. A properly designed staircase will become a real decoration of your home.

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