Precast reinforced concrete stairs are fireproof structures and are mounted in a special room - the staircase. In the presence of crane equipment for building a house such stairs allow you to work efficiently and quickly. Particularly suitable for high-speed construction of prefabricated stairs from large reinforced concrete elements.

In the practice of building residential buildings, typical reinforced concrete stairs with a slope of marches of 1: 2 are most common. In addition to them, steeper ladders with a slope of 1: 1.75 and 1: 1.5 are widely used in cottages, which occupy much smaller areas.

Ladder marches (GOST 9818–85 ×) are made of several types: LM - flat without frieze steps; LMF - ribbed with frieze steps; LMP - ribbed with two semi-platforms or with one upper semi-platform (fig. 18–20). Flat and ribbed staircases differ from each other in that in some steps they are made on a reinforced flat slab, in others on two reinforced concrete beams - kosoura.

Both those and other flights of stairs are solid reinforced concrete structures, steps in which are molded together with a slab or skewers. Ladder marches of the LMP type - more integrated reinforced concrete elements, here in one design are combined: steps, kosouri and one or two ladder semi-platforms.

Fig. 18. Prefabricated (flat) reinforced concrete stairs used in buildings with transverse load-bearing walls (platforms with ends or cantilever projections lean on the load-bearing walls of the staircase)

For each type march, concrete products are used to produce staircases: 1LP - flat for LM-type marches; 2LP - ribbed for marches of type LM; LPF - ribbed for marches of type LMF; BOB - ribbed finite semi-platforms for LMP-type marches.

The flight of stairs, staircases and steps are made in two versions: right and left - for stairs with a rise, respectively, counterclockwise and clockwise.

All reinforced concrete stairs should be designed and applied to the floor plan of the house prior to construction. This is not the kind of stairs, work on which can be attributed "for later." Such ladders are built according to the working drawings of the project, where all elevations, horizontal dimensions and mounting clearances are indicated.

Installation of stairs is made simultaneously with the construction of walls. The installation employs three people who, as the walls grow, after measuring the horizontal and vertical dimensions, lay the landings and marches with a crane.

Prior to the installation of landings and marches with a tape measure, check their dimensions and make a wooden template that copies the profile of the supporting part of the flight of stairs. Then on the walls of the staircase mark the site installation site, put a layer of mortar and set the site. Check the position of the installed staircase vertically and in plan.

If necessary, correct the position of the site with assembly scrap or raise it with a crane and install it again, achieving the design position. The mark of the top of the pads must strictly comply with the design, otherwise the flight of stairs will be crooked or fall between the pads. For alignment of sites in height and in plan use a wooden template (Fig. 21).

The flight of stairs is served by a crane using a four-legged sling with two short branches, which, when being lifted, give the elements a little more than the project slope. Stair flights without mounting loops are mounted with a forks.

Before installing the march installers arrange a bed of cement-sand mortar on the supporting sites of landings, throwing and leveling it with trowels. When installing staircases, one installer is located on the lower platform, the other - on the top or on the scaffolding next to the staircase.

He first takes the flight of stairs and directs him to the stairwell. At a height of 30–40 cm from the landing site of the march, both installers press it against the wall, give the crane driver a signal, and install the lower end of the march first, then the upper one. Inaccuracies of the installation are corrected by crowbars, after which the sling is unhooked, the joints between the march and the sites are grinded with cement and sand, and inventory fences are installed.

If the landing of the march on the supporting platform will go in the reverse order (first up, then down), then the march may break from the upper platform. With such a landing march can also occur jamming it between the pads.

Typical stair designs allow to arrange ladders for most standard floor heights (2.7; 2.8; 3; and 3.3 m). In staircases with transverse load-bearing walls, staircases of the type 1LP, 2LP and PSL are used, which, with their ends or supporting ribs (consoles), enter the wall masonry.

For 1LP platforms without a supporting rib, another installation option can be used, in which the floor and the interfloor platforms are supported on steel "chairs" (cantilever brackets) rigidly anchored into the walls of the staircase. In this case, all the walls of the staircase can be carriers. Ladder marches of the LMP type are used in buildings with longitudinal load-bearing walls, these marches as well as half-platforms of the BOB - cantilever structures.

In low-rise cottage construction, a reinforced concrete staircase can be built in an open staircase (in a niche). With a certain planning of the building, to save space, the floor staircases are not installed, and climbing the stairs and descending from it should be arranged directly from the floor slabs.

In this case, the flight of stairs should be supported on the supporting lintel or reinforced concrete beam (girder, girder). It is impossible to rest the stairs on the floor slab (fig. 22). The height of the jumper (or beam) is chosen so that the height of the final steps is equal to the ordinary steps of the march, that is, take into account the full thickness of the floor covering arranged on the floor slabs.

Usually the flight of stairs arrives at the construction site with smooth steps made of heavy concrete. To give the staircase an elegant look (Fig. 23), the steps can be lined with marble or granite treads, supplied with the stairs.

In a corresponding way (treads or other materials of the same thickness), the staircases are also finished. The thickness of the treads must be taken into account when designing the height of the floor, as they, laid on the steps and platforms, will raise the level of the "clean" floor.

If the entrance to the building is organized through the staircase under the first intermediate platform, then with a floor height of 2.8–3.0 m, a basement march of 3–6 steps leading to the first floor platform is necessary. In this case, the construction of stacked reinforced concrete steps, laid on steel kosouram or brick walls.

When designing stairs, their manufacture and installation, it is necessary to strictly observe the paragraphs of GOST standards and adhere to the requirements of SNiP (construction norms and rules). The second type of regulatory documents is recommended for implementation, but is not strictly mandatory. They are designed to prevent gross errors in the design of wooden, interfloor concrete, spiral, flight and fire stairs in constructed residential and public buildings. Relying on the norms of SNiP, they build safe (during descent and ascent) for people, convenient in operation, not provoking dangerous situations and objects corresponding to the rules of residents evacuation.

There are basic design requirements and separate building codes for each type of staircase located inside, outside residential and public buildings. At the stage of drawing up a project, the general rules apply at home They state that:

• In buildings whose height exceeds 2 floors, the main stairs must have a common span;
• Transformable species as the main use in multi-storey buildings are not allowed. Their purpose is safe access to the basement and attic rooms;
• At the main staircase, the width of the march depends on its throughput:
• The passage of one person - the width is strictly 0.8 meters;
• The passage is simultaneously 2 people - the width is strictly from 1.0 meter;
• Regardless of the capacity - the staircase must have a width equal to (no less, it is possible more) the width of the escape route;

• Constructions connecting more than 2 floors and pivoting stairs are designed, according to GOST standards, with a width of march from 1.0 m to provide a safe passage for several people at once;
• The dimensions of the marches in the presence of lifts for persons with disabilities are from 1.5 m;
• The construction of two-and multi-march ladders should take into account the same width of the march along the entire height of the object;
• If the project marches are placed in the opposite direction to each other, then provide for a mandatory 50 mm or more gap between them;
• The number of steps should be odd - from 3 to 18. The SNiP stipulates that it is more comfortable for people to start and finish the course with one foot;
• The slope of various types of stairs is calculated as follows:
• The objects inside the house and the main interfloor ones are the rise at an angle of 45 0 (slope 1: 1 not more) and 26 0 40 ’(slope 1: 2 not less);
• The upper limit of the slope is a rise at an angle of 50 0 (slope 1: 0.85);
• The lower limit of the slope - the rise at an angle of 20 0 (slope 1: 2.75);
• Ladders - rise with a slope greater than 1: 0.85;
• Ramps - slope less than 5 0.

Some requirements of GOST standards and SNiP overlap. When drafting projects, the purpose of the construction is important. In residential and office buildings, the requirements of comfort and safety of people play an essential role, therefore, compliance with SNiP is recommended.

General requirements for staircase elements

Regulatory documents describe the parameters of the staircase elements - steps, fences, lighting. Based on the SNiP, design a convenient object for moving people up and down the marches. Therefore, in the preparation of the project of internal stairs for high-rise buildings with high traffic, their compliance is highly desirable. In the presence of GOST requirements for the construction project regulatory documents are compared. In view of the fact that the staircase elements must be comfortable in operation and safe, their dimensions are made as follows:

• Degrees.

The height within one flight of stairs is not less than 12 cm and not more than 20 cm. At the same time, the difference in the dimensions of the steps should not exceed 5 mm, otherwise an uneven slope will be observed, which is unsafe during descent. The width depends on the purpose of the building under construction. If there is a design of stairs for a residential high-rise building, then the width of the steps should be from 25 cm (we are talking about the main interfloor objects). In public buildings, this parameter is reduced to 20 cm. If the steps have a width of 0.26 meters, then its protrusion should be no more than 30 mm (less possible).

• Wedge-shaped steps.

Treads from 10 cm on the inner border of the useful width of wedge-shaped (zabezhnyh) degrees. The size of the tread increases to 26 cm (at least) for marching ladders.

• Staircases.

Sizes are calculated according to the useful width of the adjacent marches. They should be no less. The platform should have a length equal to 2 sizes of an average step of an adult person. Physical quantity - 1.31-1.42 meters. If the landing is located in front of the main entrance, then its length must be at least a meter. When calculating the area of ​​an element, the type of the entrance door, the opening side of the leaves and the dimensions of the door opening are important, especially when using swing doors. The staircase, in the direction of which the sash opens, is made wider and longer, otherwise it would be inconvenient and unsafe for an adult to manipulate it.

• Fencing

According to the requirements, when designing stairs between floors, cladding structures with a height of 90 cm should be provided. The step between railing balusters is no more than 15 cm. step between balusters not more than 10 cm. There are requirements for entrance porch structures. If they are designed for 3 or more steps, then the height of the fence must be at least 800 mm.

Observe and requirements for illumination of basic structures. SNiP require high-quality lighting steps, especially the first and last elements of the march. In the presence of window openings (according to GOST, if they are placed at the height of an adult), it is necessary to provide for their fencing.

The video below describes in more detail the requirements for the staircase elements. It is told why such dimensions and values ​​were obtained for the railing.

Design and construction of fire escapes

Regulatory documents giving advice on the placement and size of fire escapes does not exist. External constructions are described by GOST R 53254-2009. But since they can be both vertical and marching, there are requirements for their operational characteristics. They are as follows:

• Fences for marching ladders required;
• Vertical structures are equipped with fencing, if their height exceeds 5 m;
• Fire escapes in residential buildings and non-residential buildings with a height of 6 floors or more can only be of a cruising type;
• Production material is metal. Steel grade is selected depending on the climatic conditions in which the structure will be used;
• The width of the vertical design with the fence - from 800 mm;
• March width - 600 mm;
• Fences for marching construction should have a height of 1 meter.

The requirements stipulate the design of fencing for roofs. Their height is 60 cm. Metal elements are tested 1 time in 5 years. In this case, the test load must exceed the permissible by 7-20 times.

Basic regulatory documents for various types of stairs

• II-23-81 - steel objects;
• II-25-80 - wooden objects;
• 35-01 2001 - objects with ramps for persons with disabilities;
• 2.01.07-85 - describes the permissible loads on all staircase elements;
• 2.08.01-89 - design of residential buildings;
• 2.08.02-89 - design of public buildings.

Installation is a long and responsible process. Incorrect calculation or improper installation of parts can significantly reduce the reliability and durability of the structure. For this reason, must be carried out in a certain order, following certain rules.

Installing the stairs to the second floor takes place in stages: first, some elements are mounted, the second ones are joined, then the third, fourth, and so on. Therefore, before installation it is worthwhile to familiarize yourself with the names of the details of the stairs:

• steps - elements on which descent or ascent occurs;
• tread - the horizontal part of the step;
• risers - vertical part of the step;
• kosour - carrier beam, on which the steps are installed on top;
• bowstring - bearing element with notches for steps;
• handrail - staircase fence, preventing falling;
• baluster - the vertical component of the railing (in other words, a column);
• handrail - the horizontal part of the railing;
• playground - free space dividing the stairs to the second floor into 2 or more parts;
• supporting beam (so-called. zero stage) - beam or crossbar, in which the bearing elements rest;
• stand - the main supporting element of the screw design.

Preparation for work

Installing the stairs to the second floor is a long and costly process. To make it as easy as possible, it is necessary to properly prepare. For more convenience, the preparatory work can be divided into 3 stages:

1. design (drawing creation);
2. selection of necessary materials;
3. preparation of tools.

Installation of a spiral staircase: a brief description

Since the shape of the helical design differs from marching varieties, the installation principle is different here.   It is recommended to install such a ladder to the next floor in the following order:

1. drawing up;
2. based on the calculations, the structural elements are made;
3. the lower support unit is installed and fixed to the floor in the chosen place;
4. vertical stand is inserted into the knot;
5. in the stand, the steps are pinched (or put on it);
6. at the floor level of the second floor, a platform is established and the support rod is fixed;
7. balusters are inserted into the holes on the steps, on which rails are put on.

Installation of the finished spiral staircase

Requires a master of careful approach and care. Incorrect calculation or not high-quality fixation of elements may adversely affect the strength and durability of the structure. For this reason, ladder assembly must be done with particular attention.

Ladder marches and platforms are mounted upon completion of masonry at the level of design marks. The intermediate platform and the first march are installed along the laying of the internal walls of the staircase, the second (floor) platform and the second march - at the end of the masonry of the floor.

Prior to the installation of landings and marches check their sizes. Then mark the place of installation, put a layer of mortar on the place of support and set the landing.

Level check horizontal in two directions. The coincidence of the edges of the support edges vertically with the following sites using a plumb line. The distance between the established landings is measured with a wooden template in the places of its support.

In the same sequence, the installation of staircases at the level of interfloor overlaps is carried out.

After checking the site proceed to the installation of a flight of stairs.

Before installing the march, a layer of mortar is applied on the supporting points of the staircases.

When installing the march, one installer is located at the bottom of the support, and the second is on the upper floor or on the scaffold next to the staircase.

The flight of stairs is served by a crane with a fork grab and a four-legged sling with two shortened branches, which, when lifted, give the march a little more than a project slope. When installing a flight of stairs, it is first supported on the lower platform, and then on the upper one. If you do the opposite, the march can break from the top platform. With such a landing, the march may also wedge between the upper and lower platforms.

The installer who is on the upper landing, gives a signal to the crane driver to file a flight of stairs, where he then takes the march and orients him in the right direction, keeping him from swinging.

By lowering the flight of stairs to the lower platform, the lowering stops.

If there are minor deviations during the installation, this is corrected with a crowbar, after which the lines are unhooked, the joints between the march and the plots are grinded with cement mortar and the inventory fences are installed.

Tolerances from the design position of prefabricated staircases and platforms, mm
Marks top of the landing from the project - 5
Sites from the horizontal - 5
From the horizontal tread of the flight of stairs - 5

The minimum dimensions for all landings are the same, because established in accordance with the requirements of state standards. So the minimum width of the platform should not be less than 900 mm, and the length of not less than 2000 mm.

After the installation of the march; establish permanent or temporary fences of marches and grounds.

When arranging the mid-flight ladder, one of the most important and serious stages determining its quality is the installation of marches. Their number and type of installation depends on the type of ladder. On the features and requirements for the installation of staircases consider below.

  Requirements for flight of stairs

Marching staircase is of several types:

• single-marrow;
• dvuhmarshevoy;
• multi-marketed.

The simplest option is the arrangement of a one-marsh ladder, they are typical for low buildings. If the number of degrees in the stairs does not reach the mark of sixteen pieces, then the construction of a one-flight ladder will be relevant for it.

Otherwise, it is required to equip the structure consisting of several marches. Its construction will be more expensive and much more difficult. Multi-mid-flight ladders consist of a certain number of marches that separate special platforms.

There is an order of building codes that apply to the construction of the mid-flight ladder. Marsh is a building construction, which is located in a straight oblique line or curvilinear way. The minimum number of steps in the arrangement of marching ladders is three, and the maximum - sixteen. If more steps, then the construction of a horizontal platform.

The central line dividing the span is called the sunrise line, its location must be at least thirty centimeters from the tread. Therefore, the minimum width of the flight of stairs is sixty centimeters. On such a staircase it is convenient to move only one person. The march requires mandatory fencing with a railing located on both sides of the stairs.

The staircase of the building is called the horizontal part, which is located between the marches. When calculating its size or shape, one should proceed from the average step length of an average person.

We offer to familiarize with the basic requirements for the arrangement of the landing:

• the width of the platform and the ladder must be the same;
• its length is the length of the flight of stairs;
• if the marching elements are parallel to each other, the platform should have a rectangular or rounded shape; if perpendicular, its shape will be in the form of a square.

The most common place for the installation of the staircase is a multistory building. It is during the construction of the flight of stairs in these places most often used structures made of concrete or reinforced concrete. To perform the full range of these works requires the intervention of special equipment.

Before installing the staircase is required to check its high quality. This is done in two ways:

• visual;
• measuring.

With the help of visual inspection detect debris, dirt, cracks, frost - all this is eliminated by cleaning. Using the measuring method, the conformity of the shape and size of the flight of stairs to the geometrically predetermined parameters is checked.

In the process of installation of staircases, each stage of work is carefully monitored, all parts of the staircase are checked, and the installation of the welding and finishing work is completed.

Ladder marches photo:

According to the requirements laid out in special documents, there are maximum permissible deviations when installing staircases:

• with horizontal steps - 0.2 cm;
• with a horizontal arrangement of sites - 0.5 cm;
• with vertical installation of the elements providing the fence - 0.3 cm;
• in the mismatch of the top row of the roof - 0.5 cm;
• the discrepancy between the depth of the reference areas of the horizontal value - 0.5 mm.

Deviations from the norm in relation to the dimensions of the details of the stairs are more than 0.3 cm - with a thickness and up to 0.5 cm - in length. The presence of cracks, flows, rust spots, fat accumulations on the details of the stairs is unacceptable.

The construction of staircase structures begins after the spans are filled with concrete slabs. Fixing the flight of stairs is carried out using cement mortar, the thickness of which does not exceed three centimeters. The solution should be high quality and freshly prepared.

  Calculation of the staircase: features of

Calculation of staircases of sizes is carried out taking into account the load on the supporting structures, which are consoles. Since the ladder is almost daily affected by dynamic loads, the rigidity of the elements of the bearing destination must be of high quality. The value of their deflection should not exceed four hundredth of one span. To calculate the load on the staircase console, one should add the own weight of the structure to the temporary loads; for a residential house, this value is three hundred kilograms per square meter.

Consider that a person uses several times more energy to climb a ladder than when moving along a horizontal straight line. Experts say that in order to correctly calculate a convenient and, most importantly, safe staircase, it is necessary to double the height of the approach to add a width of the step to it, this value will show the average step of the person. If we take into account the step length on the treads, then it is 60-64 cm. Therefore, to determine the tread and the rise, you should use this formula: 2 * А + В = 60-64cm.

In addition, there is an alternative version of the above formula: A + B = 460, in which A denotes the height of the tread, and B denotes its width.

When calculating the tread width, one should proceed from the fact that the foot should rest on it completely, which means it should be at least 20 cm and maximum - 32 cm. The best option is the height of the riser 15 cm, and the step width is 30 cm. If the width of the tread is quite large, then when climbing a ladder, a person will constantly stray, otherwise, with a minimum width of tread, the descent from the ladder will be steep, which will result in injury to people used for its intended purpose.

The ladder march scheme is based on the fact that when calculating the slope of the mid-flight ladder, one should take into account the fact that the best options are values ​​from 24 to 38 degrees. The space in the room that it occupies depends on the angle of the stairs. In the presence of a tilt angle that is less than twenty-four degrees, it is recommended to install a ramp - a flat platform for descent. If the angle of inclination is more than forty-five degrees, then the ladder is constructed folding or side mounted.

The most difficult process in arranging a staircase with a steep slope is to ensure safe descent. If the angle of inclination of the stairs is more than forty-five degrees, then to ensure safety, it can only be started face-down.

When calculating the number of steps should take into account such factors as the height of the floor and the angle of inclination. When determining the exact location of the stairs and the height of the room, it is possible to independently determine the number of steps. To do this, you need to draw a drawing of a flight of stairs, in which a ladder and its main components will be drawn up to a millimeter. The drawing of the flight of stairs is carried out in relation to the height of the flight of stairs.

The height of the floor indicates the distance between the elevations of the finished floors on the first and second floors. For example, when finishing the floor of the first floor laminates, and the second - tiles, you should consider all the layers of decoration, including concrete screed. The standard size of the height of one floor is 280 cm, sometimes 300, 270 or 330 cm. In this case, the ceiling height in the room will be 240 cm. With such a height, it is possible to install a ladder in which the steps meet all safety standards. If there is a different height of the flight of stairs, the height of the steps should be calculated very carefully, taking into account the size of the steps. If there are small errors in the calculations, it is better to distribute them between the first steps, and the size of the other steps to leave the same.

At arrangement of steps, different on height, the ladder becomes traumatic. In the presence of non-standard height of the flight of stairs, it is required to take care of lowering the level of the subfloor of the first and second floors. To equalize the difference between the floor in the house and the landing, the final floor level should be made below the level of the landing. In this case, the threshold will be absent, and the floor will be equipped in an oblique way.

  Staircase device

During the construction of multi-storey buildings, staircases act as one of the main components ensuring vertical connection between the floors. Their installation is a rather laborious process that requires special care and attention.

There are three options for the location of the march:

• straightforward;
• curvilinearly;
• oblique way.

In order to easily remove moisture from the stairs, the lower edge of the staircase must be higher than the first.

In addition, there are several forms of landings, which are:

• tetrahedral;
• multifaceted;
• curvilinear shape.

Installation work on the arrangement of the flight of stairs begins with the reinforcement of surfaces, this process will help protect the stairs from the effects of heavy loads. Since the flight of stairs is influenced by many factors: the force of gravity from its own weight, people and things that move along it, reinforcement is a mandatory process. The reinforcement of the one-marsh ladder is made in its lower part, and the double-marsh structures require reinforcement both from above and below, while the upper reinforced section smoothly passes from the landing to the surface of the steps. Due to the exposure of stairs to high loads, they need to be strengthened in a concrete wall.

The installation of the flight of stairs begins after the leveling. the first span and platform is installed in the presence of the inner masonry of the wall, and the following masonry is already carried out by floor.

  Installation of the landing

The main stages of the installation of the landing:

• implementation of work on marking the site installation site;
• application of concrete solution to the surface of the hard seats;
• direct site installation.

To check the horizontal position of the landing, a building level is applied. To check the interval between the plots, it is required to produce a special wooden template, according to which the check is carried out. Spans on interfloor ceilings are installed in the same way as the site. Installation of a flight of stairs begins with its laying first on the lower section, and then on the top. Scrap helps eliminate minor bugs that occur during installation.

  Installation of prefabricated stairs

Since the manufacture of staircases with your own hands - the procedure is almost impossible, in the absence of a special tool and skills to work with him, it is better to resort to buying a prefabricated structure. In this case, consider the option with a ladder made of reinforced concrete.

This type of staircase marches is absolutely fireproof and is installed on the stairwells. They are installed using cranes, since it is impossible for people to lift such a weight.

The most common option for the staircase is its one-to-two slope, such stairs are the basis of almost any high-rise building. At the same time, there are prefabricated structures with a slope of one to one and a half, they are relevant for cottages or private houses.

There are several types of such marches:

• flat forms, on which there are no frieze steps, but surface ribbing is present;
• ribbed type with the presence of one or two semi-sites.

Their main difference is that the first option uses a reinforced flat pipe as reinforcement, and the second uses a reinforced beam or kosour.

Each staircase involves the individual manufacture of its own landing. There are two types of execution of staircases and platforms:

• left side;
• right side.

Before starting construction work, carefully calculate the size of the flight of stairs and the site. Since their installation is carried out in accordance with the working draft of the project, which clearly indicates the elevation character, the size of the horizontal and installation clearances.

Ladders, in this case, are installed in the process of building walls. Before the start of installation work, it is required to check the staircase and the site with the help of a tape measure. Next is the manufacture of their wooden template, which is identical to the natural version, it copies the supporting components of the stairs.

Next on the wall marked the place of installation of the site, applied the solution and its installation. The next process is to check the flatness of the installed site. If the site is installed incorrectly, then scrap or offsetting with a crane is used to correct it.

If the site does not match, in advance of the calculations, the installation of the flight of stairs will end with its failure or location in a curved position. To verify the accuracy of the installation site, it is recommended to use a template made of wood.

The flight of stairs is carried out with the help of a crane, which in the process of lifting make it slightly inclined. If the mounting loops on the march are missing, then a forks are used.

Before installing staircases, a bed is made on the basis of a cement-sand mixture. It is located in the field of the reference destination, the application takes place manually, with the help of trowels.

To install a flight of stairs you need at least three people, one of whom stands on the lower platform, and the second on the top. The third - acts as a driver. As the flight of stairs moves, the first person to receive it is on top. 35-40 cm before landing, the march should be firmly pressed against the wall and sent to the stairwell. First set the lower part of the march, and then the top. With the help of scrap, minor defects are corrected and the march is disengaged from the crane. The seams between marches and staircases are covered with a monolithic solution. When you install the march in the opposite position, first the top and then the bottom - it will fall off the ground.

When working in low-rise buildings in the form of cottages, the reinforcement of reinforced concrete stairs takes place in open staircases. To save space, there is the option of no landing. In this case, on the stairs go up and go directly from the concrete floor. The flight of stairs rests on the surface of the bearing lintel or reinforced concrete beam. In no case is it allowed to support the floor slab on the surface of the slabs. The height of the jumpers depends on the total thickness of the floor covering to be installed.

The standard appearance of the marches implies the presence of smooth reinforced concrete steps, which are further trimmed with marble or granite treads. They go in picking to the stairs. This material and trim stairwells. Note that the tread is taken into account when calculating the height of the finished floor. When organizing the entrance to the building through the staircase, the first intermediate platform requires the organization of a basement march of three to six steps. In such cases, constructions consisting of stacked reinforced concrete steps are used.