Interfloor staircase: Part two

The design of any structural structure, including stairs, begins with calculations. It is better to spend time on paperwork than to then spend money on correcting errors and shortcomings in a finished structure. Correctly performed calculations will not only save the budget allocated for construction, but will also speed up the work.

The staircase calculation consists of next stages:

1. Preparation of initial data for calculating an L-shaped staircase with an intermediate platform, based on the opening dimensions of 300x150 centimeters
2. Determining the number of steps on a staircase
3. Determining the height and width of the intermediate platform
4. Determining the width of steps
5. Interim results of the calculation of an L-shaped shape with an intermediate platform, based on the dimensions of the opening 300x150 centimeters
6. Determining the dimensions of a staircase opening

L-shaped staircase with an intermediate platform for an opening of 300x150 cm: Start of calculation

As already mentioned in the first part of the article “Design and calculation of the interfloor staircase of a private house. L-shaped staircase with an intermediate platform”, the calculation of the staircase must be performed before the start of construction of the building. The calculation will require certain data from regulatory documents that will help verify the correctness of its implementation.

We calculate the staircase taking into account the space limitations for its installation. For example, due to the length and width load-bearing walls at home it is not possible to make an interfloor opening more than 300 centimeters long and 150 centimeters wide. The length of the room is 450 centimeters (along the wall with the opening), the width is 340 centimeters (along the wall perpendicular to the opening).

Note:

The calculation of the interfloor opening itself is omitted, but, at the end of this material, a method for determining the size of the interfloor opening will be considered.

At first glance, it may seem that an opening length of 300 centimeters is quite sufficient to construct a safe and comfortable staircase. Whether this is so will have to be checked using the calculations below, which will help you find out what kind of staircase you will get.

Determining the number of steps in a staircase

To determine required amount steps, the following auxiliary table is used, which shows the height of the steps depending on their number and floor height:

Table 1. Correlation of floor height with the number of steps of the staircase.

The height of the floor of the building is 295 centimeters, taking into account the overlap (according to table 1, we focus on 3000 mm), judging by the table, optimal quantity There will be 15-16 steps for such a staircase, with a rise height of 18-20 centimeters. At the same time, it should be noted that it is necessary to choose such a number of steps that the width of the steps (tread width) is ensured, convenient when moving along the stairs; it is this number that will be optimal.

The last (frieze) step of the upper floor will be located at the level of the finished floor of the second floor. Therefore, when determining the number of steps, it is necessary to take into account the thickness of the material that will be used to make them - in this case, equal to four centimeters. To find out the height of the steps, we will carry out the following calculations:

(295 – 4 (room height – material thickness)) / 15 steps = 19.4 centimeters

Taking 15 steps as the optimal number, in further calculations it is necessary to make sure that this choice is truly optimal.

Rice. 1. Angle of inclination of a single-flight staircase.

In addition to the fact that there is a limitation on the height of the platform from the floor level, the angle of inclination of the stairs will be steeper, the wider the intermediate platform and, accordingly, the stairs. It is necessary to solve two problems - firstly: the angle of inclination should not exceed 42°; secondly: the width of the site should not be less than 80 centimeters.

Figure 2 shows a diagram of changes in the angle of inclination depending on the width of the stairs and the height of the landing level of 95-100 centimeters, from which it can be seen that the width of the stairs and landing should not exceed 80 centimeters.

Now we know how the width of the intermediate platform and stairs affects the angle of inclination. Next, you need to determine to what height the intermediate platform can be raised. The recommended clearance at the critical point of the rise between the step and the ceiling is 200 centimeters.

The following formula is used for calculation:

200 cm (clearance size) / 19.4 cm (step height) = 10.3 steps (rounded to 10).

From the obtained result we can conclude that a staircase opening 300 centimeters long will include an upper flight of 10 steps with an intermediate landing 80 centimeters wide. The remaining five steps will be located in the lower flight of stairs, accordingly, the platform will be located at the level of the fifth step of the first flight of stairs.

For further calculation, a formula is used to determine the height of the site level:

(295 cm (height of the room taking into account the ceiling) – 4 cm (thickness of the step material) – 10 steps x 19.4 cm (height of the steps)) = 97 cm (taking into account the thickness of the step material – 101 cm).

Rice. 3. Determination of the height and width of the intermediate platform.

Transferring calculations to the diagram

All calculations obtained are plotted on a diagram of the room, as is done in Figure 3. As mentioned above, to draw up a diagram it will be convenient to use paper with a millimeter grid, which will make it easier to draw it on a certain scale, for example, 1:10. Walls A and B in the diagram are located in the same plane. The width of the platform is marked on the walls as 80 centimeters. A gap of 5 centimeters must be left between the stairs and the surface of the walls. Four centimeters are measured from the floor level (the thickness of the step material) and a horizontal line (X) is drawn.

Next, a distance of 19.4 centimeters is measured from the line (X) and the next horizontal line is drawn, and so markings are applied with an interval of 19.4 centimeters to the floor surface. All steps are separated by horizontal lines, as shown in Figure 3.

Then, from the upper frieze point, you need to count 10 steps, which along wall A will enter the staircase. When all horizontal lines carried out, you can proceed to determining the critical point of the rise: along wall B, the distance is measured from the intersection of the interfloor ceiling with the beginning of the staircase opening to the critical point of the passage (Y) (Figure 3, right), where the width of the opening is 150 centimeters. It is clearly seen that taking into account the material thickness of 4 centimeters (in the red circle) from the level of the third stage at the criticality point of the lift, a distance of 207.7 centimeters is obtained. This figure is more than the recommended 200 cm, therefore, the entire calculation and selection of the height of the site was completed without errors.

Determining the width of steps

Now, having a reference point of maximum height for installing an intermediate platform, it is necessary to continue designing the staircase, drawing it on the diagram. The next task is to determine the width of the steps.

Rice. 4. Tread calculation scheme

The opening included ten steps and an intermediate platform 80 centimeters wide. The width of the steps is determined by the formula:

215 cm (distance from point A to the platform) / 10 steps = 21.5 cm (step width)

From point A to the right (indicated by the arrow), you need to measure 21.5 cm and draw a vertical marking line. The resulting value will give the width of the step; in the same way, you need to measure and draw the remaining vertical lines, as shown in Figure 4.

From the point of intersection of the lines marking the width and height of the steps to the landing, it is necessary to draw a diagonal line indicating the axis of inclination of the stairs; the resulting inclination angle should be about 42°. If all dimensions are made to a certain scale, the angle of inclination can be checked by measuring it with a protractor. The slope line is highlighted in blue.

Next, highlight the steps of the staircase in red and connect with an L-shaped line the marking lines along the width and height of the step (a square divided diagonally). In Figure 4 you can see that there were 15 steps and an intermediate platform. The upper flight contains 10 steps, the lower flight - 5 steps.

The resulting step width was 21.5 centimeters, which is not enough for safe and comfortable movement along the stairs. When arranging steps to ensure safe movement, use simple formula: width + height of the step = 45 cm ± 2 cm (43...47 cm), according to the calculation it was obtained: 21.5 cm (width of the step) + 19.6 cm (height of the step) = 41.1 cm.

Method of overhanging steps

For this case, the easiest way to increase the width of the tread is to overhang the steps, one over the other, by 1-5 cm. This option is usually used in cases where it is not possible to increase the width of the steps in any other way.

To determine optimal width steps for this case, it is necessary to decide on the amount of overlap of the step above the step. To do this, a simple calculation is carried out using the formula:

45 cm - 19.6 cm (step height) = 25.4 cm (rounded - 25.5 cm) - this will be the width of the step with an overlap, and the amount of overlap is:

25.5 cm – 21.5 cm = 4 centimeters

Consequently, to construct steps you will need material that is not 21.5 centimeters wide, but larger - 25.5 centimeters. The final calculation using the formula that determines the safe parameters of the steps of the stairs gives:

25.5 cm + 19.6 cm = 45.1 cm – the value corresponding to the formula for calculating the proportional parameters of steps optimized for safe movement on stairs. After this, it is necessary to reflect on the diagram the increase in the width of the steps, and at the same time, draw the thickness of the material of the steps, equal to four centimeters.

Rice. 5. Diagram showing the increase in the width of steps

Horizontal markings of the thickness of the steps, starting from the upper frieze step, taking into account the thickness of the material of four centimeters, are applied to the diagram as shown in the figure. Then a vertical marking is applied, indicating the additional width of the steps, also equal to four centimeters, its application begins from the same upper frieze step. In Figure 5, the yellow color indicates the width of the steps, 21.5 cm, obtained in the calculation; the red color indicates the additional width of 4 cm. Ultimately, the resulting steps are 4 cm thick and 25.5 cm wide.

Now we need to turn to the table containing the recommended ratios of the width and height of the steps:

Table 2. The ratio of the sizes of the steps of the stairs.

Table 2 green Size ratios that are convenient for comfortable movement are highlighted. Easy-to-move size ratios are highlighted yellow, and for a relatively convenient one - in blue. The size of the steps 25.5 cm x 19.6 cm, obtained as a result of the above calculations, corresponds to regulatory requirements, but since the width of the steps is obtained by increasing them by overhanging with an outlet four centimeters above each other, this makes the staircase convenient only for ascent; for descent it is relatively comfortable.

Interim result of calculating an L-shaped staircase with an intermediate platform for an opening measuring 300x150 centimeters

Subtotal

Summing up the intermediate results of the obtained calculation results, we can say that the dimensions of the staircase obtained during the design comply with regulatory requirements, but the staircase, nevertheless, turns out to be only relatively convenient, due to the fact that there was a limitation on the size of the interfloor opening:

Rice. 6. Example of ascending and descending a designed staircase

The maximum permissible angle of inclination of the stairs was obtained equal to 42°.

The width of the steps due to the overlap of four centimeters makes the steps of the stairs relatively convenient for descending. This is due to the fact that when descending, due to the steps hanging over the step by four centimeters, their working width will not be 25.5 cm, but 22.5 cm (Figure 6), that is, at least 3 centimeters of the working width are lost width of steps.

Rice. 7. General drawing L-shaped stairs with an intermediate platform.

On general drawing projections of an L-shaped staircase with an intermediate platform; the results of previous calculations are summed up. The drawing allows you to look at the results of calculations in a three-dimensional format and get a clear idea of ​​the results of the work performed.

Rice. 8. L-shaped staircase with an intermediate platform. Side view.

Rice. 9. L-shaped staircase with an intermediate platform. View from above.

Figures 8 and 9 show the calculation results in volumetric format. It can be seen that there are no balusters, handrails, fences, etc. yet. All this still needs to be calculated and, in addition, a design solution for the staircase needs to be developed - what kind of stringers to make, what material to choose for making the steps and much more. Thus, only about half the way has been completed, but even now you can see the staircase, the design of which was discussed in this and the previous articles.

Now you can analyze the results obtained and find out why the staircase turned out to be conditionally comfortable. The answer lies in the size of the interfloor opening, limited to a length of 300 centimeters. According to existing rules, the calculation of a staircase begins by finding out the length of the opening required for it or, to put it simply, the opening is adjusted to fit the staircase, and not the staircase to fit it.

Let's go back to the already designed staircase and try to calculate it again:

The calculation was based on limiting the size of the interfloor opening, which led to the need to install 15 steps with a height of 19.4 centimeters. With this staircase arrangement, it will not be possible to reduce the lifting height. Now you need to calculate what a comfortable staircase should be like, if you discard the restrictions.

Determining the necessary parameters of a staircase opening

To do this, you need to return to Table 2 of this article and take two other indicators of the parameters of the steps to calculate the length of the opening - those where the staircase has step parameters that are convenient for both ascent and descent, for example: 19x26 centimeters (15 steps) or 17x28 centimeters (17 steps).

The calculation is carried out using a simple formula:

width of steps X number of steps = length of opening.

Substituting numerical values, we obtain the following values ​​for the opening length:

26 cm x 15 = 390 centimeters or 28 cm x 17 = 476 centimeters

From the obtained values ​​it is clear that the most the best option there will be 15 steps, and the width of the opening for constructing a comfortable staircase in this case will be 390 centimeters. Hence the conclusion that confirms what was said earlier - first the staircase is designed, and only then the opening parameters are calculated, but not vice versa. Of course, this classical method is only applicable when there is available perfect option, in which the area and layout of the house allow calculations to be made in this order, and not as in the above case with size restrictions stairwell.

Limited opening dimensions

In the case of limiting the size of the opening, it is also possible to make more comfortable staircase L-shaped with an intermediate platform. To do this, it is necessary to change the way the staircase is attached to the interfloor opening. Previously, we considered a design option in which the upper frieze step is located flush with the level of the finished floor of the second floor; in the new version, we will be able to reduce the required number of steps if we lower the upper frieze step below the floor level of the second floor and instead of using the end fastening of the staircase to the interfloor opening, use a ceiling one. It should be noted that such a change in the method of attaching the ladder to interfloor covering will necessitate repeating all calculations.

With this design option, which will be further referred to as the second staircase design option, it may be necessary to install risers, but almost the entire staircase will be closed, which can also provide certain advantages. How to calculate an L-shaped staircase with an intermediate platform with previously specified parameters of the staircase opening and room according to the second option will be discussed in the next article.

After calculating the second design option for an L-shaped staircase with an intermediate platform, the next article will discuss the further structure of the staircase - balusters, handrails and other, relatively small, but important details. The work on the calculations has not yet ended, but we already need to think about its final completion - the development of an original design solution for the staircase, which will make it something more than just functional design providing access to the second floor of the building.

A staircase opening is an opening in the ceiling intended for the installation of stairs. During the process of making the opening, a section of the flooring is removed, the beams are cut and part of the ceiling is removed. This article discusses in detail what a staircase opening is: its structure and the correct calculation of dimensions.

Peculiarities

The opening for the stairs to the second floor must include a free area below. Its length should not be less than a meter, and in the case where there are several doors on the site, then much more, because this will ensure the possibility of simultaneous opening of the doors and the safe rise of a person upstairs, and will eliminate a sudden collision.

There are cases of blocking the opening in small attic spaces. A folding type design is used here, complete with a hatch covering the entrance to the attic.

The width of the staircase opening is determined by the width of the flight. For a single-flight structure, the width of the hole is equal to the width of the flight, taking into account the gaps for fastening the fence. For a two-flight configuration, double the flight width is used. The length of the hole is calculated depending on the slope of the stairs. It is customary to take into account a distance of 2 meters from each step to the ceiling, and where this distance becomes smaller and a hole should begin, the length of the opening is less than the length of the flight by about a meter.

A hole in the ceiling for an ordinary staircase is made rectangular shape, and for a screw – round. It should be designed to suit the average height of a person.

A person climbing up should not touch the ceiling with his head while standing on any step. Golden Rule builders: the larger the staircase opening, the more comfortable the staircase, and the smaller, the riskier its operation. It is also necessary to properly strengthen the opening itself so that the floor slabs of the upper tier do not collapse in the future.

Kinds

Depending on the type of staircase itself, the availability of free space and design solutions the rise to the second floor may have different design. The following types of staircase openings are found:

• Round opening. It wins outwardly with its neatness and fits very elegantly into any interior. It is suitable for spiral staircases, but here it is important that the upper steps fall directly under the circle itself.
• Rectangular version– this is a classic design for average private homes. It is the easiest to design and subsequently finish. The length of the opening in this case directly depends on the size and design of the flight of stairs.
• Semicircular or oval the opening can be used for spiral staircases, in particular, spiral ones with different turns.
• Non-standard an opening of all possible shapes from trapezoid to polygon is considered. This is not a forced measure, but more often the owner’s desire to get unique interior or just a flight of fancy of designers and decorators. To embody such an unusual design idea very difficult, but the result can exceed all expectations.

Dimensions

With a straight type of device, the angle of inclination is less than that of a rotary product. The size of the opening also depends on the type of staircase: a straight staircase requires a larger opening than a spiral or folding one. After the dimensions of the opening are determined, 5 cm are added to them on each side - this is done for subsequent convenience when finishing the site after installing the stairs.

The staircase opening is calculated based on parameters such as:

• design model;
• height of required lift;
• square;
• tilt angle;
• number of steps.

When calculating the area for the construction of a staircase opening, the layout of the lower and upper tiers is taken into account. The site for installing the steps is determined in advance and the boundaries for the opening are outlined.

To determine the required amount of space in length and width required to arrange the exit to the next floor, it is necessary to perform a series of calculations. The staircase structure is directly predicted: its slope, the number of steps and the configuration of the model are determined.

A standard set of indicators is also calculated:

• length of the stairs;
• width of the stairs;
• span height;
• tread depth;
• riser height.

The gap between the finished floor level of the two floors acts as the height. When determining the number of vertical parts of a step, it is necessary to take into account the recommended value of their height parameter, which varies from 15 to 18 cm. Deviations of up to 12 or 20 cm are acceptable. When determining the number of steps, the result must be rounded. The number of steps will be the quotient of the total height divided by the size of the riser.

As the quantity increases, it is divided into 2-3 flights, which must be separated by flat and turning platforms.

In the case when the top floor of the house is represented by an attic or the exit is to one of the rooms, an opening 0.6-0.7 m wide is sufficient, which is great opportunity save money free space. If you need access to a hall that unites several rooms, then for convenience and comfort during operation you need an opening width of at least 0.8 m.

Taking into account the height of the span and the size of the steps, determine the maximum permissible distance to the ceilings. To do this, use the following algorithm with formulas:

• Determine the distance from the floor to the upper floors by calculating the difference in the interval between the floor of the first floor and the floor thickness of the floor.
• The height of each step is subtracted from the resulting value in turn.
• Stop calculations when the result is less than two meters. In this case, the number of steps taken away will be under the ceiling, and the remaining elements will extend beyond the boundaries of the opening.

To successfully install a ladder in an already installed ceiling, it is necessary to increase the angle by increasing the lifting step. In addition, by calculating the opening under the stairs, you can slightly reduce the size of the tread. In some variants modular stairs The tread size can be up to 16 cm.

It is also necessary to take into account such parameters as:

• Location of the opening. During installation, it should be taken into account that the floor area will be significantly reduced. Most suitable option the structure is considered to be located parallel load-bearing beams. The opening is located near the wall, so the beams are fixed at one end to the wall.
• Width of the structure. If climbing stairs involves access to one room, then a width of at least 0.6 m is acceptable. If there are several different rooms, then the width of the opening should increase.
• The length of the stairwell. The distance between the beam in the ceiling opening and the steps of the stairs must be at least two meters.

When designing, it is important to consider the following indicators:

• geometric shape and size of the opening;
• room height;
• thickness of the interfloor ceiling;
• maximum permissible dimensions future design;
• slope of a flight of stairs;
• the depth of the created steps;
• method of fastening fences.

Taking into account that the optimal step depth parameter reaches 28-32 cm, an accurate calculation will be required. According to regulatory documents you will need the sum of the height (h) and depth (b) of the steps in plan, equal to 47 cm. The tread depth is determined by the formula:

b = 47 – h.

Considering the minimum standard passage height of two meters and the width of the march of at least 0.6 m, the opening should be approximately 2x2.5 m. With these dimensions, you can provide the most favorable angle of inclination, which ranges from 30 to 45 degrees.

Device

Making an opening for a staircase should begin by calculating its area and type. The design can be of a curved or marching type. Marching is considered a direct option with or without platforms. The curved configuration is available in rotary and screw versions.

When choosing the size of a structure you must:

• take into account the floor layout;
• determine the site for installation of the stairs;
• outline the boundaries of the future opening.

To make an opening for the stairs, it is necessary to carry out the following work:

• Draw up a project taking into account all dimensions and types of construction. Take into account the material for the stringer or bowstring, the angle of elevation. Calculate the number of ordinary balusters and the size of the railing.
• Calculate the rise of the step.
• Remove the coating on the floor and ceiling along the contour according to the dimensions corresponding to the future hole. Remaining materials may be useful for subsequent finishing of the structure.
• Remove parts of the beams and then connect them to the remaining beam elements. To strengthen the structures, cross bars with a cross-section similar to the main beams are added. The structure is attached using metal corners along the length of the sides of the stair opening.

• Fix the reinforcing beams on each side of the future hole.
• Install support beams on the jack stands at a distance of at least 50 cm from the reinforcing ones.
• Make holes in each of the corners of the drawn plan for the cross beams.
• Saw down the vertical part of the steps. Place the outer and outer parts of the stringer of the second segment of the wooden device.
• Fix the edge of the cross beam and the sawn part and connect the longitudinal beams to the brackets, securing them at the joints.

Measurement must be carried out carefully and leave room for everything required clearances, which will then need to be closed. The framing can be made to your liking.

Opening in iron concrete floor. The design of an opening in a concrete slab has a number of features. The place for it must be prepared in advance - even during the construction of the floor itself. It is important to take into account the limitations of vibration effects, exceeding which can lead to the appearance of cracks. To make the opening you will need support beams in the form of bowstrings or stringers, support pillars, placed for screw structures, steps and railings with balusters and handrails.

It is necessary to carry out the following technological operations:

• Install steel beams parallel to the floor slabs.
• Weld the elements into a frame supported on the wall of the house.
• Reinforce areas, which are then filled with concrete.
• Make a shield on the floor for the bottom of the formwork. Using ropes, lift it up and attach it to the formwork beams.
• Make wire loops and throw them over the beams.
• Attach the formwork panel to the adjacent floor slabs by twisting the wire.
• Cover the shield with polyethylene to avoid contact with the solution.
• Pour in the concrete or bitumen mixture; the twisted wires should remain inside.

Very often, when a building requires expansion of living space, the attic space is turned into a room, but at the same time there is a need to install a staircase that will connect it with the rest of the living space.

This need also arises if we're talking about about a two or more storey building. In order to build interlevel staircase, you must first break through the staircase opening in the ceiling. Photos and descriptions of the process will be presented in this article.

Preparing for the arrangement of the staircase

Before you get started, there are a few things you need to think about important points, on which the success of the entire enterprise will directly depend:

Location of the hole. The location of the opening should be carefully considered, at the same time taking into account that the floor will become noticeably smaller, because In order to turn normally when walking up the stairs, you need to leave a space between the wall and the upper and lower steps that is not narrower than the stairs themselves. Its optimal location is considered to be one in which the hole in the slab runs along the beams.

Width of the stairs. If there is one room on the floor to which the staircase leads, then it is made at least 60 cm in width. But if there are several rooms on the floor, then it is made wider.

The staircase opening cut into the slab must be of a length that leaves sufficient space between the ceiling and the steps.

The distance between the edge beam limiting the hole in the ceiling and the steps must be at least 2 m. This determines the ease of use of the staircase.

The size of the staircase opening. When deciding on the dimensions, you should take into account the type and design of the staircase that will subsequently be installed. To install a straight staircase you will need much more space than, for example, a spiral staircase. Having decided on the length and width of the staircase opening, you need to add 5 cm on each side for finishing.

Before you start making a hole in the ceiling, you need to partially dismantle the floor covering, cut the beams and remove the ceiling section. Flooring boards should not be thrown away because... they may be useful in further work.

Cutting a hole in a wooden ceiling

To make a hole in a wooden ceiling you will need not that much complex instrument, For example:

a circular saw;

self-tapping screws;

screwdriver;

wooden beams;

metal corners.

If the hole for the opening is cut in indoors residential building, then the beams that form it must be fastened between the floor beams.

Actions must be carried out in this order:

in the section of the floor where the opening will be located, it is necessary to cut one beam or two, if there is not enough space, but more than this amount cannot be cut due to the risk of collapse;

attach paired beams, to which 2 more beams will then be attached, forming an opening parallel to the beams running in a row. After this, short ones are attached to them, providing greater rigidity and strengthening the structure. The dimensions of the paired beams must exactly match the main ones;

all elements are connected to each other using metal corners and self-tapping screws. It is also possible to use a profile for fastening. If the opening opening is in close proximity to brick wall, then the beams should be fastened with one side into it.

Making an opening in a concrete slab

To create an opening in a concrete slab, you should stock up on the necessary tools and materials, namely:

metal profiles;

metal corners;

welding machine;

• fittings;

  wire;

  rope;

  mesh for plaster.

The work is carried out in the following sequence:

Making a hole in a concrete floor yourself is very difficult. Its arrangement must be taken care of even at the stage of manufacturing the slabs. But if this point was not taken into account when designing a house, and a ladder was still needed, then to cut through the slab it is better to use the services of special licensed organizations that have necessary equipment and knowledge of how to do it safely. The opening is framed with special steel profiles.

• On the other hand, if you have a high-quality, powerful hammer drill and a large grinder, you can do the work yourself. To begin with, a special disc for concrete is used to make an incision along the perimeter of the hole (half the thickness of the slab), then, using a hammer drill, separate pieces of the floor are hollowed out. This is done so that when they fall they do not damage the floor.

The hole for the opening is formed using concrete slabs having standard width. In this regard, it turns out to be the same in width. Openings for stairs take up much less space than slabs; therefore, the resulting holes on both sides are sealed. Along the slab, as in the previous case, metal beams are installed, which are welded to each other. The metal profile frame is fixed in the wall.

After this, the bottom of the formwork is assembled, lifting it with ropes to where it will be installed. Beams can be replaced with boards placed on edge and long-length reinforcement. Next, wire loops are thrown over them, and mounts are installed between the branches of the wire. After this, the wire is twisted.

The formwork is pulled to the slab and pressed. To cement mortar if it does not leak out, it is wrapped in polyethylene.

The twisted wire remains in the concrete mass. When making a steel frame by welding, the shelves of profiles located lengthwise are directed into the slab. This allows you to minimize labor costs in the manufacture of monolithic sections. The shelves of the transverse profiles can be positioned as you like, this does not play such a big role, but still, if in the future you plan to finish the hole with wood, then they should also be directed inward. When a monolithic section is being made, the cement mortar will go under the profile and cover the metal parts. To ensure that it remains reliable for a long time, short pieces of metal are welded onto the lower flanges of the profiles, onto which a mesh for plaster is attached.

In order to save money, the structure obtained by welding is replaced with a blockless one, without using longitudinal beams. The edges of the hole are covered with metal corners that will rest on the ceiling. But this method acceptable only if the staircase you plan to install is narrow. If it is wide, then it is not worth using.

Finishing the staircase

When the opening is ready, more work will need to be done on it, to bring it into this form, after which the decorative finishing and installation of the staircase will begin. This must be done in the following order:

First of all, you need to cover the floor from the bottom with plasterboard. If this is not done, then it will not be possible to calculate the size of the side slopes in the opening. It is better to install drywall on metal profiles, and not on the overlap itself. If the drywall is attached directly to the ceiling, then the entire load falling on it will be transferred to the sheathing, which over time will wear out in those places where the screw heads stick out. If the sheets are not adjacent to the floor plane, then the load will occur only at those points where the suspensions are attached to the ceiling. Thus, no deformation occurs. And yet, it is convenient to place electrical wires in the gap formed between the slab and the casing.

At the end of the previous stage, the outline of the opening will be indicated. Now you can attach the side slopes to it with self-tapping screws. It is worth attaching perforated metal corners to the edges to protect the corners and give them clarity. It is better to do this with a stapler and staples. After this, they are coated with putty.

This is followed by finishing the walls of the staircase opening. There can be many options here, depending on your imagination and material capabilities: paste wallpaper, attach plastic panels, decorate with tiles or stone, just paint.

In the process of cladding to achieve best result, you need to follow a few simple tips:

if façade putty is used during cladding work, then, when decorative finishing, it will be possible to use many more options, because it is the most reliable;

if you want to subsequently cover everything with clapboard, then you should not line the slopes with plasterboard;

after the putty layer has been sanded, it should be primed;

wires and communications that will be hidden between the ceiling and the cladding should be placed in non-flammable boxes.

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The staircase is a complex building structure. It should, first of all, be highly secure, and only then play the role of additional decoration of the room. In the case of building a lifting structure, you need to know how to calculate the opening for the stairs to the second floor.

Purpose

In the case of building a new house, the location of the lifting structure is determined by its technical project. To install it, an opening of a certain size is left in the floor, where the staircase structure will subsequently be located. However, there are isolated cases when the required location of the stairs was not taken into account by the owners of the house. Then you will need to prepare a hole for the stairs in the finished floor, as shown in the photo.
This is possible if the descent into the cellar is not thought out, and also if the staircase structure is installed in the bedroom, etc. Therefore, you will need to cut a hole in the floor covering, and then install several new beams along its boundaries.

Defining the parameters

Before you prepare to cut a hole in the floor, you need to think it through in detail. optimal place location. It is also necessary to take into account that the floor area obtained upon completion of the work will be significantly reduced. The optimal option would be when between stair steps and the wall will remain a distance that will be equal to or exceed the width of itself staircase design as shown in the photo. Then its use will be comfortable. It will also be convenient to locate the stairs to the second floor when the hole lies along the beams themselves.

Strictly follow the building standards that determine the basic parameters of a safe and durable product:

• its width should not exceed 600 mm if the design allows you to be in the same room;
• if it can be used to get into several rooms, then it should be wider than 800 mm;
• It is worth choosing the length of the hole for the stairs so that a space of at least 2 m is formed between the ceiling and the top step;
• for ease of operation of the structure, it must have a fairly spacious clearance.

The type of construction determines the parameters of the opening. Keep in mind that a straight staircase will require significantly more space than other staircase options.

Device

As soon as you decide on the dimensions of the staircase opening, add another 50 mm to its parameters. This is necessary for further execution finishing works. Now you can get started:

1. Remove part of the floor. In addition, part of the ceiling of the floor below will have to be dismantled. However, there is no need to rush to throw away the remaining materials - you may need them to finish the structure;
2. Arrangement of the opening of the future structure involves removing part of the beams and then connecting them with the remaining beam elements. The beams located across the opening must meet the characteristics of the main beams. The structure is attached using angles along the length of the sides of the stair opening;
3. The ceiling of the floor below will need to be drawn. Don't forget to add a few more centimeters to each of its parameters. This is necessary for future finishing;
4. Then fix the reinforcing beams on each side of the opening and outside the narrow sides of the future opening;
5. Install the support beams on jack stands no closer than 50 cm from the reinforcing ones;
6. Make holes in each of the corners of the drawn plan;
7. Next they move on to cutting out the staircase hole. Going up to the second floor, identify the holes that were previously drilled. And from each of them draw a line 100 mm in size, as shown in the photo. The hole for the cross beams will run along this line;
8. Having made cuts in these places, also make cuts parallel to the floor boards;
9. Remove the sawn parts;
10. Double transverse beams are made from the resulting pieces. They will make the opening of the structure much stronger and more reliable. This will significantly increase the service life of the structure and significantly secure it;
11. Fix the edge of the cross beam and the sawn part together, and then connect the brackets and longitudinal beams;
12. Fasten the brackets at the joints between the sawn-off and cross-beams, and attach the latter to the ends of the sawn-off beams;
13. Following this construction technology, another beam is being installed, lying across the opening of the structure;
14. If the product borders a wall, embed one edge of the cross beams directly into the wall. Using special Building tools, holes are cut on the wall surface for subsequent installation of the ends of the double cross beams.

In old classic English-language detective stories, the plot very often revolves around falling down the stairs. This type of accident is still common today. Since the second level is becoming commonplace not only for country house, but also for urban housing, the issue of competent design of stairs - reliable and safe - is becoming more and more relevant. Important stage designing a staircase - competent calculation of its main parameters.

At the house design stage

The higher the quality design work, those less problems arises during the execution of work, the easier it is to calculate the expected costs and the better the final result. This is considered an axiom, but for some reason in construction practice it happens differently. This is especially important for creating convenient and safe communication between different residential levels.

Thoroughly work out the future staircase better in the earliest stages of design. Squeezing the necessary staircase structure into an existing, but very narrow opening in the ceiling is a very problematic matter. Therefore, it is better to determine in advance on the floor plan the optimal location for the opening and calculate it required size. Moreover, for such important element buildings must provide sufficient lighting (preferably natural) and the possibility of reliable fixation load-bearing elements stairs to building structures. It’s best to do all this at the development stage internal layout and the choice of technology for constructing future housing.

Initial data

In order to pick up optimal sizes stairs to the second floor, necessary determine the initial data:

Other data will be needed for detailed study. In particular, the choice of staircase design is influenced by the material of the walls and ceilings, not to mention taking into account the overall design concept of the room. But first you need to calculate the line of travel, the height of the step and the length of the tread.

The main thing is safety

The popularity of the plot device among Agatha Christie and her followers in the form of characters falling down the stairs is largely explained by the tradition of use in England and America (as well as in Japan) staircase inclination angle 45 degrees, i.e. the length of the tread is equal to the height of the step. This achieves the greatest savings in the area occupied by the staircase in the plan. Domestic recommendations from experts call for considering this case as the most extreme possible, because the ascent, and especially the descent from floor to floor along such a flight, is safe only for a person in good physical shape and wearing comfortable shoes.

A lower step and a tread longer than 250 mm is not only safer, but also more comfortable. It has been proven that when going up to the second floor, it costs less effort, and this is especially important for an elderly person.

Basic theory

Experience and science have developed some optimal parameters for tread and riser (in mm): 150x300 and 170x290. The first is recommended for external (landscape) stairs, the second - for internal ones. Optimal slope stairs - from 30 to 40 degrees.

If you are calculating a staircase for an existing building, you should use special formulas that use the following data:

The calculation of the parameters of the stages is done using 3 basic proportions:

1. "Comfort formula": a - h = 120 mm
2. “Safety formula”: a + h = 450 mm
3. Blondel formula: 600 mm

The third equation is considered the most universal, i.e. suitable for most cases.

François Blondel proportion

The 17th century French architect and engineer François Blondel (1618–1686) was one of the first to look for a mathematical relationship between the parameters of the human body and the architectural elements of a building. His research underlies many modern ergonomic theories of architecture and design.

It is more convenient to start calculating steps according to Blondel by calculating the height of the step. The height of the interfloor rise is divided by the estimated number of steps, and a result is sought that is closest to the optimal value - 170 mm for internal and 150 mm for external stairs. Then, using the formula, the length of the tread is found and the total length of the staircase stroke is calculated. If there are restrictions on the overall dimensions of the space under the stairs, the maximum tread length should be derived from this indicator, since this is the main indicator of convenience and safety.

Designs with winder steps (these are those in which one edge, located at a smaller radius of rotation of the staircase, is narrower than the other) and, especially, spiral staircases consisting entirely of such steps are one of the most interesting and impressive in design and constructive solution. But straight steps with turning areas are much more comfortable and safer, and steps that are rectilinear in shape are also much cheaper than curved ones.

But if the size of the opening and space for the stairs allows the construction of only a rotary structure, the calculation of the winder steps is carried out along the central line of the march, plotting the calculated tread length along it, and the middle line cannot have radius of curvature greater than 30 degrees. The standards provide for a minimum tread width along the center line of 260 mm, and the width of the narrowest part of the step cannot be less than 100 mm.

You should remember one more feature of the human body, which should be taken into account by competent calculation of the stairs. The length of a step taken with the right foot is on average 2 cm longer than that taken with the left, and the safety of the stairs should be assessed by the descent - in this case, the area under which the foot can be supported is smaller by the amount of the overhang (“nose”). Conclusion - the left approach to the turning section of the stairs is more convenient.

In one march you should not make more than 10 ascents; then you should place a platform with a width not less than 1000 mm. It is irrational to make the passage width less than 1000 mm, and the clear passage height (to the beams and the top of the openings) less than 2200 mm. The size of the flight should be calculated taking into account the fact that large loads will also have to be lifted up the stairs.

The number of ascents is usually made no more than 18 and odd: a person begins the ascent and enters the floor with the same foot.

Differences in the height of steps of more than 5 mm throughout one flight are strictly not allowed. Together with the Ministry of Emergency Situations, which is fighting to reduce the number of accidents, doctors are in favor of this strict requirement: such unevenness in movement leads to sharp point loads on internal organs, in particular on the kidneys.

The height of the handrails is about 900 mm; if the width of the passage allows, for a flight located near the wall, handrails should be made on both sides to increase safety when descending.

Children are treated specially: a gate is provided to prevent very young children from entering the stairs, and the distance between the balusters of the fence is made no more than 100 mm. Sometimes they provide child handrail at a height of 450 mm.

If, according to calculations, the flight of stairs is located near a window opening, it is unacceptable to leave it without a reliable fence.

When choosing a design solution for a staircase, you should calculate the maximum load that it can withstand.