A beautiful house is, first of all, about correctly designed details. Coziness and comfort should be present in every corner of the space, which is why the creation of an interior should be approached thoroughly, thinking through every little detail.

The staircase in such a house must not only meet the requirements of building codes, but also be attractive. That is why stringers are given special attention in its design.

What does the building consist of?

Not everyone knows what a stringer is, because they do not assume that a staircase is a special structure consisting of several elements. Violation of interaction between them leads to a decrease in the level of security.

Supports play an important role in organizing the spans between the first and second floors. They are called stringers. The element is presented in the form of stair beams located on each flight, to which the steps are attached. When looking at the entire structure from the side, you can see their end.

The detail helps to create a special style and add originality to a simple staircase. Often this element is used in a design instead of a bowstring, but they have the same function. It is the stringers that help to visually reduce the staircase and make it not so large.

According to the standards, the element must withstand the weight of a person and even objects lifted to the second floor; there can be no talk of any vibrations. If, when lifting, you feel that the stringer is trembling or swaying, it means that a grave mistake was made during its construction.

The difference between an element and a bowstring

The bowstring looks very similar to the stringer, but the main difference is the installation method. The tread is formed from the inside, and such a connection is a tie on which the structure rests. The combs are not cut out, as in a stringer, but are selected, that is, milled.

Stringers differ from bowstrings in size. The shape depends on the type of future steps and the degree of load. These factors cannot be ignored as they play an important role. According to building codes, a weight of up to 250 kilograms per ladder is allowed.

Classification and types

Playing the role of support for the stairs, stringers duplicate the gaps and pitch of the structure. The elements are located parallel or at appropriate points; they are also called nests. If we consider the classification from the constructive side, then they can be:

• straight;
• broken;
• screw.

Straight lines have overlays for steps, broken ones have a turn of up to 90 degrees and a landing, that is, between the 1st and 2nd floors the staircase has two different halves.

Screw ones always have a spiral shape, the binding is carried out on a central axis, which is often a pillar. If the reinforcement is good, such a reference axis is conditional.

The landing is the space between the flights of stairs, which is a horizontal surface through which the distinction between the first and second half of the structure occurs. It is necessary because, thanks to it, the second flight of stairs can reach the point specified in the drawing, while maintaining not only the angle of inclination, but also the proportions. Often the base rests on two beams or is rigidly tied to the vertical.

The monocosour stands on one beam. It is permissible to install it to the center or ends of the treads, but in this case it is necessary to additionally secure the element to the wall. There are special requirements for the beam, which must be wear-resistant, so it is better to use a steel pipe. Such a staircase can only be erected with permission from the construction supervision authority.

Stringers can be divided into two large groups: stepped and with fillies. The latter are a triangular element attached to the beam. Treads are installed on them. The design is considered complex in execution, but the most reliable.

Wooden stringers have their own classification:

• straight;
• comb;
• rounded.

Straight ones are used in the construction of such marches; when constructing overhead steps, a comb is used, and rounded ones are ideal for stairs of the same shape.

Execution materials

There are several materials that can be used to create stringers without disturbing the construction technology.

Stringing ladders can be made of wood, which makes them better than string ladders because the weight is significantly reduced. It can be a log, timber or board. For a small stairwell, this option is preferable. In addition to wood, it is necessary to highlight several types of materials.

Metal

• profiled pipe;
• metal profile;
• I-beam

Polymers

• plastic containing wood fiber;
• metal-plastic.

Composite material

• wood-metal;
• metal-polymer.

Reinforced concrete

Low cost and reliability have made metal and wood the most popular when organizing stairs. Combined models are necessary when forming a complex structure, when the project cannot be called standard, and its external attractiveness does not cover the safety requirements. Steel structures are in particular demand due to their strength and reliability.

Massive reinforced concrete structures are formed during finishing work. They are heavy, so the base for them must be calculated at the stage of creating the project. Subsequently, it will be placed parallel to how the foundation is laid.

Design calculation

Before constructing a staircase, it is necessary to calculate the basic quantities and only then create a project. You definitely need to know:

• height of the stairs;
• width and height of openings;
• length, how much is the projection along the floor;
• height of risers;
• the depth of the treads;
• total number of steps.

The total height is determined from the floor of the first floor to the floor of the second. It should not be less than 2 meters.

The projection is defined as the dimensions of the allocated space for the staircase structure. There are no specific requirements for depth; this value is, as a rule, arbitrary and selected based on personal preferences, the main thing is that it is convenient for the user. Most often it is 25-30 cm.

It is worth paying special attention to the height of the steps, which should not be more than 22 cm. The lower this indicator, the less effort you need to put in to climb to the second floor. The total number of steps in the staircase design is determined taking into account the length of the stringer and the height of the riser.

If the height of the staircase is 250 cm, the length is 400 cm, and the tread depth is 28 cm, then the number of steps can be found by dividing the length of the structure by the depth. In this case, it turns out to be 14 pieces.

The height of the riser is found by dividing the height by the resulting number of steps.

The length of the supporting structure can be determined using the Pythagorean theorem, that is, we add the square of the height to the square of the length and get the length of the stringer.

The reliability of the stringer depends largely on correctly selected beams when it comes to wood. Only hardwood will provide the necessary strength. The workpieces must be sanded. Perfect fit:

• maple.

The thickness of the supporting beam depends on the height of the stairs. One requirement applies here: the higher, the thicker.

The stepped stringer is installed quickly and easily; it is enough to make cutouts in the shape of a triangle. The result is a staircase projection.

The leg of the sawn triangle will be determined as the height of the riser and the depth of the tread. A ruler in the form of this geometric figure is necessary for marking the beam. According to the established marks, excess places are cut off with a circular saw.

Wooden stringers are used in most cases from the sides. The only disadvantage can be considered cutting, since it reduces the thickness of the supporting beam, which negatively affects the strength of the frame as a whole.

A straight/broken stringer should have a slope of 30-45 degrees, the height of the steps should be from 15 to 24 cm, and the treads, that is, the indentations from the supporting element on the base, should be 25-32 cm.

If the support is made of two or three beams, you should pay special attention to the ends of the supporting base of the stairs. They must not only be attached to other contacting elements, but also to each other. This connection creates a special force, thanks to which there is no loosening of individual parts during operation.

The number of beams in the support structure is not always the same. It is affected by the width of the steps. If the indicator is up to 1.2 meters, then one reinforcement is enough, if higher, but up to 1.5 m, then the staircase structure should be on a double base. Triple is necessary when the foot width is more than 1.5 meters.

In accordance with building codes, when the staircase is a bulky structure even with narrow steps, additional reinforcement will be needed. Additional fixation to the wall and ceiling is taken into account, especially in places of fractures.

The area of ​​contact of the elements on the sides and the height of the rise when calculating screw stringers as the main quantities are tied to the opening angle of the step. The reference length is inseparable from the rotation diameter of the structure. Markings are applied strictly in the horizontal plane from points located in the center and only along the center line.

Manufacturing

Stair support beams are produced in a wide variety. You can make a constructive solution yourself or see what experts offer. As an option, you can cut out the winder steps. Ultimately, the option chosen depends on personal preference and capabilities.

Before making a final decision, it is important to determine whether the staircase will fit in the opening provided for it, only then can installation begin. To do this, you need to draw a line for the second floor on the already calculated value of the flight of stairs. It is at this moment that it becomes clear that the chosen type of staircase cannot be installed, and it is necessary to resort to changes in the project.

During operation of the structure, you can easily get a head injury if the proper distance to the floor of the second floor is not ensured. At full height, a person reaches his level already standing on the third step. The distance from the head to the ceiling of the 2nd floor should not be less than 20 centimeters.

On metal beams: methods of fastening steps

Options for using metal beams require different types of fastening. If this is a collapsible structure, then a “glass” is used when a pipe is welded onto the stringer, and a supporting element having an axis equal to the inner diameter of the pipe is attached to the step.

High-quality fixation is ensured by the use of bolts. This will allow you to set the required rotation for the step and its height. Unfortunately, the method has one significant drawback - rapid wear during operation. In this case, rigid fixation benefits in durability.

Fastening can be done in a groove. If this is a non-removable structure, then greater stability is achieved due to the fact that the joints are adjusted at an angle of 45 degrees. The elements are connected to each other by welding.

From wood: sequence

The best option for making a wooden flight of stairs is a 2- or 3-support structure. Markings are made on a board or block, according to which trimming is subsequently done.

To ensure that the grooves match exactly, you can attach the blanks to each other, then refine the imperfections along the entire length. There is another option for leveling the support. To do this, overlay elements are prepared, which, after marking, are installed on the beam and checked for compliance with this type of assembly.

On concrete: varieties

Formwork is the basis of this type of stairs. It must be made waterproof so that the concrete mixture remains inside the created wooden frame and does not flow out of it. Reinforcement is placed inside, connected to each other in the form of a mesh, and only concrete is poured onto it.

To avoid voids, it is worth compacting the cement. For this, a special tool is used, or all the work is done manually. Only after complete hardening can you begin decorative finishing. Staircases are manufactured in accordance with GOST.

Design examples

The staircase must fit into the created interior of the house, since it sometimes acts as a separate element, receiving all the attention. Decorating steps and railings is sometimes more expensive than creating the structure as a whole.

• As a basic example, we can recall the classics with numerous decorative elements. These are always challenging design projects, especially when it comes to wood. Carvings and figured elements fit perfectly into almost any interior; they often turn out to be the main decoration in themselves.
• For those who prefer comfort and simplicity, it is worth considering the country style in which the staircase can be made. The steps can be made of ceramics or natural stone; artificial aging looks very good. Floral motifs and household items are used as the main decoration.

• If you like modern minimalism in design, then high-tech style is what you were looking for. It is dominated by a lot of glass, metal and the simplest forms, clear straight lines. Spiral and flight staircase structures look great in this design. Glass can be used in railings, steps or design elements.

The choice of material must begin even before work on the construction of the structure begins. It is worth taking into account the features, individual characteristics, purpose of the stairs and the age of the residents of the house. Where there are children, special safety requirements are imposed on the design.

Today there are no limits to human imagination; you just need to understand what exactly you want to see in the end. The unusual shape attracts more and more, sophistication does not lose popularity, but the business style is gaining more attention.

The advantage of a staircase on a stringer is that it is clearly visible. In addition to the functional component, such an element began to increasingly carry a decorative load in the overall interior. It has become popular to attach each step to a separate element, which is located on the support beam. In this case, if you lay two stringers, you can do without risers. The wooden steps are fastened using self-tapping screws, completely unnoticeably and very reliably. If a defect appears over time, then only one structural element requires replacement, and restoration becomes less expensive.

Metal stringers eliminate squeaking when moving. This is because the frame is rigid and durable; it is based on a welded rod. Even with high humidity, the metal does not deform, and the frame does not become loose over the years.

The cost of such a staircase is not much different from a wooden one, but increased strength can be achieved. You can use thin boards, since the steps do not experience a load-bearing load, and therefore can easily withstand the required weight.

To learn how to build a staircase for a terrace on stringers, see the video below.

Rice. 1 General drawing of the stairs

• Y - opening height - usually determined by the height of the floors of your house
• X - length of the opening - depends on how much space you can allocate in your house for the stairs
• Z - width of the stairs - depends on how much space you can allocate in your home for the stairs
• C - number of steps - in how many steps will it be most comfortable for you to move from floor to floor
• W - thickness of steps - geometric parameter of the material (for example, boards) from which you plan to build the stairs
• F - step protrusion - the distance by which the upper step will hang over the lower one
• T - thickness of the stringer - a geometric parameter of the material (for example, boards) from which you plan to build the staircase

"Show risers: H" function

Rice. 2 Execution of stairs with risers

You can build your staircase with or without risers. This function allows you to see what the design will look like with both options.

Function “Upper step below the floor of the 2nd floor: SP”

Rice. 3 Execution of the staircase, with the top step below the floor of the 2nd floor

Depending on the relative placement of the structure and the floor of the upper floor:

1. The upper plane of the top step is flush with the plane of the floor of the upper floor;
2. The upper plane of the top step is lower than the plane of the floor of the upper floor by the height of the step.

The choice of one or another mutual placement may depend on: the thickness of the interfloor ceilings, the desired relationship between the number of steps and their height, the length of blanks for stringers and the length of the opening, the desired angle of inclination of the stairs, or simply the tastes and preferences of the owner of the house. Please note that in the figure in which the upper step is below the floor of the 2nd floor, the thickness of the interfloor ceiling is greater than in the figure in which the upper step is at the floor level of the 2nd floor. If the thickness of the ceiling is less than the height of the step, the stringer simply will not rest against the ceiling (therefore, when demonstrating the second option, this thickness had to be increased).

Black and white drawing function:

Rice. 4 Black and white drawing of a staircase

It is advisable to use this function in two cases:

1. If you are used to working with standard GOST drawings, and, accordingly, better perceive graphics without color content.
2. If you are going to print the results of the calculator. Then you will spend less paint/toner and the visual perception of the drawings on paper will be better. And, of course, this function is used when printing on a black and white printer.

Function "Change lifting direction: LR"

Rice. 5 Type of stairs with different directions of ascent

A specific staircase, which is placed in a certain way in the house, can be approached from the side from two sides or only from one side - when the staircase is in contact with the wall. In the latter case, there are two options for placing the structure relative to the observer:

1. Rise from left to right;
2. Ascent from right to left.

This function allows you to visualize both of these options.

Calculation of a straight staircase with stringers

The main result of this calculator:

1. Drawing of a stringer
2. Step drawing

Based on these drawings, the parts from which the structure is assembled are made.

Rice. 6 Drawings of stringers and steps

All other drawings show the final appearance of the structure: after joining the stringers and steps with each other.

A special feature of this calculator is the implementation of two functions:

1. Assessing the convenience of the stairs;
2. Adjustment of staircase design.

Assessing the convenience of a staircase is carried out according to three criteria:

1. Compliance of the design with the average stride length. According to this criterion, the sum of the step depth and the two heights should equal the average step length. The average human step length is 63 cm.
2. Step depth. Comfortable step depth is from 28 cm. For a given opening length, the step depth can be adjusted by changing the protrusion.
3. The angle of inclination of the stairs. The optimal angle of inclination of the stairs is from 30° to 40°. At tilt angles from 20° to 30° and from 40° to 45°, the comfort level of movement between floors is significantly reduced. Angles of inclination beyond the above limits can significantly affect the speed of movement between floors and the safety level of the stairs.

Based on the results of assessing a specific design, an indicator of the level of convenience is given for each of the criteria, and the staircase is assigned an overall level of convenience. Online calculation of a straight staircase on stringers allows you to assess whether the staircase meets the well-known criteria for convenience, but you must always remember that your staircase in your home should serve your purposes as effectively as possible. And if, in accordance with these goals, you need to build the most non-standard staircase in the world - go for it.

If there is a need to improve the design of the stairs, the calculator gives advice on how to do this:

1. Reduce/increase the number of steps;
2. Increase the protrusion of the steps (if the depth of the steps is insufficient for comfortable walking);
3. Reduce/increase the length of the opening.

After adjusting the design, the normalized parameters will become closer to the ideal, but it is possible that such adjustments will have to be made several more times.

Instructions for the staircase calculator

In order to calculate a staircase using a flat staircase calculator on stringers, you need to know the height of the floor, the size of the space that you can allocate for the staircase, the materials with which you are going to build it, and, of course, the purpose of its use.

Before you start work, you need to carefully consider all the nuances: whether the staircase is adjacent to the wall, or in contact with elements of the interior of the house, and how this should affect the structure itself and the process of its construction. Perhaps, to choose the right option in terms of size and design, you will have to use a calculator to calculate and compare several. Before you start processing the material, make sure that the detail drawings correspond to the ladder that is suitable for you and your purposes. When building, attach the parts to each other, and the staircase itself to the house so that you can guarantee the reliability and strength of the structure for decades.

The stairs presented on our website can be divided into categories according to three mutually dependent criteria:

1. Length dimensions

A. Maximum length - all steps are placed on one pair of bowstrings/stringers;

b. Medium length - steps are placed on two pairs of strings;

V. Minimum length - the steps are placed on three pairs of strings, the length dimension is regulated by changing the number of steps on the corresponding pairs of strings;

2. Width dimensions

A. Maximum width - steps are placed on two or three pairs of strings, the width dimension is regulated by changing the number of steps on the corresponding pair of strings;

b. Average width - the steps are placed on two parallel pairs of strings, the width dimension is equal to two widths of the stairs;

V. Minimum width - all steps are placed on one pair of bowstrings/stringers, the width dimension is equal to the width of the staircase;

3. Difficulty in manufacturing

A. Easy to manufacture - made from bowstrings/stringers and rectangular steps;

b. Medium complexity of manufacturing - made from bowstrings, rectangular steps and platforms;

V. Difficult to manufacture - made from bowstrings/stringers, rectangular steps, platforms and turning steps.

Stairs presented on our website:

• - 1.a.-2.v.-3.a.
• - 1.b.-2.a.-3.b.
• - 1.b.-2.b.-3.b.
• - 1.b.-2.b.-3.c.
• - 1.c.-2.a.-3.b.
• — 1.v.-2.a.-3.v.
• - out of classification
• Straight staircase on stringers - 1.a.-2.v.-3.a.

In each specific situation, the floor height is already specified. Based on your own preferences, you can choose the level of convenience: either the convenience criteria are met, or the staircase is flatter, or steeper, etc. Having this information, we can talk about the number of ascents (steps and platforms) in a particular situation.

Let's imagine that we have, for example, 12 ascents - steps and platforms. Staircase design is the shape of these risers (steps, turning steps, landings) and how these 12 risers are placed relative to each other.

You can place all these 12 rises in one row along the length of the opening - “”, “Straight staircase on stringers.” In this case, your stairs will have a maximum dimension in length, a minimum dimension in width and will not be difficult to manufacture.

These 12 lifts can be placed in 2 rows, rotated 90° relative to each other (when viewed from above). With a platform on the turn - "" - a simpler option to manufacture (for example, 5 steps on the lower pair of bowstrings, a platform and 6 steps on the upper pair of bowstrings). With rotary steps on the turn - "" - a more difficult option to manufacture (for example, 3 steps on the lower pair of bowstrings, 3 rotary steps and 6 steps on the upper pair of bowstrings). In these cases, your stairs will have an average dimension in length and an adjustable dimension in width.

You can place these 12 lifts in 2 parallel (when viewed from above) rows placed next to each other. With a platform on the turn - "" - a simpler option to manufacture (for example, 5 steps on the lower pair of bowstrings, a platform and 6 steps on the upper pair of bowstrings). With rotary steps on the turn - " " - a more difficult to manufacture option (for example, 3 steps on the lower pair of bowstrings, 3 rotary steps and 6 steps on the upper pair of bowstrings). In these cases, your stairs will have an average dimension in length and an average dimension in width.

You can place these 12 lifts on 3 rows perpendicular to each other (when viewed from above). With platforms on turns - "" - a simpler option to manufacture (for example, 2 steps on the lower pair of bowstrings, a platform, 3 steps on the middle pair of bowstrings, a platform and 5 steps on the upper pair of bowstrings). With turning steps at the turn - “Staircase with three flights and turning steps” - a more difficult option to manufacture (for example, 2 steps on the lower pair of strings, 3 turning steps, 2 steps on the middle pair of strings, 3 turning steps, 2 steps on the top a pair of bowstrings). In these cases, your stairs will have a minimum length dimension and an adjustable width dimension.

Or you can choose ““, which is not similar to any of the above and will give the interior of your home a truly sophisticated look.

This design is relevant in a situation where you want an easy-to-manufacture staircase, the length of which would depend on the height of movement (subject to the convenience criteria) and which would not take up much space in width.

A stringer in a staircase is an inclined metal beam on which the steps rest.

This calculation applies to metal stringers made from rolled channels.

Attention! In the article, the font periodically flies off, after which, instead of the sign for the angle of inclination of the stairs "alpha", the sign "?" is displayed. I apologize for the inconvenience.

Initial data.

The width of the flight of stairs is 1.05 m (prefabricated stair steps LS11, weight of 1 step is 105 kg). Number of stringers – 2. H = 1.65 m – half the height of the floor; l 1 = 3.7 m – stringer length. The angle of inclination of the stringer is α = 27°, cosα = 0.892.

Collection of loads.

As a result, the current standard load on the inclined stringer is equal to q 1 n = 449 kg/m 2, and the calculated load q 1 r = 584 kg/m 2.

Calculation (selection of the stringer section).

The first thing to do in this calculation is to bring the load per 1 sq. m of the march area to the horizontal and find the horizontal projection of the stringer. Those. essentially at the actual length of the stringer l 1 and load per 1 sq.m march q 1, we translate these values ​​into the horizontal plane through cosα so that the relationship between q and l remained in force.

For this we have two formulas:

1) the load per 1 m 2 of the horizontal projection of the march is equal to:

q = q 1 /cos 2 α;

2) the horizontal projection of the march is equal to:

l = l 1 cosα.

Please note that the steeper the angle of inclination of the stringer, the shorter the length of the flight projection, but the greater the load per 1 m 2 of this horizontal projection. This is precisely what preserves the relationship between q and l which we strive for.

As proof, consider two stringers of the same length 3 m with the same load 600 kg/m2, but the first is located at an angle of 60 degrees, and the second - 30. The figure shows that for these stringers the projections of the load and the length of the stringer are very different from each other, but the bending moment is the same for both cases.

Let us determine the standard and calculated value of q, as well as l for our example:

q n = q n 1 /cos 2 α = 449/0.892 2 = 564 kg/m 2 = 0.0564 kg/cm 2 ;

q р = q р 1 /cos 2 α = 584/0.892 2 = 734 kg/m 2 = 0.0734 kg/cm 2 ;

l = l 1 cosα = 3.7*0.892 = 3.3 m.

In order to select the cross section of the stringer, it is necessary to determine its moment of resistance W and moment of inertia I.

We find the moment of resistance using the formula W = q р a l 2 /(2*8mR), where

q р = 0.0734 kg/cm 2 ;

l= 3.3 m = 330 cm – length of the horizontal projection of the stringer;

m = 0.9 – coefficient of operating conditions of the stringer;

R = 2100 kg/cm 2 – design resistance of steel grade St3;

8 – part of the well-known formula for determining the bending moment (M = ql 2 /8).

So, W = 0.0734*105*330 2 /(2*8*0.9*2100) = 27.8 cm 3.

We find the moment of inertia using the formula I = 150*5*aq n l 3 /(384*2Ecos?) , where

E = 2,100,000 kg/cm 2 – elastic modulus of steel;

150 – from the condition of maximum deflection f = l/150;

a = 1.05 m = 105 cm – march width;

2 – number of stringers in a march;

5/348 is a dimensionless coefficient.

For those who want to understand in more detail the determination of the moment of inertia, let us turn to Linovich and derive the above formula (it differs slightly from the original source, but the result of the calculations will be the same).

The moment of inertia can be determined from the formula for the permissible relative deflection of the element. The deflection of the stringer is calculated by the formula: f = 5q l 4 /348EI, from where I = 5q l 4/348Ef.

In our case:

q = aq n 1 /2 = aq n cos 2 ?/2 – distributed load on the stringer from half the march (in the comments they often ask why the kosour is considered to cover the entire load of the march, and not half - so, the two in this formula exactly gives half the load);

l 4 = l 1 4 = (l/cos?) 4 = l 4/cos? 4 ;

f = l 1 /150 = l/150cos? – relative deflection (according to DSTU “Deflections and displacements” for a span of 3 m).

If we plug everything into the formula, we get:

I = 150*cos?*5aq n cos 2 ? l 4 /(348*2E l cos 4?) = 150*5*aq n l 3 /(348*2Ecos?).

Linovich has essentially the same thing, only all the numbers in the formula are reduced to the “coefficient With depending on the deflection." But since in modern standards the requirements for deflections are stricter (we need to limit ourselves to 1/150 instead of 1/200), then for ease of understanding all numbers are left in the formula, without any abbreviations.

So, I = 150*5*105*0.0564*330 3 /(384*2*2100000*0.892) = 110.9 cm 4.

We select a rolling element from the table below. Channel No. 10 suits us.

This calculation was carried out according to the recommendations of the book by L.E. Linovich. “Calculation and design of parts of civil buildings” and provides only the selection of the cross-section of a metal element. For those who want to understand in more detail the calculation of a metal stringer, as well as the design of staircase elements, you need to refer to the following regulatory documents:

SNiP III-18-75 “Metal structures”;

DBN V.2.6-163:2010 “Steel structures”.

In addition to calculating the stringer using the above formulas, you also need to do a calculation for instability. What it is? The stringer may be strong and reliable, but when walking up the stairs it feels like it is shaking with every step. The feeling is not pleasant, so the standards provide for the following condition: if the stringer is loaded with a concentrated load of 100 kg in the middle of the span, it should bend no more than 0.7 mm (see DSTU B.V.1.2-3:2006, table 1, paragraph 4).

The table below shows the results of calculations for instability for a staircase with steps 300x150(h), this is the most convenient size of steps for a person, at different floor heights, and therefore different stringer lengths. As a result, even if the above calculation gives a smaller cross-section of the element, you need to finally select the stringer by checking the data in the table.

March projection length Lx, m	March height N, m	Stringer length L, m	Rolled channel number GOST 8240-97, DSTU 3436-96	Number of bent channel GOST 8278-83	I-beam number GOST 8239-89	Dimensions of bent square pipe GOST 30245-94, DSTU B.V.2-6-8-95

In order to correctly design a staircase, you can use standard series:

1.450-1 “Stairs made of prefabricated reinforced concrete steps on steel stringers”;

1.450-3 "Steel stairs, platforms, stepladders and fences."

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Stairs on stringers can be made with your own hands. When designing and constructing a building higher than one floor, one cannot help but think about the construction of a staircase. The most common staircase structures are:

• on stringers;
• on bowstrings;
• on pain;
• screw.

But we can safely say that the most common and in demand are stringer stairs. Their advantages include:

• use of a wide range of materials;
• ease of manufacture and installation;
• when the width and height are specified, they can be easily adapted to the required dimensions;
• simple fastening of steps, if necessary they are easy to replace;
• the ability to place stringers closer or further from the edges of the steps;
• decent appearance that is easy to stylize if desired.

Design Features

Stringers are supporting parts of the stairs that are installed at a certain angle and steps are attached to them. In another way they are called beams. Depending on the width of the staircase structure being built, as well as the materials for manufacturing, its structure may contain one or more such elements.

How to make a stringer for stairs? Having the necessary information and the necessary materials, you can make such a design yourself.

What materials are used? Various materials are used to create staircase structures. To make a stringer, the following are most often used:

• wood;
• rolled metal;
• reinforced concrete.

Among all, the easiest material to process for staircases on stringers is wood.

Its characteristics, such as a high level of mechanical strength, low specific gravity and attractive appearance, add to its advantages. The wooden structure lends itself well to grinding and polishing, and with the production of modern protective equipment it is perfectly protected from moisture and other adverse influences.

A wooden staircase on two stringers is a classic option that fits into almost any interior. Making a wooden staircase is so simple that it can easily be done at home. This does not require special tools; everything you need can easily be found in your home workshop.

A more difficult material to process, but no less used, is metal. To construct a metal stringer, types of rolled products such as an I-beam, channel or rectangular pipe are often used. Almost always, when a structure is made on one stringer, it is made of metal. However, the more common option is to use two beams.

The metal structure is strong, reliable and allows you to make curved variations of stairs, which is an indisputable advantage of the material. However, making a curved stringer at home will not be possible. You can try to make a straight, more traditional stringer with your own hands if you have the skills to work with metal, a grinder and a welding machine.

Regarding reinforced concrete, it is often used in mass housing construction. Typically, such stairs are cast in a factory as a ready-made monolith. In this case, the beams and steps are inseparable from each other. But some factories produce separately manufactured beams and steps. This design is assembled on site in parts using metal pins and mortar. It will be problematic to assemble a reinforced concrete structure on stringers with your own hands without the help of a crane.

Calculation of the dimensions of the structure

1. Structure height. The distance from the floor on which the structure is mounted to the floor of the next floor is measured vertically (including floors).
2. Total horizontal length of the structure. The distance that the ladder will occupy from the first to the last step.
3. Tread depth. The distance allotted for placing your foot when climbing stairs. Often it is taken in the interval of 25-40 cm; this distance is considered ergonomic and safe when using the stairs.
4. Riser height. A riser measuring 12-22 cm will be convenient. Lower - the steps will be too small; higher - you will have to raise your leg too high; in both cases, using the stairs may not be very convenient.

Calculation example.

Let's say the height is 3 m;

Desired length 4.5 m;

For example, let’s take the depth of the tread to be 30 cm (0.3 m).

Let's calculate the number of steps: divide the length of the stairs by the depth of the tread and get the required number.
4.5 m / 0.3 m = 15 pieces.

Let's calculate the height of the riser for this design: divide the height of the stairs by the number of steps calculated above and find the required height:

3 m / 15 pcs. = 0.2 m (or 20 cm).

This size is included in the generally accepted range and is convenient for using the stairs.

To calculate the length of the stringer, imagine that the entire structure is a triangle. The role of the legs is played by the length and height of the staircase, and the beam is its hypotenuse. Knowing two sizes, using the Pythagorean theorem, we find the third.

Video about making a simple staircase using a cut stringer and calculating the stringer:

Calculation example.

The squared height plus the squared length equals the squared length of the stringer. We take the square root of the resulting number and find the length of the beam for our stairs.
32 + 4.52 = 9 + 20.25 = e29.25 = 5.4 m.

It turns out that for a staircase with such dimensions you will need a beam 5.4 m long. Having done these simple calculations correctly, you can make a stringer with your own hands and build a staircase at home yourself.

However, do not forget about such an important point as the fragility of the stringer. It determines the strength and resistance to constant and variable loads on the beams and stairs as a whole. Calculations for instability can be made by knowing what materials will be used for beams, steps, railings and finishing. It is very important to do this calculation correctly. Otherwise, the structure may sag or be destroyed.

Manufacturing of the product

How to make a stringer for a wooden staircase? A simple wooden staircase on stringers can be made quite quickly on your own. Often the most ordinary wooden structure for a cottage consists of such elements as:

• two beams;
• steps;
• risers;
• railing

For such a staircase on stringers, you can purchase ready-made steps and railings, but the beams can be made by yourself. In addition to the material, you will need the following tools:

• saw;
• hammer;
• screwdriver;
• drill;
• Sander;
• roulette;
• level;
• dowels, screws;
• pencil and square.

Video about making a spiral staircase on a stringer:

To make beams, you need to stock up on boards at least 6 cm thick and 25-30 cm wide. In addition to the size, you should pay attention to the quality of the wood. Most often they use oak, maple, pine or beech, carefully checking the boards for cracks and other damage that could reduce the strength of the structure. Finding quality material may not be easy, so you can use glued boards.

Video about making a staircase using a broken stringer:

Having selected the boards, they need to be marked according to the calculations made in advance. Using a corner, we mark with a pencil the places where the cuts will be made for the steps. At the ends we mark the places where there will be grooves for the transverse board, which is attached to both beams. Its length is usually equal to the width of the stairs. We make the second stringer for the stairs in the same way.

When all the steps are marked, use a saw to make the necessary cuts in the board strictly according to the pencil. The lower end of the beam, which will be fixed to the floor, is cut parallel to the places where the steps are attached. The upper part of the beams is cut at the desired angle depending on the method of fastening the structure. After all the necessary cuts have been made, you need to sand the finished beams. Now all that remains is to fasten all the parts (beams, steps, railings, risers) into place, and the staircase on the stringers will be ready.

Construction of a staircase in a private house is a very interesting process. With the help of a staircase, you can set the theme of the entire future interior of the house.

The appearance of the future staircase depends on many factors, including the choice of the load-bearing structural element. One of the most common and versatile options is a kosour. To understand what a stringer is, we advise you to read this article.

What is a kosour?

Any staircase consists of two main parts - a supporting element and steps. One of the options for the load-bearing element of stairs is a stringer.

Stringers for stairs may vary:

• according to the shape of the structure;
• number of load-bearing elements;
• manufacturing material.

Varieties of stringer designs

According to the shape of the stringers, they are divided into:

• straight;
• turning;
• screw.

The most common are straight stringers, which are used for the construction of simple stairs.

Rotary stringers are used in stairs consisting of several flights.

For spiral and rounded staircases, a spiral stringer is used.

Also, stair stringers are divided according to the number of guides and their location:

• on 2 side stringers;

• on 1 stringer, with a central location.

Depending on the width of the march, it is possible to use three or more stringers to strengthen the structure.

Parameters and sizes

In order for a straight staircase on stringers to be comfortable and safe, it is important to correctly calculate the parameters of the load-bearing element.

Parameters that need to be calculated:

• Length of the stringer. To calculate this parameter, you need to remember school mathematics, namely the Pythagorean theorem:

A 2 = B 2 + C 2.

• . This parameter is important for determining the size of the parts to be cut.

• Stringer size. This refers to the size of the board from which the stringer will be made. The thickness of the board must be at least 8 mm, and the width is determined depending on the size of the steps. The calculation is carried out in such a way that the cut is no more than half the entire width.

Wooden stringer

There are two options for making stringers:

• Toothed (stepped)- made by cutting out sections for steps from a solid board.

For correct marking, you need to prepare a template - measure the size of the tread and riser on the board and screw the rail at an angle equal to .

A template needs to be prepared so that the size of all steps is the same, and the stairs on stringers are easy to use.

• Filly - installation is a little more complicated due to the need to manufacture more parts of the same size.

Stringer on fillies is a more complex design, but it is considered more reliable.

Metal stringer

A metal stringer is considered more durable and reliable than a wooden one. There are also a number of ways to make it:

• Tape - performed by cutting out elements from a whole sheet of metal. Depending on the size, it is possible to cut out the stringer entirely or partially, followed by welding. Welding seams are processed and painted in such a way that the feeling of a solid string is created.

• Stringer made of profile pipe. It is made by cutting the required number of pieces equal to the width of the tread and the height of the riser, after which they are welded at an angle of 90°.

• Kerchiefs are an analogue of fillies. Made from corners welded at right angles.

The second option for installing metal fillets is to weld a protrusion to an inclined load-bearing element at the angle necessary to place the platform.

Video on installing a metal stringer:

Concrete and reinforced concrete stringer

Concrete stairs are the most reliable and durable, it’s not for nothing that they are widely used in the construction of multi-apartment, industrial and commercial buildings.

Concrete stringers also come in different types:

• Standard - with the help of which many objects, both private and public, were built.

Making this kind of stringer is permissible both with your own hands and in specialized factories.

• Individual - this type of stringer is made based on a developed design project; the product can have almost any shape. The possibility of manufacturing will depend only on the skills and experience of the craftsman performing the work.

Including on the stringer, it is carried out according to the standard algorithm:

1. Preparing the foundation.
2. Assembly of durable formwork.
3. Knitting of a reinforced frame.
4. Pouring concrete.
5. Processing and finishing after the structure has hardened.