Online calculator for stairs with turning steps. Detailed calculation of stairs with winder steps

The design of a staircase with winder steps is in great demand in houses where comfortable, safe movement between floors is required, but there is no technical possibility of placing a straight structure. Such structures require special attention at the stage.

Diagram with the names of the winder staircase elements

Winder steps are widely used for the following types of stairs:

1. Screw. The most compact options lifting structures. The recommended width of the total opening is up to 3000 mm.
2. L-shaped. Devices with 90˚ rotation. Occupy less space than straight marches or marches with platforms.
3. U-shaped. They have a 180˚ rotation and are more compact than the previous version.
4. Curvilinear. Features smooth turning lines. Winder steps (treads) are more often used with the same parameters, which creates additional comfort when climbing.

The shape of the turning tread in such structures has the shape of a truncated triangle. Due to the compactness of the device, it saves.

Winder steps can be located at the bottom, top, in the middle flight of stairs. For safe movement, the first two options are recommended. They have good visibility of the turning area, which allows you to orient yourself in time and change the position of the foot or the length of the step.

Schemes of winder stairs are more difficult to complete than straight structures or with platforms for transition. Therefore, there are often drawings with incorrectly executed structures.

This not only reduces the comfort of movement, but also increases the risk of injury from a fall.

Basic requirements for winder stairs

Comfort and safety are the basic principles that any building structure must meet. The staircase is no exception. A number of the presented technical requirements are also typical for straight march structures:

All of the listed characteristics and data will ensure comfort and safety of movement between floors.

Advantages of winder designs

The main advantages of a winder staircase include:

1. Compactness. Often the area or dimensions of the opening to the second floor do not allow the placement of a straight structure. In order to overcome these difficulties with minimal losses, they install winder steps in turning marches.
2. Aesthetics. adds a special charm to the interior of the house.
3. Saving materials. As the slope angle (steepness) increases, the consumption of materials decreases slightly.

The disadvantages include a decrease in the level of comfort and safety of movement. The winder treads differ in size, you will have to adapt. And it is more difficult to disperse on such a flight than on ordinary stairs.

Technical data for drawings

To correctly draw up a diagram of a winder staircase, it is necessary to take into account all the standards listed above, the dimensions of the premises and link them to the plan. To do this, proceed to the following steps:

1. Determine the location of the structure.
2. Make the appropriate measurements: the width of the opening, the height from the finished floor of the first floor to the surface of the floor of the second.
3. Draw to scale with detail. If there are openings, windows, ledges, niches in the place where the stairs will be mounted, they are marked on the drawing with reference to the walls and floor.
4. Select the type of structure and building material for it.
5. Make preliminary calculations on the number, height and depth of steps.

This data will help you make the right choice of design that will ensure compliance with building codes.

Preliminary data calculation

Knowing the height between levels and the formula for comfortable movement, you can calculate the length of the flight of stairs and the number of expected steps. For example, the specified height between floors is 2600 mm. We will select the height of the degrees from the recommended range of 120 mm. Let's make all the calculations to build the drawing:

The example shows that it is better to reconsider the parameters of the steps. This will significantly save space. For example, with a riser height of 150 mm, the tread depth will become 300 mm, and the length of the staircase will be 5,400. This will save 3 sq. m. usable area of ​​the house.

Drawings and methods for calculating winder steps

Taking into account modern realities and get a quick result, you can use several ways to draw up a design diagram.

Project programs

The best option for design. There are software that, based on the drawing, issue specifications for materials with cutting. There is no provision for this option. But after completing a detailed drawing, it will not be difficult to calculate the amount of material. The disadvantage of this method is the time spent searching and mastering the software product.

Ready solutions

Drawings posted on the Internet allow you to select suitable option. But you should check them for compliance technical requirements, to protect yourself from someone’s design illiteracy.

To do this, you can use online calculators or master one of the methods for calculating winder steps.

The main difficulty when working with such drawings is to fit them into the required space ready-made solution. You may find that a window or a ledge on the wall ends up in the place where the stairs are installed.

You will have to either adapt the design to fit, or look for another suitable option.

Online calculators

They will help you make calculations and give recommendations for correcting the design if it does not comply building regulations. Based on the received data, a detailed drawing is automatically generated. This is the simplest and affordable way development of drawings for custom sizes. But in the future you should link to .

Otherwise, the resulting structure may close the window or doorway.

Proportion method

The main difficulty in independently designing a staircase with winder steps is calculating the number and developing the shapes of the rotating elements. Calculation using proportions. This method is suitable for stairs with a rotation of 90˚, 180˚. First, you should draw a top view of the future structure, fitting it into the intended area. Next, perform a series of operations:

This is the simplest and most accessible way to construct a drawing. There are three other methods: Danish, sweep and line lifting. The listed technologies are complex and require deeper knowledge of mathematical analysis. These methods require taking into account the horizontal and vertical curvature of the structure.

It should be noted that the drawing using any of the above methods is performed with a certain degree of error. Therefore, even professionals adjust parts at the assembly site. A winder staircase is a more complex design, so if you are not confident in your abilities, then it is better to entrust the calculation, design, and installation to specialized enterprises.

It often happens that insufficient space in a private house simply does not allow the construction of an ordinary single-flight staircase to the second floor. We have to look for another solution - divide the rise into two flights or fit a screw structure into the available space.

Or you can combine these approaches - the staircase will have two flights, but between them there is not a platform, but a section of ascent of the spiral type, for the transition between straight sections. In this area, so-called winder steps are installed, which allow you to change the direction of the stairs. The design, of course, becomes more complicated, but the required compactness of the interfloor transition is achieved.

Can a winder staircase be built with your own hands? Yes, definitely. But in order to understand this issue, it is necessary to first consider what types of structures that have winder steps are, and learn how to calculate them.

Stairs with winder steps

First of all, it must be said that winders are steps that have the shape of a regular or irregular triangle and are almost always located on the same support. Such steps can completely form the structure of the staircase or replace the platform between two flights.

Staircases with winder steps include several types of structures:

Many private houses, apartments, offices have unusual layout, or limited space for placing the staircase, which makes it difficult and narrows the choice of its type - standard straight stairs or rotary ones with landings may simply not fit.

For comfort, a staircase with winder steps was invented, which can be easily adjusted to any layout features and building sizes. It saves usable space and looks very elegant if you follow everything construction requirements according to the width of the steps, then such a staircase with turning steps is also not dangerous.

Features of the winder staircase

A well-made staircase can serve as both a practical solution and a unique element of the interior. An L-shaped staircase with winder steps is made of natural wood or high-strength aluminum material. In addition, it has a unique shape and compactness, which makes it indispensable in private homes and other facilities.

A properly designed ladder can withstand significant loads and has a long service life. Our service website invites you to carry out a high-quality calculation of a staircase with winder steps, taking into account the specific characteristics of your house, apartment, or other object.

What are the features of the calculator?

From the site you will make a full calculation of a staircase with winder steps at 90 degrees. In addition, it is automatically generated 3D model using the obtained calculations. The three-dimensional model reflects the convenience/inconvenience of passage, allowing you to evaluate possible risks. As a result, you receive ready-made engineering drawings for your own production.

With us you save money. The calculator for calculating stairs with winder steps will make accurate calculations of the volume, number of steps, dimensions and construction materials. You don’t have to call a craftsman and pay extra for his services, or contact a furniture company and order the manufacture of a staircase.

Save time. Why would you waste time on complicated calculations when you have our staircase calculator? You will be required to enter the dimensions and click the “Calculate” button. You no longer need to waste energy on doing everything yourself, or use other programs and suffer trying to save calculations - with us you can send or save all the necessary files in one click.

How to make calculations?

First of all, measure the height of the opening for the stairs on the stringers - between the floor of the 1st and 2nd floors. Everything is extremely simple. Enter the units of measurement - cm, m. Then select the color in which the drawing will be generated (color is convenient for viewing, black and white for printing).

After which you need to enter the coordinate points of the flight: height, length, width of the stairs, number of steps, indicate their parameters (thickness, protrusion). Then click on the “Calculate” button.

As a result, you will receive calculated data on necessary materials, according to the elements of the staircase: stringers, steps, risers, drawing of a staircase with winder steps. By clicking on the “View in 3D” button, you can view a three-dimensional 3D model of the winder staircase design.

Thanks to the calculator you will get both accurate general values stringers, and each individually. Namely, the width was recorded both horizontally and vertically, and the angle of inclination. In addition, you are provided with data on the optimal volume and parameters of materials: width, length, thickness, quantity and volume, so that the rotary staircase with winder steps will best meet your and construction requirements.

What will you get? Detailed drawings, 3D model, calculation of the design of a staircase with turning steps

You get a practical solution for making accurate calculations for stairs with turning steps. In addition, with the help of our calculators you can independently design and calculate other types of stairs, Various types roofs In the near future it will be possible to calculate other necessary structural elements of the house - the foundation, walls, and more. Subscribe to news in our groups in in social networks to be aware of the release of a new functional calculator.

Using the site is very simple - you do not need any special knowledge, you just need to enter a couple of values, and you can get a professional design for a staircase with winder steps, as well as a calculation for another type of staircase or roof completely free of charge!

When planning to make a wooden or metal staircase with your own hands, you need to pay a lot of attention to calculations. Despite its apparent simplicity, the staircase is a very complex engineering structure, each node of which must be thought out, and all together they must create a single ensemble.

The design of a metal/wooden staircase must take into account its functional and decorative components. This will be more difficult to do, the less experience you have in this type of work. Since we don’t do calculations every day, we need to describe in detail how to calculate the stairs to the second floor of a private house. General principles wooden and metal stairs they do not differ. As they say, “the devil is in the details.” We will consider them in detail.

It is worth noting that the arrangement of stairs in apartment buildings or administrative buildings is regulated by many documents. The main ones are GOST 23120-78 Flight stairs, platforms and steel fences and SNiP IV-14-84 Collection 1-14 Stairs.

However, in private houses, the height of which is often limited to two floors, the owner is free to choose the configuration. Although, of course, the basic rules for constructing stairs must be followed.

Rule 1 - Choosing the location of the stairs in the house

Making a straight staircase in accordance with the standards in a private house is hampered by limited space. Therefore, many owners give preference complex structures: flight staircase with a turn or spiral. Professionals put forward several recommendations regarding where and how to place the staircase in the house so that it takes up little space.

• It is better to place the stairs in the part of the house that is least used. The staircase in the living room creates certain inconveniences;

• provide free access to the stairs;

• landings are preferable to winder steps. Especially if independent construction is planned;

• consider more first simple options, and only then more complex ones;

• Keep in mind that you will need to not only walk up the stairs, but also bring in/take out furniture and equipment. It should be easy to use for all family members;

• if you plan to use the space (place) under the stairs in the house, it is better to choose a closed structure. And vice versa, open staircase makes the space more spacious, so it is advisable to use it in rooms;

• Please note that installing a metal staircase in wooden house can be done after the house shrinks. That is, in 1-1.5 years. Otherwise, shrinkage of the house will lead to a violation of the integrity of the structure.

• make sure that you can make an opening in the ceiling (ceiling) for a staircase to provide access to the attic or attic. For example, in monolithic slab the construction of a staircase creates significant difficulties.

How to reduce the size of the opening for the stairs to the second floor?

Useful tips from experienced professionals:

• 20% is possible if a staircase with 180 degree winder steps is installed;

• Installing a staircase with two flights and a platform will help by 30%. Space saving is achieved due to the fact that the movement changes by 180°;

• by 60% by installing a staircase with steps " duck step»;

• 80% is achieved by installing a spiral staircase. IN in this case movement changes 360°.

Rule 2 - Shape and types of stairs

In a private house, it is possible not to strictly follow standards and GOSTs. However, the basic principles of staircase arrangement must be observed, since neglecting them may result in a decrease in the safety of this engineering structure.

Before you start making calculations, you need to know that there are two important factors that will affect the result.

Firstly, this is a design feature.

From a design point of view, all stairs can be divided into three types:

• marching. Consist of separate marches. They, in turn, are divided into single-flight, two or more - multi-flight. In addition, the flight of stairs can be straight, with a landing or with turns (winder steps).

In private houses, wooden and metal staircases with winder steps (with a rotation of 90, 180, 360 degrees) are popular.

• screw (spiral). In stairs of this type, the steps are twisted around an axis. They are convenient when there is no free space in the room for a marching structure. But the construction of a spiral staircase is much more labor-intensive and requires more careful calculations.

• folding. They relate to portable structures, so we will skip them, since we will do the calculation for a stationary staircase.

Secondly, this is the shape of the frame.

The frame of a metal and wooden staircase can be made in three options:

• staircase on stringers. The basis of the frame is one or two solid beams, on which steps are laid on top.

• ladder on a bowstring. The frame consists of two support beams that support the steps from the sides

• staircase on rails(from German “pin”). The steps are fastened directly to the wall.

Rule 3 - Calculation of staircase parameters

Many users do not know what needs to be taken into account in order to calculate the stairs correctly. Professionals say that taking into account three main parameters will make the design safe, beautiful and easy to use.

The parameters of the stairs are shown in the figure

Stair height

Height - the distance from the floor of the first floor to the floor (not ceiling) of the second. Often the upper end of the staircase rests on the ceiling of the first floor. For ease of movement, there is a gap above such a staircase.

The distance from the step to the ceiling can be calculated as follows: take the height of the tallest family member and add 100 mm. Recommended clearance value ( working height stairs) - 2 m. This value must be constant throughout the entire flight.

Note. Place the ladder in living rooms This is only possible if the rooms on the first and second floors are heated. Otherwise, it should be placed in a non-residential area.

Stair length (flight length)

For a traditional flight design, the length of the staircase is equal to the length of the flight or the sum of the lengths of the flights plus the landing between them.

When calculating the length of a spiral staircase or a staircase with winder steps, the average length of the flight is calculated. In this case, the measurement is performed at a distance of 50 cm from the railing (edge ​​of the span).

Width of stairs in a private house

Width - the distance of the stairs from the wall or between two handrails. Recommended parameters are shown in the diagram.

Width of the flight of stairs:

• 1.5 m - increased level of comfort;

• 1-1.2 m - comfort zone;

• 0.8-1 m - only permissible for a flight of stairs located along the wall;

• less than 0.8 m. is only suitable for auxiliary stairs.

Width of a flight of stairs with winder steps:

Spiral staircase width:

• 1.4 m - comfort zone;

• 1.1 m is the minimum allowable width.

This is due to the fact that the winder steps taper towards the central element of the staircase.

Stair inclination angle (steepness)

The angle of inclination determines the ease of use of the stairs. Too much steep stairs allows you to save useful space, while the flat surface makes movement along it more comfortable.

The type of staircase depending on the steepness is shown in Fig. Here you can clearly see at what angle the staircase in a living room should be.

The most comfortable option for movement is in the green zone of the picture.

Material prepared for the website www.site

Note. When the angle of inclination is over 45°, you can only go down the stairs with your back forward.

As practice shows, most often in the house they use combined options. To understand at what angle to place the handrail on the stairs, you need to draw a parallel between the base of the stairs (stringer, bowstring) and lay the handrail along it. Mathematically, this is a simple calculation of the angle using the Pythagorean theorem.

Number of steps of the staircase

The number of steps is not regulated and depends on the height of the stairs and the height of the tread (riser). In two-flight staircases, it is recommended to have the same number of steps in both flights, but in practice the steps are distributed unequally between the flights.

Note. For multi-apartment residential buildings, the number of steps is regulated and is 9-11 steps.

Tread height (distance between stair steps)

Users found the distance between adjacent steps to be 150 mm most convenient for movement.

Note. For those who make their own stairs, the excess height can be easily removed by adjusting the height of the tread between the last and penultimate steps or between the first and second.

Stair step (step width)

You need to rest your full foot on the stair step. Therefore, the optimal width of the stairs should be at least 230 mm. (size 35). The minimum acceptable width is 100 mm. But frequent walking on such steps is fraught with injury.

Note. If you increase the width of the steps beyond 650 mm (the average step length of an adult), then when walking on such stairs you can get confused and stumble.

Note. When calculating the width of the stairs, do not forget that the distance between the balusters should be within 100-150 mm. Otherwise, such a fence will be unsafe. In turn, the balusters are installed so that the aesthetics of the fence are maintained - one per step, two per step, or otherwise.

Stair step length

The length of the step is determined by the design of the staircase. If two bowstrings are used as the main structural element- the length of the step corresponds to the distance between them. If there is a stringer (one or two), then the length of the step is determined by the customer.

Rule 4 - Accurate calculation of the dimensions of the stairs

Since all the parameters are interconnected, to calculate them, it is enough to have basic knowledge of geometry. We will show you how to calculate a staircase using an example.

Example 1. Calculation of the length of the stairs and the width of the opening

In this case, the calculation is simple and suitable for those who have a lot free space in the room.

How to calculate the length of stairs in a house

Defined as follows. To the room height of 3000 mm, a ceiling width of 200 mm is added. The resulting value is 3200 mm. divide by 160 mm (recommended riser height) and we get the number 20. That is. the staircase will contain 20 steps.

Based on the fact that the recommended step width is 300 mm, the length of the stairs should be 6000 mm (20 steps of 300 mm each). Or, if the step is extended by 50 mm, then the length of the staircase will be 5000 mm (20 steps by 250 mm (300 mm - 50 mm)).

How to calculate the width of a staircase opening

It is determined as follows: 1900 (recommended clearance value) is subtracted from 3000 mm (room height). We get 1100 mm. We divide this value by 160 mm (step height) and get the number of steps above which the ceiling can be located. The calculation result is 6.875, i.e. 7 steps.

The remaining 13 of the 20 steps must be located in an area free of overlap. Otherwise, walking under them will be uncomfortable. The width of the step is 300 mm, then the width of the opening will be 13x300 mm = 3900 mm.

We check 1100 (overlap width) + 3900 (opening width) = 6000 (staircase length)

However, not everyone has the opportunity to leave 6 or 5 meters under the stairs. In this case, it is worth playing with the width of the step or the height of the tread. Or you can make a staircase with a turn or with “duck step” steps. Such structures are more complex, which means the calculation will also be more complex.

An example of a drawing of a metal staircase on one stringer

Example 2. Calculation of the angle of inclination of the stairs and parameters of the steps

These calculations are more complex and can be performed using several methods. Among them the following are known:

• computer method;
• Danish method;
• line lifting method;
• sweep method;

What these methods have in common is the need for basic design knowledge. The diagram of the staircase in a graphical interpretation obtained using the methods described above is shown in the figure.

• method of proportions.

Suitable for a beginner in the field of design and allows you to easily calculate both a straight line and stairs with winder steps or a spiral one. After all, there is a peculiarity here, namely, the steps narrow towards the center.

Calculation of a metal or wooden staircase with winder steps of 90 and 180 degrees using the proportion method is based on the uniform distribution of space on the turning section. The calculation is performed as follows:

1. a sketch of the staircase is made in horizontal projection;
2. a line is indicated showing the average length of the march. For convenience, we will place it in the middle;
3. a line indicating the middle of the staircase turn is indicated. The place where the longest step will be located.
4. We plot the width of the steps on the middle line. Thus, their number can be calculated. The calculation is carried out from the turning line.
5. We determine the points where the last identical steps will end. There should be two such points - at the beginning and at the end of the stairs. In rare cases, stairs begin or end with winder steps;
6. in the place where the step will have a minimum width (near one of the stringers, a bowstring or a screw pipe, we set aside 50 mm from the turning line. In total, 50+50 will give us 100 mm. Which is the minimum allowable width of the step;
7. we connect the marked points with the previously marked points that show the width of the step and extend them to the opposite side (the second stringer, bowstring or railing of a spiral staircase).
8. set aside the remaining steps. Approximate proportion 1:2:3. One mm on the narrow part of the stairs is equal to 2 mm on midline and 3 on the wide part of the turn.

The data from the sketch is transferred to the staircase blanks in accordance with the scale.

The diagram of a staircase with winder steps and a 90-degree turn is clearly presented in the drawings

A staircase with winder steps with a 180-degree turn is calculated in a similar way.

The diagram of a staircase with winder steps with a 180 degree turn is presented below

This method of calculation cannot be called ultra-precise, but calculations sufficient to build a staircase with your own hands can be obtained. If you don't trust him, you can contact a specialist or use a computer program.

Calculation of stairs on bolts

The process is similar to calculating a staircase with winder steps. The only difference is in the method of fastening. The option of mounting on a wall string or without it is possible.

Calculation of a spiral staircase

The calculation of a spiral-type staircase is carried out similarly to the calculation of winder steps. But in this case, you need to accurately determine the configuration. From a design point of view, there are four types.

Note. The spiral staircase is considered the most dangerous in terms of movement.

Drawings of spiral staircases

Duck step ladder calculation

This configuration is good because it takes up minimal space, but such stairs are very troublesome to manufacture and operate. A duck step ladder is installed if the slope angle exceeds 45 degrees, and there is no desire to use an extension ladder. The peculiarity of this design is that only one leg rests on one step. However, despite this, the design of the frame of such a staircase is no different from the frame of a marching staircase. The only difference is in the shape of the steps.

Goose step staircase diagram

Note. According to the standard, the number of steps in a duck step staircase should be odd. Moreover, it is preferable to do the first step on the right. This is because most users have their dominant foot on the right. The maximum tread is also set to the right.

Computer programs for calculating stairs

The software method allows you to create a 3D project, visualize the project and obtain a drawing of the staircase with an accurate indication of all parameters. The most widespread programs are:

• “Compass” (as practice shows, most craftsmen are familiar with this program);

• SolidWorks - allows you to create the design of various engineering structures, not just stairs;

• Consultec Staircon - makes it possible not only to create a staircase project, but to calculate an estimate for its construction. A complete three-dimensional model allows you to get a complete picture of the future design.

Rule 5 - Detailed drawing or sketch

Calculation using a computer method or the method of proportions already presupposes the presence of a drawing of the future staircase. However, even those who make a simple staircase should create a sketch with dimensions marked on it.

Note. On the sketch you need to put not only the parameters of the staircase, but also indicate the main parameters of the room. For example, the presence and size of a window, a protruding part of a window sill, columns or other objects that can be placed change the configuration or parameters of the staircase during work.

Having thus prepared, you can begin building the stairs with your own hands.

Winder steps are called steps whose width increases from inside to the outside. Naturally, the calculation of the winder steps must be carried out with special care at the stage, since the safety and convenience of the entire staircase design, either spiral staircase or a straight march turn. Most often, winder steps are made when it is necessary to reduce the dimensions of the staircase by eliminating the interspan platform from its design. At the same time, a place with non-standard steps becomes not very convenient, especially for descending, because closer person steps to the inner edge, the less space there is to place your feet.

Primary requirements

When creating a staircase with winder steps, you need to adhere to several basic rules:

1. The outer part of the steps should not be wider than 40 cm.
2. The minimum for the inside is 10 cm (meaning its useful area, not the very edge).
3. The middle of the march is 20 cm, and this value must be observed throughout the entire structure.
4. The radius of curvature that characterizes the rotating part is 30 cm minimum.

Important! The course of the winder steps should not be tortuous, otherwise walking along it will not only be inconvenient, but also dangerous.

Calculation of the winder staircase can be made various methods, depending on the angle at which the staircase turns.

The proportion method, with some amendments, is also used to calculate the parameters for rotation at a right angle (90°). It should be noted that this is the simplest method; other graphic methods are more complex and require basic knowledge of drawing and design.

The method, called Danish, is also used when calculating 90° and 180° rotations of stairs. First of all, a horizontal projection is constructed, on which, as in the method of proportions, a line is drawn to the middle of the march. This line is also divided into segments the size of the width of the step. Then you need to decide on the beginning of the winder steps, the boundary is marked by point A. Another important point is the beginning of the winder step, located in the middle of the turn, indicated by the letter B.

Then half the line of the middle of the march with the tread marks is turned out so that a straight line is obtained, and a perpendicular is drawn from each mark. For the mark that marks the first winder step (after the straight ones), the length of the perpendicular is chosen equal to the width of the tread. For the mark at the opposite end of the unfolded straight line (the mark of the winder step located in the middle of the turn), the length of the perpendicular is taken equal to the minimum width of the steps. The two resulting perpendiculars are connected to each other, and the values ​​of the lengths of the perpendiculars for all other marks are obtained. The resulting segments are placed in ascending order into one straight line, which is projected onto a straight line equal in length to AB. This gives full information

about narrow sections of steps. The found dimensions are transferred to a horizontal projection (to line AB) and, by connecting the points with the marks on the mid-flight line, the full dimensions of all winder steps are obtained.

Other methods

When using the sweep method and line lifting method, the horizontal and vertical curvature of the rotary structure is taken into account. In the development method, the first step is to determine the boundaries of the steps, after which the drawing is transferred to a vertical projection. Similar to the manipulations performed in the Danish method, the markings are placed so that the resulting segments can be transferred to another plane by drawing perpendicular lines.

The vertical axis of the vertical projection, in turn, is divided into segments equal to the height of the steps. Next, straight steps are selected and, by connecting their edges with lines, the corresponding segments are obtained, with the help of which the intersection with the horizontal projection axis is found. The resulting point is used later to construct circles that are needed to determine the vertical projection of the bowstring lifting line. To find the tops of the steps, use the vertical axis - draw a line perpendicular to it until it intersects with the ascent line. Projections of the obtained points onto the horizontal axis will give the dimensions of the narrow parts of the winder steps. These dimensions are used to find all other parameters of the winder steps.

Slope of flight of stairs

An important characteristic of a staircase is its steepness, in other words, its angle of inclination. Not only the ease of use of stair equipment, but also safety depends on the steepness. The human stride, its average, is the main guide. In other words, the convenience of moving up stairs requires maintaining a certain proportion between the height of a person’s rise with each step and the distance by which he moves forward. Normally, the ratio of the height of the staircase structure to the length of its projection on the horizontal axis is in the range from 1:2 to 1:1.75. When these proportions are expressed in angular units, it turns out that the slope of the staircase structure should not be more than 30°.