When doing the ladder yourself, you must carefully perform all the calculations of the structure. Strength, reliability, safety and comfort during the operation of the product will depend on this.
Next, we will consider how to correctly calculate the flight of stairs for the further manufacture of the structure.
Marching staircase
Measurement of the room
Before starting the calculation of the flight staircase, it is necessary to measure the space in order to determine the dimensions of the future product. To do this, transfer the floor plan to paper, displaying there all the windows, doors, all kinds of obstacles, the arrangement of furniture and at the same time fix all the dimensions.
For example, our room has dimensions of 5000 x 2800 mm.
Next, you need to do the following:
First of all, it is necessary to measure the height of the floor from the floor of the first level to the floor of the room on the second level., taking into account the thickness of the floor. In our case, the height is, for example, 2.8 m.
Then the dimensions of the opening are measured, which in our case are 2700 x 1350 mm, and the thickness of the interfloor overlap is 200 mm.
These parameters are quite enough to perform further calculation of flights of stairs.
Design of a single-flight staircase
General information
The flight staircase can be of several types:
With one march;
With two flights and an intermediate staircase;
With two flights and winder (turning) steps.
As a rule, an intermediate platform is used in cases where the number of steps in the march exceeds 14-15 pieces. The division of the march into two parts ensures safety and ease of lifting.
The device of the marching ladder
In cases where it is necessary to save space, instead of a turntable, run-in stair steps are used. First, let's look at the most common and simplest solution - a staircase with one flight.
Calculations should answer the following questions:
How deep will the tread be?
What is the height of the step?
How many steps?
What will be the angle of inclination of the structure?
How much space will the product take indoors?
Are we not going to bang our heads against the ceiling and ascend?
How long should the supporting beams be?
In this case, the designed structure must meet the following requirements:
Maximum reliability and convenience;
Safe and comfortable approach for descent and ascent;
Safe and convenient location of the railing.
Advice!
The most optimal march width for an internal staircase is 0.9 -1 m.
In garden houses, a march width of 0.7-0.8 m is allowed.
Dimensions of the structure
To calculate the dimensions of the structure, we will draw the contours of the product on a premise prepared in advance. In this case, the angle of inclination should be within 30 - 45 degrees. The safety of the structure and the convenience of its operation depend on this indicator.
Knowing the location of the product in the plan, it will not be difficult to graphically calculate the angle of inclination.
Diagram of the relationship between the angle of inclination of the structure and the dimensions of the steps
Steps
As practice has shown, a staircase turns out to be the most convenient and comfortable if the following formula for calculating a staircase was used in the design: double the height of the step and summed up with the width of the tread is equal to the average length of a human step. The length of the step on the square is in the range of 62-64 cm, and the comfortable leg rise is 30-32 cm.
Optimal step sizes
As a result, we get the following formula - 2a + b = 64 cm, where the step height is denoted as "a" and the tread width as "b". Sometimes the following formula is more acceptable: a + b = 47 cm.
Note!
The step height must be at least 120 mm and not more than 170 mm.
For example, if the height is 12 cm, then based on the first formula, the tread width will be 40 cm. Such a tread will be too wide, in this case it is better to use the second formula. The tread width will then be 35 cm.
Of course, without resorting to formulas, you can use the optimal size, which lies in the range of 140-170 mm. To save space, let's take the maximum height - 17 cm. In this case, the march will have 2800/170 = 16.47 ~ 16 steps. To correct their height, we will perform the following calculation - 2800/16 = 175 mm.
Advice!
In stores, there are ready-made structural elements that can be selected in accordance with the required dimensions.
True, they still have to be "adjusted", and the price will be quite high.
Therefore, you can only buy complex elements that cannot be done on your own.
Since the last step coincides with the floor level of the second level, there should be 15 of them in the march. It is quite simple to calculate the depth of the treads using the same plan, for this you need to divide the length of the horizontal projection of the stairs by the number of treads. In our case: 4400/15 = 293 mm, which is an acceptable norm.
Note!
The edge of the tread has a projection of about 20-40 mm. Therefore, when making treads, it is necessary to add a few more centimeters of "overlap" to the resulting width.
Now, knowing how to calculate the steps of a staircase, you can proceed to the final design stage.
Scheme for calculating the length of the march
March length
Further, knowing the basic design parameters, we will consider how to calculate a flight of stairs in length, i.e. we find out the length of the bearing part - a bowstring or other support. It is very easy to do this using the Pythagorean theorem.
To do this, we will square the projection of the length of the product and add the square of the floor height, since our legs are the projection and height of the room, as shown in the figure. Then, from the resulting number, we extract the square root: 193600 + 78400 = 272000. We take the square root and get - 521.5 cm.
Passage height
The minimum distance between the upper edge of the tread and the ceiling must be at least 1900-2000 mm. As you rise, this value should not change. If this condition is not met, then it is necessary to increase the opening in the floor.
This completes the calculation of the march. If you make a staircase with your own hands, then based on the calculations obtained and the resulting drawing, you can start making parts of the future structure.
Additional information on the calculation of flights and the manufacture of stairs can be found in the video in this article.
Two-flight staircase project
Peculiarities
The calculation principle of this structure remains the same as the calculation one-flight staircasehowever, the following nuances are added:
If the staircase has a turn of 180 degrees, then the minimum distance between flights of stairs in accordance with paragraph 8.9 of SNiP 21-01-97 should be 75 mm. Accordingly, there should be no less distance between the railings.
The site is the same step, only it takes up more space. If the marches are performed at an angle of 90 degrees, then the site will turn out to be square.
Note!
If you cannot maintain the required distance between flights of stairs, moving on it may cause injury to the hand. Two-flight staircase
Winder steps
If the calculation of a structure with a turntable is not much more complicated than the calculation of a single-march structure, then the use of rotary steps makes this procedure more complicated. However, the instructions below will help you cope with this task.
In the photo - a winding staircase with a 180-degree turn
The most important thing is to produce winders in accordance with the following standards:
At the narrowest point, the width of the turning step must be at least 120 mm;
The width of the winder on the center line must be at least 20 cm;
The minimum radius of curvature should be 30 degrees.
It is easiest to calculate the winders in a graphical way, as shown in the diagram below.
Winder steps calculation scheme
Advice!
Please note that graphical calculations are not entirely accurate.
Therefore, in the process of drawing, it is allowed to change the size of the treads, but with the condition that the parameters of the middle line of movement cannot be affected.
The rest of the calculation corresponds to everything that has been written in relation to the one-flight staircase.
Output
Accurate calculation of the staircase march will allow not only to create a safe and comfortable staircase, but also to simplify the process of its manufacture. As a result, you will avoid many "alterations" and "adjustments" during the installation process and save time and building material.
