In the suburban areas today, in order to save, they mainly build houses in two or three floors. In any case, an attic is available in almost every private residential building. And this means that the staircase is almost an obligatory element of any country house. When designing such a structure, it should be decided, including with such a parameter as the step height. You also need to correctly calculate the width of the march rises, their length and some other indicators. The design of the stairs should be mandatory taking into account the requirements of SNiP and GOST.
What are the stairs
Two types of lifting structures are usually installed in country houses - ordinary marching or screw. The first variety can also be rotary. Thus, there are also two types of steps - simple square (or semicircular) and trapezoidal.
It often happens that there is not enough space in the house to equip the site of the rotary staircase. In this case, it is replaced by running steps. In fact, such stairs are a transitional option from marching to spiral. Both types of hoists are used in their design - both trapezoidal and rectangular.
Standard sizes
The standards of GOST and SNiPa determine mainly the width and height of the concrete steps of multi-storey urban houses. The first indicator according to the standards should be 30 cm. Such a parameter as the height of the stairs, GOST requires determining taking into account the angle of inclination of the march. So, for access stairs, this indicator is usually 125-145 mm. For steeper basement and attic structures, the lifting height should be 143 or 168 mm. The width of the steps at such stairs is allowed to be reduced to 26 cm.
In a private house, this standard is strictly followed, of course, is not necessary. For such buildings, the specific width and height of the steps of the stairs are not determined by GOST . There are only certain limits of values, beyond which it is not recommended. When designing stairs in country houses, they pay attention primarily to the particular layout of the premises.
Stage design
Climbing staircases can be on bowstrings or kosour. In both cases reliable and durable marches are obtained. Structurally, the steps consist of two main elements:
- treads (horizontal part);
- riser (vertical part).
The width of the staircase march, according to the standards, should not be less than 0.9 m. But usually in private houses they build structures with a distance from the railing to the wall of about 1.2-1.5 m. The length and height of the steps of the stairs are in no way interconnected. When calculating the lift parameters, other factors are taken into account.
The riser in the design of the stairs is sometimes not included at all. This saves on material. However, marches without such an element look less solid and safe compared to ordinary deaf ones.
Regulations
When designing, you must adhere to the following rules provided by SNiP for marching stairs :
- the width of the tread should not be less than 20 cm;
- the upper step can hang over the lower one by no more than 5 cm;
- the height of the staircase should not go beyond 14-21 cm.
Screw structures are designed taking into account that:
- the narrowest part of the steps should not be less than 10 cm;
- the width of the trapezoidal step on the opposite side should not be more than 40 cm;
- along the central axis, the tread should have a minimum width of 20 cm.
Calculation formula
The necessary width (A) and step height (S) of the stairs are calculated according to the formula 2S + A = 590 ... 650 mm. The range of numbers from 590 to 600 mm is the average length of a person’s step. Thus, depending on the layout of the house, they are first determined with such a parameter as the step height. Next, calculate the desired number of climbs, find their width and the optimal angle of inclination of the march.
Calculation Example
Suppose the distance from the floor to the ceiling in the room is 275 cm. In this case, the desired step height is 17 cm. In this case, the number of lifts will be equal to 275/17 - 1 = 16.18 - 1 = 15.18. We round to an integer, we get 15 steps. We find the actual lifting height of 275/16 = 17.2 cm.
Now you can determine the width of the step. A = 63 cm - 2 * 17.2 cm = 28.6 cm, rounded to 29 cm. Next, you need to determine the projection on the floor. To do this, we simply multiply the width of the steps by their number. As a result, in our example, it turns out that the first step should be 15 * 29 = 435 cm from the wall. Knowing the height and projection, we can first determine the tangent tgA = 275/435 = 0.6321, and then the angle of inclination A = 32 degrees 18 minutes This does not go beyond the valid parameters.
What you should know about
Very often, stairs in a house are designed before an operation such as finishing the floor. In this case, the thickness of the future floor covering and insulation (if provided) should be added to the height parameter. All steps in the march must have the same height. Otherwise, walking up the stairs will be extremely uncomfortable and also unsafe.
In addition to the minimum and maximum permissible indicators, there are also optimal march stage heights. This parameter is 17 cm. The optimal width of this structural element of the staircase is 28 cm.
Height of steps of marches from different materials
When determining the parameters for climbing stairs, one more important factor should be taken into account. The height and width of the steps may depend, among other things, on the material chosen for the manufacture of the march. This rule does not apply mainly to concrete and metal stairs.
The standard width of the edged board, for example, is 150, 175 or 200 mm. Accordingly, the height of the step in this case will be equal to one of these values (minus the thickness of the lumber). In this case, it is impractical to choose another parameter. Otherwise, you will have to do too much time-consuming work to reduce the width of the boards.
The same goes for climbing brick stairs. The steps of such structures are most conveniently assembled in two rows. In this case, first the bricks are laid out on the bed. In the second row they are set on a spoon. The height of a standard brick is 65 mm, the width is 120 mm. As a result, we get a rise of 65 + 120 + 10 = 195 mm (5 mm each - to the seams).
Vertical stairs
Such designs are rare, but are used in private homes. Usually it is either attic stairs or leading to the cellar. The permissible range of distances between the bowstrings in this case is 0.45-0.80 m. The height of the steps (step between them) should not be less than 0.30 m and more than 0.34 m. The maximum length of the attached vertical staircase is 5 meters.
Such a design must necessarily be equipped with a device that prevents its shifting and tipping over. Approximately the same requirements apply to ladders.
What other standards exist
Of course, SNiPs determine not only how much the height of the step and its width should be centimeters. When designing a staircase, other standards must be taken into account:
- the height of the railing should not be less than 90 cm;
- the distance between balusters can not be done more than 15 cm;
- the minimum thickness of the tread board is 2.5-3 cm.
When designing swing stairs for private houses, among other things, you should pay attention to such an indicator as the height of the site above the floor. According to the regulations, this parameter should not be less than 1.9 m. But it is better to place the area between the marches higher - 2.5 m from the floor. Otherwise, people of ordinary stature passing under the stairs may simply hit.
In wooden lifting structures, all elements should be fastened with bolts. When using self-tapping screws, the ladder loosens very quickly. The first step is allowed to do just above the rest. In the march itself there should be no more than 18 climbs. However, it is desirable to make such long stairs rotary. Moreover, for each march there may be 9 steps (or, for example, 5 and 13). The depth of the upper platform of the stairs is determined by the width of the door leading to the room. The first parameter must be larger than the second.