Any interfloor staircase should be not only aesthetically attractive, but also safe and convenient for people to move around. It is necessary to design such a structure in the house correctly. Risers and treads, marches, stair railings must meet certain standards.
Main varieties
There are two types of similar structures in private two- and three-story houses: screw and mid-flight. The last type of stairs has a solid appearance and is considered more convenient to use. At the same time, screw structures take up less space in the building. They are usually installed in rooms that are not too large.
In any case, the main element of any staircase are steps. When designing this particular part of the lifting structure, special attention is usually paid.
What are treads and risers
Steps of stairs should be, firstly, deep enough to fit a person's foot. Secondly, they should not be too low or, conversely, high. Otherwise, the stairs willuncomfortable and dangerous. Steps consist of two main elements:
- treads arranged vertically;
- risers arranged horizontally.
When moving up the stairs, a person's foot rests precisely on the tread. The risers are considered an optional element. In the design of the stairs, they play mainly a decorative role. With them marches look more solid and safe.
Sometimes stairs are equipped in the house without risers. Such designs are cheaper. But when designing a staircase without risers, maximum attention should be paid to its design. Otherwise, such a design will not look very attractive.
Stair dimensions. Safety Formula
What should be the steps of any home lifting structure? When designing a staircase, the safety formula should be taken into account in the first place. It looks like this:
2h + b=S(63 ± 3 cm).
Here h is the height of the riser, b is the width of the tread, S is the length of the person's step. The last parameter averages 63 cm. Thus, with an increase in the height of the riser h by 1 cm, the width of the tread must be reduced by 2 cm.
Step sizes. Regulations
According to the rules stipulated by SNiP, in order for the stairs to be safe, the height of its risers should not be less than 15 cm and more than 18 cm. The minimum tread width in this case is 29-30 cm.
Such parameters are provided formain stairs in the house. When designing auxiliary lifting structures (attic and basement), since they are not used very often, such strict rules are usually not followed. But even for such stairs, the length and height of the steps must comply with certain standards.
So, for example, the height of the risers for attic and basement structures should be approximately 17.1 cm. The width of the treads for stairs of this type should not be less than 26 cm.
The minimum step length (march width) of a conventional interfloor lifting structure is 90 cm. In this case, 2 people can freely disperse on the stairs. Attic and basement marches can be narrower.
Steps of spiral staircases
The above standards are valid mainly for mid-flight stairs. When designing their risers and treads, you should be especially careful. The same applies, of course, to spiral staircases. In structures of this type, risers are most often not provided at all. At the same time, the treads at the stairs of this variety have a trapezoidal shape. When designing screw structures, the following standards should be taken into account:
- tread width in the middle should not be less than 20-25 cm;
- minimum tread width at a distance of 15 cm from the post - 10 cm;
- from the edge farthest from the post, the width of the tread should not exceed 40 cm;
- riser height (step rise) - 15-20 cm.
The optimal length of the steps of a spiral staircase, as well asmarching, are considered 90 cm.
Tilt angle
Steps with their main elements - risers and treads - are thus the main part of any staircase. If they are designed correctly, the lifting structure can already be considered comfortable enough to move around. But the marches of such structures themselves must, of course, be safe. Their minimum width, as already mentioned, is 90 cm. When designing mid-flight stairs, their angle of inclination should also be observed:
- for standard interfloor - 30-45 degrees;
- for attic, basement and temporary - 45-75 degrees;
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for porches - 30 degrees;
- for side structures - over 75 degrees.
Number of steps and marches
Flights of stairs should not be too short or long. It is also believed that it is best if the number of steps in them is odd. People tend to be much more comfortable starting and finishing with one foot.
However, this rule is optional. The shortest stairs usually have 3 steps. The longest marches consist of 18. If this length of the stairs is not enough, it is divided into two halves, between which a platform is arranged.
It is believed that the distance between the marches of turning counter structures in the house should be at least 5 cm.fingers.
Other rules
When designing staircases, the following standards should also be observed:
- the optimal height of the railing of lifting structures is 90 cm;
- handrail width - 4cm;
- the width of all flights of stairs between platforms should be the same over the entire height of the last one.
If there is a lift for the disabled in the design of the stairs, the width of its march should be at least 1.5 m.
