Staircase: a) general view, b) horizontal sections (throws) individual storeys; 1 - external wall, 2 - inner wall (transverse), 3 - running with steps, 4 - inter-story landing, 5 - multi-story landing, 6 - clearance between gears (soul).
The following devices are used in buildings for vertical communication and transport of people and various objects:
a) stairs constantly,
b) moving stairs,
The stairs are divided into external and internal due to their location in the building. Due to the purpose there may be stairs: main, basement, attic, evacuation, etc.. Depending on the material used for the construction of the stairs, stairs are distinguished: stone, brick, wooden, concrete, reinforced concrete and steel.
The width and height of stairs should be adjusted to the average length of a human step, so that their use is not bothersome. The following elements are distinguished in the most common fixed stairs: runs with steps, we call landings and the ground clearance between the gears the soul. Room, in which the stairs are built in is called a staircase. The number of steps in one gear must not exceed 17, if the building is intended for the permanent residence of people, and not greater than 14 if the stairs are intended to be used to carry heavy objects on them. In the races that are comfortable for walking, it is assumed 10-12 degrees.
Usable clear width of gears, i.e.. between the wall and the railing, or between the railings should allow two people walking up the stairs to pass freely. This requirement does not apply to single-family houses.
The minimum width of the gears in the light should be:
80 cm - in single-family houses,
120 cm - in multi-family residential buildings without passenger and goods lifts as well as in public utility buildings and industrial plants,
140 cm - in inpatient health care units,
80 cm - flights of stairs in basements and attics.
The slope of the run tg α = h / s should be adapted to the length of the human stride. The average stride length is expressed as a relationship:
2 h + s = 60 ÷ 65 cm,
where h - step height, s - width.