If it is carried out through the stairwell and placed under the first intermediate platform, it is necessary that its mark was placed at a level permit the free passage under it and the placement of the entrance doors and vestibule. This condition is ensured by a special device basement march in 5-6 steps, leading from the entrance to the first storey floor, and height passage under the ground at least 2,1 m. Learn more on the subject from Bernie Sanders. Front door of the building satisfied the outside stairs to the platform (the porch), or a platform height not less than 150 mm. Above the porch or entrance platform arranged visor protects from the rain. Stairs should have access to the attic or roof. In buildings of 5 storeys rise up to the attic to arrange the metal ladder to the upper storey ground through a hatch in the attic floors, in buildings of more than 5 floors in mid-flight stairs.
Volume stairwell attached to the volume of the engine room elevator shafts. Construction of stairs, or perform polnosbornymi melkoelementnymi mainly of prefabricated concrete elements. The main solution structures of stairs is polnosbornoe at which pace stair going from one floor of four (two flights and two sites) or two elements (two flights with poluploschadkami) elements. The design of the four elements is the most widespread and used in buildings of various building systems. Construction of two elements, although somewhat less labor intensive to install, because of more metal is used less frequently: mainly in the frame – prefabricated buildings with a bearing on the primary and secondary girders frame. Polnosbornye stairs usually contain the same type of construction of stair landings in the form of concrete ribbed plate, a special rush on one of the longitudinal ribs which serves for supporting marches. Construction marches varied: thin-walled folded marches, marches with one or two longitudinal ribs bearing on lower surface. Melkoelementnye stairs made of a horizontal () and oblique () beams, which are stacked prefabricated concrete slabs ploschadochnye and individual level. Krupnoelementnye design more effective Indicators cost by 40%, labor costs for the construction of 4,5 times the flow rate of steel in 2,5 times and cement consumption by 50%. Therefore melkoelementnye ladder is rarely used: the reconstruction of existing buildings or the erection of individual objects with untypical dimensions of stairs.