Closed stairwell: refers to the stairwell separated by fire-resistant building components, which can prevent smoke and hot air from entering. The enclosed stairwell is suitable for factories (warehouses), public buildings and residential buildings.

Smoke-proof stairwell: refers to a stairwell with a smoke-proof front room, an open balcony or a recessed corridor (collectively referred to as the front room) at the entrance of the stairwell, and the doors leading to the front room and stairwell are fire doors to prevent smoke and hot air from entering.

2. Scope of application

Closed stairwell:

(1) Factory building (warehouse):

(1) High-rise workshops and Class A, B and C multi-storey workshops; (2) High-rise warehouse.

(2) Public buildings:

(1) Medical buildings, hotels, old buildings and buildings with similar functions; (2) Buildings with song and dance entertainment places; (3) Shops, libraries, exhibition buildings, conference centers and similar buildings with functions; (4) Other buildings with 6 floors or above; (5) The podium and the second-class high-rise public buildings with the building height not exceeding 32m.

(3) Residential buildings:

(1) Residential buildings with a building height not exceeding 2 1m adjacent to evacuation stairs and elevator shafts; (2) Residential buildings with a building height exceeding 2 1m and not exceeding 33m.

Smoke stairwell:

High-rise factory buildings with a height of more than 32m and more than 10 people on any floor; A class of high-rise civil buildings; Class II high-rise public buildings with a building height exceeding 32m; Class II high-rise residential buildings with a building height exceeding 33m. There are 3 or more underground floors, and the height difference between the basement floor and the outdoor entrance floor is greater than 10 meter.

3. Setting requirements

Closed stairwell:

(1) The evacuation stairwell shall meet the following requirements:

(1) Stairwells should have natural lighting and ventilation, and should be set by external walls; (2) There should be no boiling water room, combustible material storage room and garbage chute in the stairwell; (3) There should be no protrusions or other obstacles affecting evacuation in the stairwell; (4) The stairwell should not be equipped with Class A, B and C liquid pipelines;

(two) the closed stairwell shall meet the following requirements in addition to the above provisions:

(1) When natural lighting and ventilation are not available, a mechanical pressurized air supply system or smoke-proof stairwell shall be set up; (2) The first floor of the stairwell can include the walkway and lobby of the stairwell to form an enlarged closed stairwell, but it should be separated from other walkways and rooms by measures such as Class B fire doors; (3) No other doors and windows should be opened on the inner wall of the stairwell except the door of the stairwell;

Smoke stairwell:

(a) the smoke staircase and its antechamber should not be equipped with roller blinds, and it is forbidden to cross or set flammable gas pipelines in the smoke staircase and its antechamber;

(2) Smoke prevention facilities should be set up;

(3) The front room area should not be less than 6_ for public buildings and high-rise factories (warehouses), and the front room shared with fire elevators should not be less than10 _; Residential buildings should not be less than 4.5_, and the front room area shared with fire elevators should not be less than 6 _; For civil air defense projects, it should not be less than10 _;

Baidu encyclopedia-closed stairwell

Baidu encyclopedia-smoke-proof stairwell