TO protect people from injuries and to facilitates access during movements from one level to another in a building Stair should be placed at a central place in the building so as to give shortest access to all rooms. It should be well ventilated and airy.
Floors situated at different levels are connected for communication, by any of the following methods (1) Ladders. (2) Steps-stairs (3) Escalators
(5) Ramps and chuts.
These are made of two side support, called up rights, either of wood, bamboo, mild steel, cast iron or pipes spaced with horizontal rugs. These can be portable or fixed as the need be. Wooden rungs held into twisted upright ropes are also very light ladders; these are mainly used in ships, boats and sea-trailers etc.Such ladders are also used for painting white washing in tall buildings 2) Steps:
Steps made in the form of a series of rising footing is termed as stair. A couple of steps built in series is known as a flight. Stair can be made into many shapes and designs out of any building-material 3) Escalators:
These are steps fixed on very slow moving belts. These are called moving stairs. These help in reducing the climbing time of stairs and are used at public places having vary high intensity of public movement. Like bus terminals, railway stations air ports etc 4) Lifts:
These are ventilated encased chambers which can be moved up and down in a shaft connecting different floors of a structure. These are high and low speed lifts. Lifts are electrically operated. Certain towers and sky-scrapers have lifts operating on outer faces of the structures. They are fixed with plexi glass and give the users a better view of the outside scenery around. 5) Ramps and chuts:
These are solid or inclined laid slabs between two floors situated at different levels. The normal gradients are 1 in 20 to 1 in 50. These are used in hospitals, multi storeyed parking area. swimming pools and children parks also have ramps, which are used for recreational purposes.
Trolleys made in the form of cabs are held on guy ropes and operated up and down between two different levels. These are mainly installed to connect two banks of a deep valley.
COMPONENTS OF STAIRS
Tread: The horizontal member which forms the upper surface of a step is called tread. Riser: It is the vertical front portion of a step. Rise: It is the vertical distance between the two upper surfaces of two successive steps. Nosing: The front edge of a tread is termed as nosing. Line of nosing: Imaginery line joining the nosings and parallel to the slope of stair is termed as line of nosing. Flier: A regular and rectangular step is known as flier. Flight: A series of continuous steps between two floors, or floor to landing or landing to landing is helps in turning of stair. Landing: This is a horizontal platform which is provided between two flights to serve as a rest. It also helps in turning of stair. Slope or Pitch: The angle between the line of nosing and floor is known as slope. 11. Strings and stringers: These are inclined members which support the steps. The strings may be provided on each of a step or in the centre to support steps as cantilever extending on each side. Soffit or plancer: Under surface of a flight is called soffit. Balusters: Vertical members which support the hand rail are known as balusters. 14. Hand rails: Hand rails are provided on top of...