What Is Stair?
A set of steps leading from one floor to the other, as a facility provided for vertical conveyance, is known as a stair. Stairs are provided to aﬀord the means of ascent and descent between the floors of a building. A room or an enclosure in a building where the stair is located is known as a staircase. And, the space occupied by a stair is known as a stairway. There are different types of stairs like straight stair, dog-legged stair, circular stair, etc used in buildings.
The stairs can be constructed of many kinds of materials such as wood, reinforced cement concrete, bricks, stone, steel, etc. . Nowadays, a portion of stairs is also constructed using glass and fibres.
A stair is an alternative to the elements like lifts and elevators, ramps, ladders, and escalators, which are also the means of vertical conveyance in a building. Among all of them, stairs are the oldest means of transportation used for vertical conveyance in a building.
How Should An Ideal Stair Be?
The requirements of a good stair are as follows:
1. Location of stair – A stair should be located such that it provides easy access to the people living in the building and where it is convenient for most of the people to use easily.
2. Breadth of stair – the width of stair shall be kept wide enough so that the person accessing it can use it without any inconvenience or any discomfort. The minimum width of stair should be 90 cm, in a residential apartment and between 1.5 m to 1.8 m in a public building.
3. Flight length – a single flight of stair should not contain more than 12 steps and less than 3 steps. It is decided from the comfort point of view.
4. Head room – a staircase shall be given a minimum headroom of 2.1 m to 2.3 m so that it allows even a tall person to comfortably access the stair with luggage on his or her head.
5. Safety – in case of an open well stair, balustrade should be provided for safety. Also the provision of handrails, is necessary on both sides of it.
6. Size of steps – the width of a step should be kept in such a way that a person can comfortably rest his or her foot on it and the height of a step is kept such that it allows a comfortable lift of leg, without any discomfort or inconvenience. The height of a riser should be between 12 cm to 18 cm and the tread should be kept between 28 cm to 35 cm.
7. Construction materials used for of stair – the materials used for construction of stair should possess suﬃcient strength. They should withstand the desired load and also they should have properties of fire resistance.
What Is Dog-legged Staircase?
Dog-legged staircase is given its name due to its appearance in the sectional elevation. When the sectional elevation of a dog-legged staircase is seen, it looks like a dog’s leg.
A dog-legged staircase falls under the category of newel stairs (or solid newel stairs), in which the newel posts are provided at the beginning and the ending of each flight of stair.
Dog-legged staircase is also called half-turn stairs because it is the one which has its directions reversed or changed for 180 degrees. Such type of stairs are quite common and are mostly observed where space is either less or it is to be eﬀectively utilized.
For compact spaces, dog-legged stairs are the most suitable stairs. It consists of two flights that go in the opposite direction. When a flight is finished, a mid-landing is provided. The mid-landing diverts the stair direction. The other flight runs in exactly the opposite direction to the first one.
Advantages Of Dog-legged Staircase
The advantages of dog-legged staircase are as follows:
1. Privacy – when there is a requirement of privacy, the dog-legged staircase is best suited. The elevation of dog-legged stairs is constructed in such a way that both the connected floors are separated in a way and the privacy is maintained.
2. Eﬃcient use of space – dog-legged staircase is very useful where the space is compact. It utilizes the provided space in an eﬃcient way, covering a lesser area of the space.
Disadvantages Of Dog-legged Staircase
1. Complex construction – the construction of dog-legged staircase is a bit more complex as compared to the other types of staircase.
2. The handrail of dog-legged staircase requires proper planning.
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