The staircase is made up of different parts of stairs.
A stairs are arrangement of steps that allows the person to move from lower to higher floor or higher to lower floor.
A staircase made of wood has a stringer, treads, risers, railings, landings, and each parts has a specific purpose and lasting safe staircase.
Parts of stairs terminology:
Step: It is comprised of a tread and a riser; stairs composed of a set of steps.
Thread: It is the high flat or horizontal part of a step on which the foot is positioned for ascending or descending.
Riser: It is the vertical portion of a step offering support to the thread.
Rise: The vertical distance between two successive thread faces is known as rise.
Going: It is the horizontal distance between two successive riser faces.
Baluster: It is vertical member of wood or steel, supporting the handrail.
Balustrade: The mixed framework of handrail and balusters is called as balustrade, used to offer safety for the customers of the stair.
Hand rail: It is a moulded member of wood or metal, provided to afford assistance and safeguard to a person while going over a staircase, the handrails are fixed at the top of balusters.
Flight: A series of steps without an intermediate platform.
Nosing: The projecting edge of the tread is normally termed as nosing.
Pitch or slope: It is the angle which the line of the nosing of the stair makes with the floor is called pitch or slop.
Line of nosing: It is an imaginary line parallel to the string and tangential to the nosings.
Strings: These are the sloping members which assist the steps in a parts of stairs.
Scotia: It is a moulding offered under the nosing to enhance the elevation of the step and to supply power to the nosing.
Waist: The thickness of structural slab in case of plan R.C.C. stair known as a waist.
Newel post: These are principal posts supporting a handrail, positioned on the ends of flights to attach the ends of strings and handrail.
Headroom: It is the minimum clear vertical distance between the thread and overhead construction, i.e. ceiling.
Run: It is the complete length of stairs parts in a horizontal plane, including landings.
Header: The horizontal structural member supporting stair stringer or landings.
Soffit: The bottommost flat inclined surface of waist.
general requirements which a stair should fulfil:
A stair must be located in buildings where there is light and ventilation, it should be located to provide easy access for the occupants of the building.
If possible, the stairs parts should be located in the center so that it is easily accessible from different corners of the building.
Width of stair:
The width of the stair should be reasonable so that it can be carried without much inconvenience to the user, depending on its location and types of building.
Length of flight:
A flight should not contain more than 12 steps or less than 3 steps to give comfort and safety.
Pitch of stair:
The ascent and descent of a state should be relatively easy, there should be a ratio of going and rising.
Unstructured vertical height should be provided i.e. sufficient headroom.
It should not be less than 2.1 to 2.3 meters so that even a tall person can use a stair with the same accessories on his head.
Riser and treads must be in dimensions, so it provides customers consolation, their ratio must also be such that it will probably provide the desirable pitch of stairs.
Going through 30 cm shouldn’t be lower than 25 cm, the rise must be between 10 cm to 15 cm.
The width of the landing should not be decrease than the width of the stair.
Materials of construction:
It should be constructed of sound materials and with good workmanship, the material used for the construction for various parts of stairs should be as follows:
- Good workmanship
- Sufficient power
- Fire resistance
The number of steps in a flight:
The number of steps should not be more than 12 and not less than 3 for the comfort approach.
Stair Rise and Tread:
The treads and riser of a stair must be in suitable proportions for the purpose of ascent and descent.
The rise should be between 100 minutes to 150 mm and going should not be less than 250 mm and 300 minutes is quite comfortable.
The treads should be 250 mm to 325 mm wide, treads less than 250 mm width should have a hole of about 25 mm.
A staircase made of various parts has essentials for a safe and durability, various parts of stairs includes treads, risers, etc.