What is Stair?
Stairs are the important parts in building structure. They are useful to go from one floor to another floor. There are various types of stairs like straight stair, spiral stair, open newel stair and dog legged stair, etc, used in residential building, commercial building and industrial building etc.
Stair is important component of building structure. So, in this blog, we will discuss Components of Stairs and Types of Stairs.
Components of Stairs
The different components of stairs are given below.
Step
It is part of a stair (combination of tread and riser) which allows ascent and descent from one floor to another floor.
Tread
It is the horizontal part of the step on which the foot is placed during ascending or descending a stair.
Riser
It is the vertical part of the step which is used to connect and support consecutive treads.
Rise
Rise is defined as the vertical height between two successive treads.
Landing
Landing is defined as a horizontal member between two consecutive flights of stairs. It provides the change of direction as well as use to take rest during the use of the staircase.
Nosing
Nosing is defined as projecting part of step after the face of the riser. It is used to give a good aesthetic view to step.
Going
Going is defined as horizontal distance between two successive risers.
Flight
A continuous run of steps without between landing and flooring or two landing without any break is known as flight.
Head Room
Headroom of stair is defined as vertical distance between the tread of one flight and ceiling of overhead construction.
Hand Rail
Handrail is defined as an inclined member provided at suitable height over balustrades. The inclination of the handrail should be parallel to the slope of the stair.
Baluster
Baluster is defined as an individual vertical component used to give support to handrail and fixed between handrail and string. It is made of metal, timber or masonry.
Balustrade
Balustrade is also known as barrister. It is defined as a framework of handrail and series of balusters.
Pitch or Slope
Pitch or Slope of stair is defined as vertical angle between nosing line of the stair and horizontal line.
Run
Run of a stair is defined as total length of stair involving landing of stair.
Soffit
Soffit of stair is defined as undersurface of stair. It is finished with the plaster.
Scotia
Scotia is defined as extra moulding facilitated under the tread or nosing to give a good aesthetic view to steps.
Newel Post
Newel post is defined as a vertical member provided at where the balustrade changes direction. It is used to provide support to handrail.
Strings
String of stair is defined as an inclined member of stair used to give support at the end of the steps.
Waist
Waist of the stair is defined as the thickness of the RCC slab on which the steps of the stair rest.
Types of Stairs
Based on arrangement of steps, stairs can be divided into the following types:
- Straight Stair
- Open Newel Stair
- Dogged-legged Stair
- Circular Stair
- Geometrical Stair
- Spiral Stair
- Bifurcated Stair
- Quarter-turn Stair
Straight Stair
In a straight stair, all the steps are positioned continuously along in a single direction. One flight may be divided into more than one flight by placing a landing. Straight stair is useful where long and narrow space is available for a stair like porch, entrance etc.
Open Newel Stair
In the open newel stair, two flights or more than two flights arrange an opening between the forward and backward flights. Open Newel Stair is mostly used around the lift in the building.
Dogged-legged Stair
The dogged-legged stair consists of two straight flights and one landing with direct turns between two straight flights. This stair is very useful where the width of the stair is just twice the width of the flights.
Circular Stair
In a circular stair, all the steps are arranged from a well hole in circular direction. This stair is used at the back side of a building to use all floors of the building.
Geometrical Stair
Geometrical stair is similar to the open newel stair but the shape of the open well between forward and backward flight is curved.
Spiral Stair
The spiral stair is similar to a circular stair. In this type of stair, steps radiate from the centre column in a circular direction. The diameter of the spiral stair may change from 1 m to 2.5 m.
Bifurcated Stair
In bifurcated stair, main flight is subdivided into narrow flights at the mid-landing. The narrow flights initiated on both sides of mid-landing. This type of stair is used in modern residential buildings as well as modern public buildings.
Quarter-turn Stair
The stair which is turm at 90° at level of landing is called Quarter-turn Stair.
Conclusion
Staircase is the important element of any building structure. So, As a civil engineer, it is mandatory to know the components of staircase as well as types of staircase. In addition, selection of types of staircase is depend on different factors such as availability of spaces, budget, usability and aesthetic of home etc.
FAQs
What are the different types of stairs?
The most common types of stairs are straight stair, open newel stair, dogged-legged stair, circular stair, geometrical stair, spiral stair, birfucated stair and quarter turn stair etc.
What are the uses of stair?
Stair is used to go from one floor to another floor. it also used to escape from home in case of fire.