The Staircase is an important element for any building as it establishes the communication between two different levels. There are almost more than 25+ components of the staircase.
However, the construction of the staircase is one of the most complex works while constructing a building.
Apart from a few basic parts of a staircase, there are many other components used while dealing with a staircase.
Here, you will find basic information on all such components that you need to know if you are planning to monitor the construction of the parts of a staircase at your home. It is even helpful for purchasing different parts of a staircase.
Parts of a Staircase
The different parts of the stairs are as follows,
1. Stairway or Stairwell
A stairway is a total space in which the staircase is constructed.
The step is the basic structural and functional unit of a staircase.
(The major function of this staircase component to facilitate movement from one level to another is executed by the step; hence, it is the functional unit.
A set of steps together forms the staircase, without which the staircase cannot be built, hence it is the structural unit.)
One set of tread and riser together is called a step.
It permits ascent or descent from one floor to another.
3. Curtail Step
The starting footstep of the staircase is called the curtail step.
The width of the curtail step is more than that of the other steps in flight if the staircase is open on one side.
The wider step at the base eases the navigation. It also provides a wider base so that newel posts can be firmly fixed to the floor increasing its stability.
In staircase components, the flight is a continuous series of steps without any breaks. Thus, the total stairs from the start to a landing form a single flight.
Normally, a flight comprises 8-10 steps, after which a landing is provided.
The horizontal staircase component on which the foot is laid while ascending or descending through the staircase is called tread.
Tread width is the distance from one side of the stair to another. While tread depth is the distance between the outer edge of the step and the next intermediate riser.
The thickness of the tread is kept the same as that of the flooring. Normally, tread width is kept at 270 mm in residential buildings. Public buildings have a greater tread length of about 300 mm to accommodate more public.
Point to be noted: In a flight of stairs, the number of treads is always less by one than the number of risers.
Tip: If the number of treads is multiplied by the depth of the tread, it gives the horizontal distance over which the staircase is located. This is accurate only for the stairs that do not have nosing.
The vertical part or member that provides support to the treads is called a riser.
Rise: It is the vertical distance between two consecutive treads.
The rise in residential buildings is kept at 190 cm while in the case of public buildings, it is limited to 150 cm. This reduction ensures that the transition of people is smooth and nobody falls even in a congested situation.
Tip: Riser-less staircase is also gaining popularity in these years which are known as open-tread stairs due to their aesthetic appeal.
Generally, a tread does not end at the point of its intersection with the below riser. It is extended beyond the riser to a small length as an overhang, which is called nosing.
Thus, nosing is the horizontal protruding edge of tread in a staircase that is extended beyond the face of the riser.
Nosing is generally rounded at the edge. The length of nosing rarely exceeds 1.5”.
Nosing increases the space to place the foot in a staircase for easy negotiation through the staircase. It provides an architectural effect to the staircase.
Scotia is the additional block of the material provided the underneath nosing for its support.
It even helps in enhancing the elevation of the staircase.
Blocking is the additional material block provided in the underside of the steps for support to the step.
It is mainly used in the wooden staircase to prolong its durability.
Winder is a type of step that is narrower at one end. It is provided to avoid allotting a landing while changing the direction of the flight.
By employing a series of winders, a spiral staircase is constructed.
Read More: Staircase Reinforcement Calculation
Landing is a horizontal platform provided between two consecutive flights of staircase components.
It allows the person to take a rest before advancing onto the next flight.
If the direction of the stair is to be changed or two flights are to be merged into a single one as in the case of a bifurcated staircase, then landing is provided.
The horizontal distance between the successive risers measured from the nosing of consecutive treads is called going.
13. Pitch or Slope
The angle made by the line of nosing to the horizontal in a vertical plane is called pitch.
14. Line of Nosing
The imaginary line joining the tip of the nosing parallel to the slope of the stairs is called the line of nosing.
It is also called a pitch line.
The total length of all the flights in a staircase including the landing width in the horizontal plane is called run.
An inclined rail mounted on vertical posts at the ends is provided parallel to the slope of the stair to be held by hand for support during ascent and descent. This inclined railing at a convenient height is termed the handrail.
It is provided on either a single side or both sides of the staircase. In the wider staircase, another handrail is also provided in the middle.
It supports the user by preventing an accidental fall. Thus, it is an important component of the safety point of view.
The aesthetics of a staircase can also be increased by providing an attractive handrail.
17. Base Rail
If the baluster ends at a distance from the floor, then at the bottom end an inclined rail parallel to the handrail is provided between the vertical posts.
It is also known as a shoe rail.
The provision of base rail avoids the second baluster problem.
The vertical member on which a handrail is supported is called a baluster.
Its one end is connected to the top handrail and the other end is either connected to the bottom rail or embedded into the waist slab.
It also serves the safety purpose of preventing accidental falls.
Moreover, it can also be used to increase the aesthetic appearance of the staircase.
The entire framework of balusters along with the handrail is called a balustrade. it is an important staircase component.
20. Newel Post
In staircase components, the vertical member at the head and foot of a flight of stairs that supports the handrails by anchoring them is called a newel post.
It is a structural member extending up to the floor or subfloor and bolted into the floor joist.
21. Newel Cap
The top of the newel post is often enlarged to create a proper grip. This top is called a newel cap.
Different architectural shapes are available for the newel caps to improve the visual appeal of the staircase.
It is the underside of the staircase, i.e. the bottom of the stair slab.
It is sometimes embedded into the construction like a store or bath, if they are provided on the underside of the staircase.
The thickness of the RCC slab on which the steps of the staircase are rested is called a waist.
The thickness of the waist is perpendicular to the soffit of the staircase.
Stringer is a structural member parallel to the slope of the staircase in which steps are embedded for support on either side.
Sometimes, nothing is provided in the stringers so that the treads and risers can be accommodated properly in it.
In an open type stringer, its end is cut into the shape of the steps so that a visual effect is created. While in closed stringers, a straight inclined stringer parallel to the line of nosing is provided.
It is the vertical clear distance between the overhead structure of the staircase and the tread closest to it.
In most cases, this overhead structure is the ceiling.
Minimum headroom of 2 m is to be provided for the staircase.
Parts of a Stair with Characteristics
|Sr. No.||Components of Staircase||Characteristics|
|1||Stairway||Space in which staircase is provided|
|2||Step||The structural and functional unit of a staircase Consecutive riser and tread forms a step|
|3||Curtail step||The first step of a staircase Its width is more than that of other steps in the staircase|
|4||Flight||A series of steps without any landing 8-10 steps from a flight generally|
|5||Tread||The horizontal component of a staircase on which foot is placed while ascending/descending the staircase Minimum width: 270 mm (for residential buildings) and 300 mm (for public buildings)|
|6||Riser||The vertical component of a staircase on which a tread rests Rise: Distance between two consecutive treads minimum value190 mm (for residential building)150 mm (for public buildings)|
|7||Nosing||Overhang portion of a tread beyond the riser on which it is resting|
|8||Scotia||Additional block provided underneath the nosing|
|9||Blocking||Additional block provided underneath the step|
|10||Winder||A type of step whose width reduces from one to the other end Can be provided in place of landingUsed for the steps of a spiral staircase|
|11||Landing||A horizontal platform between two consecutive flights of stairs Allows a person to rest also provided when the direction of flight changes|
|12||Going||The horizontal distance between two consecutive risers|
|13||Pitch||Vertical angle between the line of nosing with horizontal|
|14||Line of nosing||The imaginary line joining the nosing in a flight|
|15||Run||The total horizontal length of all flights including landing|
|16||Handrail||Inclined rail parallel to the slope of the stair mounted on vertical posts at the end Provides support to the user during ascent/descent and also prevents accidental fall|
|17||Base rail||Inclined rail parallel to the handrail at the bottom of the baluster Provided when the baluster is not embedded into the floor also called shoe rail|
|18||baluster||Vertical member supporting a handrail throughout the run Prevents accidental fall|
|19||Balustrade||The framework of balusters and handrail|
|20||Newel post||Structural member at the start and end of the flight anchoring the handrail Embedded into the floor and bolted to the floor joist|
|21||Newel cap||Enlarged top of newel post for sound grip|
|22||Soffit||The underside of the staircase The bottom of the stair slab|
|23||Waist||The thickness of the RCC slab on which the staircase rests|
|24||Stringer||A structural member which accommodates the steps on either side|
|25||Headroom||Vertical clear distance between the floor on which staircase ends and ceiling Minimum value: 2 m|
What is the function of stringers in a staircase?
Stringers are the inclined structural members that support the treads and risers in a staircase. They provide stability and load-bearing capacity to the stairs, ensuring that the weight of individuals using the staircase is evenly distributed to the supporting structure.
What is the significance of a handrail in a staircase?
A handrail is an important safety feature in a staircase. It provides a secure grip and support for individuals while ascending or descending the stairs, helping to prevent slips and falls. Handrails are particularly crucial for people with mobility challenges, the elderly, and children.
What are newel posts and their role in a staircase?
Newel posts are large, sturdy vertical posts located at the starting, ending, and turning points of a staircase. They provide structural support to the handrail and balustrade, ensuring stability and safety. Newel posts also contribute to the aesthetics of the staircase, often featuring decorative designs.
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