What are the Components of a Staircase ?

Stairs are structures made with a series of steps arranged in a sequential manner so as to connect different floors of a building. Stairs provide access from one floor to another. 

Stairs are built either with concrete, masonry, steel, or wood. Wooden Stair is not a durable solution as they cannot take heavy loads.

Stair - Components, Types, and Features

Components of Stairs

The main components of stairs include:

1. Step
2. Riser 
3. Thread
4. Nosing
5. Scotia
6. Stringer or Stringer Board
7. Balusters
8. Hand Rails
9. Base Rail or Shoe Rail
10. Newel 
11. Balustrade
12. Railings 
13. Finial
14. Volute
15. Rosette
16. Easings
17. Fillet
18. Waist Slab
19. Walking Line
20. Head Room
21. Flight
22. Landing Slab
23. Staircase

1. Step of a Stair

The step is a combination of thread and riser. A step has a height called the "riser", a width called as the "thread" and a length. The upward and downward movements between the floors are made through the steps.

2. Thread of a Stair

The thread of a stair is the horizontal part of the step. This is the part of the step over which the foot is placed for the downward and upward movement.

3. Riser of Stair

The riser is the vertical part of step between the two adjacent threads of two adjacent steps. This vertical member supports the thread.

Fig.2. Stair Step, Riser, and Thread

Note: 

1. The distance between the upper surfaces of two adjacent step is called as rise of step.
2. The distance between faces of two consecutive risers is called as going of the step. (Figure-2)

4. Nosing of a Step

The outward projecting portion of the thread is called a nosing. It gives the step a pleasing and finished look. A nosing also ensures the safety, and protection of the step and improves its visibility of the step.

Fig.2. Step Nosing; Image Courtesy: Stoneconcrete.com

[Also Read: Different Types of Nosing Used in Staircase Construction]

5. Scotia of a Step

Scotia is a wooden block structure used to support the nosing (Figure 3). It is a unit provided mainly in wooden staircases.

Fig.3. Scotia of a Stair Step

6. Stringer or Stringer Board of a Stair

A stringer or stringer board is a housing structure that is used to support the stair. It is a type of housing that is provided on either side of the stair. The figure-4 shows a stringer board. Stringers can be of different types.

Fig.4. Stringer or Stringer Board of a Stair

[Also Read: Different Types of Stringers Used in Staircase Construction]

7. Hand Rail of a Stair

Handrails are bars that run at a particular distance above the steps throughout the flight. These rails are provided to hold the hand and walk through the star.(Fig.5)

Fig.5. Handrail, base rail, newel post, and a stringer of a Stair

8. Base Rail or Shoe Rail of a Stair

A base rail is also called a bottom track. It is also a rail running parallel to the handrail along the top of the stair string. Stairs may or may not be constructed with a base rail (Fig.6. Stairs without a base rail). It adds a good finish to the stair and stringer.(Fig.5)

9. Newel Post of a Stair

Newel posts are vertical supports provided at the start and end of every flight to support the ends of handrails. A newel post is also called a principle baluster. (Fig.5).

10. Finial or Newel Post Cap

The ornamental top of the newel post is called a newel cap or finial. (Fig.5 & 6).

11. Balusters or Spindle of a Stair

Balusters or spindles are vertical members running between the newel post in a particular interval. They hold up the handrails. For a stair with hand and base rails, the balusters are located between them. A staircase can be constructed with or without balusters. (Fig.5. Staircase without balusters- Only a glass panel provided).

Fig.6. A staircase without base rail, but has handrails and balusters or spindles

12. Volute of a Stair

A volute is a spiral scroll-like ornament at the start of the staircase (bottom). It is commonly used for wooden stairs. They provide a historic touch to the stair. (Fig.7). Volute provides support to the handrails and the railings.

Fig.7. Volute of a Stair

 

13. Balustrade or Banister of Stair

The balustrade or banister is the total framework that constitutes the handrails, the balusters, and the newel posts.

14. Railing of a Stair

The whole framework that supports the handrail is called railing. It is a safety feature of the staircase.

15. Easings

Easings permit the easy transition of handrails from one direction to other. They are mainly of three types:

• Up Easing
• Down Easing
• Goose-neck

Up Easing is used to make the transition up at an angle between two handrails or a fitting and a handrail, such as transitioning between a flat volute and a stair rail.

Overhand or Over Easing are used for the exact opposite situation. Making the transition down at the angle between two handrails or a handrail and fitting. For example: from a level handrail at the top of a stair to the stair rail below.

Fig.8. Up-Easing and Over-Easing in Stairs

Goose-neck is the part of the handrail that is used as a transition connection between two handrails running in different levels as shown in figure-9.

Fig.9. Goose-neck of a Stair

16. Rosette of Stair

A rosette is an ornamental unit that is at the end of the handrail that ends at a wall.(Fig.10)

Fig.10. Rosette of a Stair at the end where handrails stop at the wall.

17. Fillet of a Stair

Fillet is used to fill in the plow between balusters on the plowed handrail and shoe rail.

Fig.11. Fillet of a Stair

18. Waist Slab

The waist slab is a slanting slab that runs along the flight. A shown in Figure 12, the slab between the floor slab and the landing slab is called a waist slab. The waist slab can be imagined as a ramp without steps on it. 

Fig.12. Different types of stair with and without waist slab

19. Walking line

A normal person tends to walk along a line that is nearly 45 cm from the center of the hind rail. This imaginary line through which a person is most obvious to move through the flight is called a walking line.

20. Pitch and Line of Nosing

The line of nosing or nosing line is the line obtained by joining the ends of the nosing of each step as shown in figure-13. The pitch of the stair is obtained by determining the slope of the line of nosing.

The nosing line is also called as pitch line. The pitch or slope of the stair is the ratio of rise to going of the step.

 

Note:

• Very large slope or less slope is not good for a comfortable walking through the steps. 
• The pitch of the stair must lie between 45 degrees and 25 degrees.

Fig.13. Pitch and Line of Nosing

 

21. Headroom

Headroom is the perpendicular height difference between the line of nosing and the nearby top ceiling. The headroom is always designed such that there is enough space to accommodate the person's height while walking through the step.

22. Flight

The flight of stairs is defined as a series of uninterrupted steps or continuous steps between two floors or a series of steps between the landings.

23. Landing Slab of s Stair

The horizontal slab that is provided between two flights in a staircase is called a landing slab.

24. Staircase 

A staircase or stair is the whole arrangement of steps constructed to access the vertical distance between the two floors of a building.

Read More: Classification of Stairs Based on Utility