Before reading my this article about different types of staircase I highly recommend you to read my previous article about the component of stairs because there are sufficient names of element or component of stairs which may be unknown to you and make you more complicated to understand.
Stairs – The stair may be defined as a sequence of steps which is provided to afford the means of ascent and descent between the floors or landings. The room or space of a building in which the stair is located is known as a staircase.
A stair consists of treads, risers, stringers, newel post, handrails, and balusters, etc. Stair may be made from various materials like timbers, stone, bricks, steel and reinforced or plain cement concrete. The
selection of the type of material depends upon the number of factors like aesthetical importance, the interior of the building, funds available, desired durability, and expected fire-resisting qualities, etc.
The different elements of the stairs are given below:-
- Step: It is a part of the stair which permits ascent or descent from one floor to another floor. It is comprised of tread and riser. A stair is a combination of a number of steps.
- Tread: It is the uppermost (surface) horizontal portion of a step upon which the foot is placed while ascending or descending along the stair.
- Riser: It is the vertical part of a step providing support to the tread Tread and riser are the right angle to each other.
- Flight: This is defined as an unbroken series of steps between landing.
- Landing: It is the level platform at the top or bottom of a flight between the floors. A landing facilitates the change of direction and provides space-for taking rest during the use of stair.
- Rise: It is the vertical distance between two successive-tread faces.
- Going: It is the horizontal distance between successive riser faces.
- Nosing: It is the projecting part of the tread beyond the face of the
- riser:- It is usually rounded off from architectural consideration.
- Scotia:- It is molding provided under nosing to provide additional strength to the nosing.
- String:- These are sloping members who support the steps in a stair. They run along the slope of the stair.
- Baluster:- It is the vertical member of wood or metal supporting the handrail.
- Nosing:- It is an imaginary line parallel to the strings and tangential to the nosing. connect the ends of a strings and handrail
- Winders:-These are a special type of step used in place of landings. The direction of the step can be changed with winders without introducing landings. These steps are the radial one, which is wider on the external side than the internal side.
- Waist:- The thickness of the structural slab in case of the overhead structure.
- Handrail:- It is the rounded member of wood or metal provided at the side of a stair for safety and is fixed bout waist height parallel to the line of nosing.
- Pitch:- Pitch or slope is the angle which the line of nosing makes with the horizontal.
- Headroom:- It is the minimum clear distance in the vertical direction between the tread and overhead structure.
- Newel post:- Newel post is the vertical member which is placed at the ends of flight to connect the ends of strings and handrail.
The requirement of the good staircase:-
For safe communication between one floor to another floor, there should be provided a well planned and designed stair.
Stairs should be provided such that it makes easy and quick for ascending and descending from one floor to another. The general requirement of good stair may be divided into different categories, described below,
- Location:- Stairs should be so located that the sufficient light and ventilation is insured. If possible it should be located at the central part of the building so that It is easily accessible from every corner.
- The width of stairs:- Width of stairs varies with the situation and purpose for which it is provided. In public building, where the flow of people is regular using the stairs, the width should be sufficient whereas in residential building it should be just minimum. The generally adopted average value of for width of stair in public building is 1.8 m and in residential building is 90 cm.
- Pitch of stair:- The pitch of long stair be made flatter by it introducing landing to make the ascent less tiresome and less dangerous. In general, it should not be more than 40 degrees and less than 25 degrees.
- Length of flight:- For the comfortable ascent of the stairway the number of steps in a flight should be restricted to a maximum 12 for residential and 9 for public and minimum of 3m.
- Headroom:- The headroom should not be less than 2.14m. If it is short then ones may get an injury by colliding on it.
- Materials:- The stairs should preferably be constructed of materials which possess fire-resisting qualities. It must be strong enough to carry the load without deflection.
- Landings:- The width of the landing should not be less than the width of the stairs.
- Winder:- The introduction of winders in the stairs should not be avoided as far as possible. They are dangerous, difficult to the carpet, involve extra expense an unsuitable for a public building. If it is unavoidable, it should be provided at the lower end of the flight. For turning stair by 9 degrees, three winder steps and for turning stair by 180°, six winder steps should be provided.
Now let us move toward different types of staircase
The sequence of steps provided to access from one floor to another floor is known as stairs. And the room or space of the building in which the stair is constructed or located is known as the staircase.
According to space i.e types of staircase and types of building the design of stairs are prepared. So, for easy design and calculation of its dimension first of all you must have some knowledge of types of stairs.
The different types of staircase i.e stairs are as follows
1)Straight Stairs – types of staircase
The Stairs which run straight from one floor to another floor are known as straight stairs. It is used for small residential houses or may be public building where there is lack of space or rectangular space of small width.
This types of stairs may consist of single or more than one flight with a landing. It is easy to ascend and descend from one floor to another because it is straight. And easy to design as it have only to connect two point, at top and at bottom.
It is relatively easy to install component of straight stairs like railing and handrails while construction.
2)Dog-legged stairs-types of staircase
The types of stairs which consist of two straight stairs combined parallel to each other in opposite direction (i.e in 180° turn) of ascend and descend is known as dog-legged stairs. In these types of stairs landing is provided at It’s a turning point and kept at the mid level of their flights.
This types of stairs is useful where the width of the stairs-case hall is just sufficient to accommodate two width of stairs. This types of stairs are generally used in residential building. It is a little bit hard to construct than straight stair as it covers whole space of staircase.
3)Open newel stairs-types of staircase
Open newel is similar as dog-legged stairs but the difference is there exist some gape between the two flight which are parallel and in opposite direction (See in picture above). This types of stairs are provided where the width of the staircase is more and create difficult to accommodate the numbers of steps in the two flight in taking account of the maximum allowable limit of steps in each flight.
In short flight 3 to 6 steps are provided along the width of the hall (i.e in gap between the flight). There may be steps or may not along the gap of flight. If steps are provided then landing after and before these steps are known as quarter space landing, if steps are not provided then the landing is known as half space landing.
This is not other than something modified form of open-Nobel stairs. There is a small difference that the open well between the forward and the backward flight is curved rather than rectangular. In this types of stairs, the turning point between two flights is obtained through wonders.
These may be either with half space landing or without landing. It is difficult to design and construct such types of stairs as it require precise measurements of the angle between steps of stairs.
The stairs in which all the steps provided radiate from the newel post or well hole in the form of wonders are known as circular stairs. Generally such types of stairs do not consist of landing and made up of cast iron but also with R.C.C. It is commonly provided at the back side of the building to access one floor to another.
It makes some difficult to ascend and descend as their steps are made whole with wonders having one side narrow and another side wide. So, these types of stairs are avoided for safe and quick access on floors. It’s construction is quite hard but it can be designed for an attractive look with arrangement of winders and railing style.
This is sweatable having narrow types of staircase.
In this types of stairs, the flights are so arranged that there is a wide flight at the start which is sub-divided into narrow flights at the mid-landing reaching at some level of height.
These types of stairs are generally provided in public building where large traffic have to ascend and descend continuously from either side of the block. This types of stairs are used widely in Hospital, Shopping mall, Universities etc.
I Hope friends, you liked my written article on “Different types of staircase” and remains helpful.