Study of Different Types of Staircase

Lecture No: 05

Parts of Stairs : 1. Step :It is a portion of stair which permits ascent & descent.2. Tread :It is the upper horizontal portion of step upon which the

feet is placed.3. Riser :The vertical portion between each tread on the stair.4. Handrail :A handrail is a rail that is designed to be grasped by the

hand so as to provide stability or support5. Baluster :It is vertical member of wood or metal supporting the

handrail.

6. Newel post :This is the vertical member which is placed at the ends of

flights to connect handrail .7. Run :It is the total length of stairs in a horizontal plane,

including landings.8. Nosing :It is the projecting part of the tread beyond the face of

the riser.It is rounded to give good architectural effect.9. String Or Stingers :These are the sloping wooden members which support

the steps in a stair .They run along the slope of the stair.

Main Parts of Stairs :

Standard Dimensions as per Byelaws

Type of Building Maximum Riser (mm)

Minimum Tread without nosing (mm)

Residential Building 150-200 300Public Building 180-200 250• Usually 150mm riser and 280mm tread should be

recommended for a good staircase.• Minimum width of staircase: Residential=1m,

Public=1.5m• Minimum Headroom: The minimum clear headroom in

any staircase shall be 2.2m• Width of landing: The width of landing should not be less

than the width of the stair.• Handrails: As per IS: 4912-1968 a stair railing shall be

provided with the vertical height not more than 85cm nor less than 75cm from the top rail to surface of tread.

Types of Stairs :

1. Straight Stair2. Dog legged Stair3. Quarter turn Stair4. Open newel Stair5. Three quarter turn Stair6. Bifurcated Stair7. Geometrical Stair8. Circular Stair

1. Straight Stair :

•These are the stairs along which there is no change in direction on any flight.

•It is used where stair case hall is long and narrow

2. Dog legged Stair :

•It consists of two straight flights of steps with abrupt turn between them. A level landing is placed across the two flights at the change of direction.

•This type of stair is useful where the width of the staircase hall is just sufficient to accommodate two width of stair.

3. Quarter turn Stair :

•A stair turning through one right angle is known as quarter turn stair.

•The change in direction can be affected by either introducing a landing or by providing winders.

4. Open Newel Stair :

•In these type of stair there is a well or opening between the flights in plan.

•This well may be rectangular or of any geometrical shape and it can be used for fixing lift.

5. Three Quarter Turn Stair :•A stair turning through right angles (270 degree) is known as three quarter turn stair.

•In this case an open well is formed.

6. Bifurcated Stair :

•These stair are so arranged that there is a wide flight at the start which is further sub-divided into two narrow flights at the mid-landing.

•The two narrow flight starts from either side of the mid-landing.

•These stairs are suitable for modern sub building.

7. Geometrical Stair :

•These stairs have no newel post and are of any geometrical shape.

•The change in direction is achieved through winders.

•The stairs require more skill for its construction and are weaker than open newel stair.

8. Spiral or Circular Stair :

It is known as spiral stair.

When viewed from top it appears to follow a circle with a single centre of curvature.

The spiral stairs are provided where space available is limited and traffic is low.

These stairs can be constructed in R.C.C., Steel or Stone

Some Amazing Stairs :