This document discusses the parts and types of stairs. It begins by defining what a stair, staircase and stairway are. It then describes the key parts of stairs including steps, treads, risers, handrails, balusters, newel posts, runs and nosings. Standard dimensions as per building codes are provided. The main types of stairs discussed are straight stairs, turning stairs (quarter turn, half turn, three-quarter turn and bifurcated) and continuous stairs (circular/spiral and helical). Turning stairs and continuous stairs are described in more detail.

1. Abhishek Singh
STAIRS
Abhishek Singh
Assistant Professor
Department of Civil Engineering
National Institute of Technology, Raipur

2. Abhishek Singh
Introduction
• A stair is a set of steps leading from one floor
of a building to another, typically inside the
building.
• The room or enclosure of the building, in
which the stair is located is known as
staircase.
• The opening or space occupied by the stair is
known as a stairway.

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Parts of Stairs
• Step
It is a portion of stair which permits ascent & descent.
• Tread
It is the upper horizontal portion of step upon which
the feet is placed.
• Riser
The vertical portion between each tread on the stair.
• Handrail
A handrail is a rail that is designed to be grasped by the
hand so as to provide stability or support.

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Parts of Stairs
• Baluster
It is vertical member of wood or metal supporting the
handrail.
• Newel post
This is the vertical member which is placed at the ends of
flights to connect handrail .
• Run
It is the total length of stairs in a horizontal plane, including
landings.
• Nosing
It is the projecting part of the tread beyond the face of the
riser.

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Parts of Stairs
• String Or Stingers
These are the sloping wooden members which support the
steps in a stair .They run along the slope of the stair.

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Standard Dimensions as per Byelaws
• 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.

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Types of Stairs

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Types of Stairs
• Straight stairs
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.

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Types of Stairs
• Turning stairs
Turning stairs are sub classified as
1. Quarter turn stairs
2. Half turn stairs ( dog legged stairs)
3. Three – quarter turn stairs
4. Bifurcated stairs

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Turning stairs
1. Quarter turn stairs
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.

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2. Half turn stairs ( dog
legged stairs)
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.
Turning stairs

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3. Three – quarter turn
stairs
A stair turning through
right angles (270
degree) is known as
three quarter turn stair.
In this case an open well
is formed.
Turning stairs

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4. Bifurcated stairs
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.
Turning stairs

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Types of Stairs
• Continuous stairs
This type of stairs neither have any landing
nor any intermediate newel post. They are
geometric in shape. These are may be of
following types
1. Circular stairs/Spiral stairs
2. Helical stairs

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Continuous stairs
1. Circular stairs/ Spiral
stairs
Circular stairs or spiral
stairs are usually made
either of R.C.C or metal,
and is placed at a location
where there are space
limitations.
These are not
comfortable because of
all the steps are winders
and provides discomfort.

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2. Helical stairs
A helical stair looks very
fine but its structural
design and construction
is very complicated.
It is made of R.C.C in
which a large portion of
steel is required to
resist bending, shear
and torsion.
Continuous stairs

17. Abhishek Singh
Thanks