Staircase types & design or geometry of staircase is useful for civil engineering students in 2nd year of building construction subject. with will guide to students for understand requirements of good stairs, design dimensions,types of staircase etc.

1. Prof. Karan S. Chauhan
Assistant Professor
Department Of Civil Engineering
@ Shri Labhubhai Trivedi Institute Of
Engineering And Technology
Stair & StaircaseStair & Staircase
Subject :- Building Construction
Subject Code : 2130607

3.  A stair is a set of steps, leading from one floor to other ,
provided to afford the means of ascent or descent between
the various floors of building.
 The room or enclosure of building in which the stair is
located is known as stair-case.

5.  STEP: It’s a portion of stair which permits ascent or
descent it is comprised of a trend and a riser

6.  The upper horizontal of a step upon which the foot is
placed while ascending or descending

7.  It is the vertical portion of step providing a support to
the tread

8.  This is an unbroken series of steps between lading
 Its level platform at the top or bottom of a flight
between the floors
 Main reason for lading is providing some rest for the
climber

9.  Vertical distance between two successive tread faces.
 It’s the horizontal distance between two successive
riser faces

11.  It is the projecting part of the tread beyond the face of
the riser
 It is the underside of a stair

12.  These are the sloping members which support the steps
in a stair

13.  Newel post is a vertical member which is placed at the
ends of flights to connect the ends of strings and hard
rail…

14.  It is vertical member of wood or metal, supporting the
hand rail

15.  It is a rounded or moulded memoire of wood or metal
following generally the contour of the nosing line and
fixed on the top of balusters

16.  It is the minimum clear vertical distance between the
treads and overhead structure

18. 1. LOCATION
It should preferably be located centrally, ensuring
sufficient light and ventilation.
2. WIDTH OF STAIR
The width of stairs for public buildings should be 1.8 m
and for residential buildings 0.9 m.
3. LENGTH
The flight of the stairs should be restricted to a maximum
of 12 and minimum of 3 steps.

19. 4. PITCH OF STAIR
The pitch of long stairs should be made flatter by introducing
landing. The slope should not exceed 400 and should not be
less than 250.
5. HEAD ROOM
The distance between the tread and soffit of the flight
immediately above it, should not be less than 2.1 to 2.3 m. This
much of height is maintained so that a tall person can use the
stairs with some luggage on its head.

20. 6. MATERIALS
Stairs should be constructed using fire resisting materials.
Materials also should have sufficient strength to resist any
impact.
7. BALUSTRADE
All open well stairs should be provided with balustrades,
to avoid accidents. In case of wide stairs it should be
provided with hand rails on both sides.

21. 8. LANDING
The width of the landing should not be less than the
width of the stair.
9. WINDERS
These should be avoided and if found necessary, may be
provided at lower end of the flight.

24. • 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

27. • 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.

28. Changes direction either to left or Right by 900

31. • 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.

32.  Changes Direction in
opposite direction of by
1800.
1. Dog Legged Stair
2. Open Newel Half Turn
3. Geometric half turn Stair

34.  These may be of two
forms
1. Half space Landing
2. Quarter Space Landing
with winders
 No Space between Two
Flights

35. • 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.

36. • A stair turning through right
angles (270 degree) is known
as three quarter turn stair.
• In this case an open well is
formed.

37.  Direction Changed Three Times
 Limited Length of Stair Room
 Too large vertical Distance

39. • 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.

41.  Geometric Half Turn Stair
 Newel Post is not used in
this type of half turn stair
case

42. • 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.

43.  Public Buildings
 Wider Flight at bottom
 Bifurcated two narrow
flights, one turning left
and other right.

46.  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

48.  Space Limitation
 Emergency Stair
with winder steps
 Uncomfortable

49.  Very Complicated
Structural Design
and Construction
 Made of RCC

51.  The ratio of the going and the rise of a step should be well
proportioned to ensure a comfortable access to the stair
way.
 According to Basic Thumb Rule,
 (2 x Rise in cm) + (Going in cm) = 60 cm
 (Rise in cm) + (Going in cm) = 40 to 45 cm
 (Rise in mm) + (Going in mm) = 400 to 450 mm

52.  Other combinations of rise and going can be calculated
by subtracting 20 mm from going and adding 10 mm to
rise. Thus other combinations of rise and going would
be
 Rise 15 cm x Tread 28 cm
 Rise 16 cm x Tread 26 cm
 Rise 17 cm x Tread 24 cm

53.  Generally adopted sizes of steps are:
 Public buildings: (27 cm x 15 cm) to (30 x 14 cm)
 Residential buildings: 25 cm x 16 cm
 Standard sizes of steps are:
 Riser = 150 mm
 Trade = 300 mm

54. Le
LANDING
WAIST SLAB
Case (a)
WALL
Effective Span For
Longitudinally Spanning
Staircases
Waist Slab Supported at
the Ends of Landings

55. X X Y Y
Le
Case (c)
Case (b)
Le
Le=G +[ X +Y], X ≤1m AND Y ≤1m
Le=c/c of beams
GOING=G
Effective Span For
Longitudinally
Spanning Staircases

56.  Steel at bottom longitudinally-tension
 Anchorage and development steel
 Distribution steel
 Nominal foundation for ground flight

57.  A dog legged stair case is to be detailed with the
following particulars:
 Clear dimension of stair case room = 4.48 m x 2.1 m
 The floor to floor height is 3.2 m
 Width of each tread = 250 mm
 Width of each rise = 160 mm
 Thickness of waist slab = 150 mm
 Width of flight = 1m
 All round wall = 230 mm

58.  Both flights are supported at the ends of
 landing on 230 mm wall.
 (Landing and flight spans in the same direction)
 The first flight starts from the plinth level
 Main steel for each flight = #12@120
 Distribution steel for each flight = #8@ 200
 Use M20 concrete and Fe 415 steel.

59.  Draw to a suitable scale
 The plan of stair case
 Sectional elevation of the Ground flight
 Sectional elevation of the First flight

60.  Dimensioning:
R = 160 mm
T = 250 mm
 Floor to floor height = 3200 mm
 No of rises = 3200/R
= 20. (Each flight has 10 rises)
 No of treads per flight = 10 - 1
= 9

61.  Width of landing along flight
= {4480 – (9 x 250)}/2
= 1115mm.
 Going of flight = 9 x 250
= 2250mm
 Development length = 47φ
= 47 x 12
= 564 mm

62. Gap=0.1m
PLAN
1115 mm 1115 mm2250 mm
Le = 4710 mm
2100