There are some principles to be
observed while designing a staircase for homes as listed below.
A- Step Proportioning.
The riser and tread of every step
should be of regular dimensions throughout the length of the stair. The
proportion between going and rise of stop should be carefully worked out so as to
provide comfort and ease to the users.
The following rules should be
followed for finding a suitable relation between going and rise of steps in
stair.
1) Rise + Going = 400 to 450 mm.
2)
(2x Rise) + (Going) in mm = 550 to 600 mm
3) Going x Rise, both in mm = 40000
to 41000 Sq.mm
while designing steps ,take 300 mm
going and 140 mm rise as a standard value. For every 20 mm deduction from tread
,add 10 mm to the rise.
The following dimensions of tread
and rise are generally used for different buildings
1) Residential buildings 250x160 mm.
2) Public buildings such as theatres
,colleges, banks etc.
3) Industrial Buildings ,The tread
should not less than 250mm and rise not more than 190 mm.
It should be noted that the rules
given above only act as guide but the actual dimensions of tread and rise
depend upon the space available height of building and layout of stair.
B- Pitch of stair
The pitch or slope of the stair
should neither be more than 40 degree nor less than 25 degree for at ease
ascend and descend by the users.
C- Width of the stair
The width of the stair should be
such that a person going up can pass a person coming down without any
difficulty. The minimum width of stair in a residential building should be 1
Meter whereas in case of public building a minimum width of 1.5 Meter is
desirable.
D- Length of flight
The number of steps in a flight
should not be more than 12 otherwise it becomes difficult to move up and down the
flight and the minimum number in a flight should be 3.
E-Head Room
An sufficient head room must be
provided .It should not be less than 2.14 m vertically or 1.5 m at right angles
to the line of nosing.
F- Winders
They should be avoided as for as
possible because they are liable to be dangerous and involve extra expenditure
in construction. Winders are difficult to be carpeted and are especially
unsuitable for public buildings. However, they are to be provided when the area of the
staircase is limited, In such cases , winders should be placed at the lower end
of the flight.
In a quarter space ,i.e. 90 degree
turn ,only three winders should be provided.
G- Hand rails and balustrades.
A staircase should be provided with
a hand rail along with balustrade to provide assistance ,comfort and safety to
the users. The height of hand rail should neither be more than 0.85 meter and
nor less than 0.75 meter.
H-Materials of stair
The stair should be constructed of
sound materials of fire resisting
quality. It should preferably be constructed of R.C.C according to building
bye-laws being followed in locality.
I- Location of stair
The staircase should be located in
such a position that it can be easily and speedily approachable. It should be
provided in center of the building where enough light and ventilation is
ensured specially at turning points in a staircase.
In residential building stair should
be located near the main entrance and screened from outside for privacy. In
public building it should preferably be located obvious from the main entrance.
