2. EVOLUTION OF STAIRCASE
Staircase are one of the oldest building
elements in architectural histories….
Reflecting the prevailing philosophies and
symbolic language.
WHY DO WE NEED STAIRCASE
To protect people from injuries and to
facilitates access during movements from
one level to the another in a building.
LOCATION OF STAIR
Stair should be placed at a central place in the building so
as to give shortest access to all rooms. It should be well
ventilated and airy.
3. PRINCIPLES TO BE OBSERVED WHILE PLANNING AND DESIGNING A STAIR
1. Width of Stair: It should not be less than 1.00m.
2. Length of flight: The number of steps in a single flight should not be more than 12.
3. Pitch of the stair: It should be between 25 to 40
4. Width of landing: It should be 150mm, more than the width of stair.
5. Winders or kite steps: Odd shaped steps should be avoided and incase found
necessary. These should be provided at the start of a stair.
6. Han-rails: It should be 750 to 850 mm in height from the top of respective step or
landing.
7. Step proportions: The size of rise and tread in a stair should be kept uniform
through out the whole stair.
8. Headroom: Minimum of 2000mm of clear headroom is required above the pitch
line
Following proportions are recommended:
(i) Residential buildings- Tread=250 mm
Rise=160 mm
(ii) Public buildings - Tread=300 mm
Rise=150 mm
(iii) Industrial buildings, Railway station,
etc Tread =not less then 250 mm
=250 to 300 mm
Rise =not less then 150 mm
=150 to 190 mm
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4. Otherwise work out the sizes of rise and tread
by using any one of the following proportions
(i) (2xRise)+(Going), In mm=550 to 600 mm
(ii) Rise x tread, both in cm = 400 to 410 cm2.
(iii) With basic proportion of going 300 mm and rise 150 mm,
add 10 mm to rise for every 20 mm deduction from going e.g.
For a going of 280 mm the rise will be 160 mm.
The above rules act as guide but the actual sizes
depend upon the availability of space, while planning stairs
practical-field.
5.
6. Balusters
The smaller posts fitted between the stair and the handrail, usually
decorative, and in timber or steel.
Bullnose Step
The step at the base of a stair which usually has a protruding semi-
circular end
Capping
The piece of timber that forms the edge or border for the carpet or
other floor coverings, located at the edge of the floor on upper level
Closed Stair
A stair that has treads and risers
Cut Stringer
Stringers that are cut to follow the profile of the treads and risers.
Handrail
The shaped or moulded piece of timber you hold on to as you walk up
or down the stair.
Handrail Scroll
The decorative handrail piece at the start of the stair that curls around
and sits above the bullnose step
Handrail Wreaths
The sections that curve around corners to form a continuous handrail
Landing
The flat platforms usually located where a stair changes direction.
Newel Posts
The larger square posts at the start and the corners of a stair. They are
usually turned, fluted, panelled or decorated in some way.
7.
8. Open Stair
A stair that has no risers
Risers
The vertical pieces which are the solid infill between the
treads
Stringers
The main beams that support treads and risers
Tread Bracket
The decorative pieces that fit to the face of a cut stringer in
the more traditional type of stair
Tread Nose
The rounded leading edge of a step
Treads
These are simply the steps you walk on
Winder Steps
The triangular treads used to change the direction of the
stair, usually around right-angle corners
9. STAIR GEOMETRY
Stair safety and geometry are related- rhythmic
movement along a straight line is important for
safe ascent or descent
10. STAIR ANGLES
According to AS 1657-1992 (Fixed platforms,
walkways, stairways & ladders- Design, construction
& installation), stairways should be angled between
26.50 and 450- That’s between 1 in 2 and 1 in 1
Rise = 1
Going = 2
Rise = 1
Going = 1
26.50
450
11. Stairways landings must
be at least 30 inches
deep and 22 inches
wide at every 12 feet or
less of vertical rise
Unprotected sides of
landings must have
standard 42 inch
guardrail systems
Stairway Landings
Landing
12. Where doors or
gates open directly
on a stairway,
provide a platform
that extends at
least 20 inches
beyond the swing of
the door.
Platforms and Swing Doors
13. Straight flight stair
4.1 Stairways
>600mm between
handrails
4.1 Slope not less
than 26.50 & not
more than 450
STAIR TYPE 1
14. STAIR TYPE 2
Straight two-flight stair
with half-landing
4.2.1 stairs constructed
in flights straight or
curved horizontally
4.2.2 Number of rises
not to exceed 18 in a
flight; not more than 36
rises without a change
in direction
15. STAIR TYPE 3
Quarter-turn stair
with landing
4.3.1 All treads to be
slip resistant, with
provision made for
drainage
4.3.1 (a) Rises &
goings (in the same
flight) to be within
5mm
16. STAIR TYPE 4
Dogleg stair with
half-landing
4.3.2 Head clearance
min 2000mm
vertically from nosing
of tread
4.3.3 Nosing of tread
must be highlighted
17. STAIR TYPE 5
Open-well stair with
two quarter landings
4.3.1 (b) Each rise not
less than 150mm &
not more than 215mm
4.3.1 (c) Each going
not less than 215mm
& not more than
305mm
18. STAIR TYPE 6
Quarter-turn stair with winders
4.4 Landings:
(a) Length & width must
be not less than the
stairway
(b) Landing minimum
vertical clearance
2000mm
(c) Every access landing-
standing space at least
600mm clear of cross-
traffic or door swing
19. STAIR TYPE 7
Spiral stair with
central column
4.2.3 Radius to
centre line of
stairway not less
than 600mm; where
radius to centre line
is less than 3000mm,
maximum width of
curved stairway
750mm
20. Circular stair with
central well
4.3.1 (c) Each
Going not less
than 215mm & not
more than 305mm
STAIR TYPE 8
21. Geometric stair (900)
turn
4.3.1 (d) 45 000< RxG
<48 000
4.3.1 (e) Tread width
must not be less than the
going and there must be
an overhang of at least
10mm
STAIR TYPE 9
