2. Stair
2
OVERVIEW
• Introduction
• Functional requirements
• Basic elements of stairs
• Type of stairs
3. Stair
3
INTRODUCTION
What is vertical movement or vertical circulation?
• Circulation is a movement of human and goods between
interior spaces in the building to the entrance or exit.
• Can be channeled through several types – passageway,
corridor, stairs, ramps, etc.
• Vertical circulation is movement of human and goods
between stories of a building.
• Classified into 2 classes;
• Class 1 system – ramps, staircase, elevators, escalators.
• Class 2 system – mainly not for human, e.g. dumbwaiters.
5. Stair
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INTRODUCTION (cont.)
STAIRS/STAIRWAY
• A set of steps formed to make it possible to pass to another
level on foot by putting one foot after the other on alternate
steps to climb up or down the stair.
• Stairs can be made of concrete, stone, wood, steel or
combination of any of these.
6. Stair
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INTRODUCTION (cont.)
LADDER
• A series of narrow horizontal steps fixed between two upright of
wood or metal, on which a person usually climbs up or climbs
down facing the ladder.
• Usually fixed in an upright, near vertical position or more at a
shallow slope for ease of use. Therefore, it only occupy the least
floor area.
• Not suitable for elderly and handicapped and as a mean of
escape in case of fire.
• Should only be used for access to loft conversion of one room,
where there is not enough space for a stair, and that should be
fixed in position and fitted with handrails both sides.
7. Stair
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INTRODUCTION (cont.)
STEPLADDER
• A series of comparatively narrow, flat, horizontal steps, fixed
between two vertical upright, which provide more comfortable
and secure support for the foot than the slim.
RAMP
• A ramp is a surface, sloping uniformly as an inclined plane up
and down which a person may pass on foot between levels.
• Formed at a slope of at least 1:20. Thus, it occupies a
considerable area, usually adjacent to a long, low building.
8. Stair
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FUNCTIONAL REQUIREMENTS
STRENGHT
• Able to support for movement between floors, including dead
and imposed load.
SAFETY IN USE
• Comply with the Building Regulation in determining the rise,
thread, headroom and dimensions of the handrails and guarding.
• Should be constructed of materials that are capable of
maintaining strength and stability for a period of time sufficient to
escape to the outside.
FIRE SAFETY
• The steps and the width should be adequate for the safe escape
to the outside.
9. Stair
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PRIMARY FUNCTIONS
• Provide an access from one floor to another.
• Provide a safe means of travel between floors.
• Provide a degree of insulation where part of a separating
element between compartments in a building.
• Provide an easy mean of travel between floors.
• Provide a suitable means of escape in case of fire.
• Provide a mean of conveying fittings and furniture between
floor levels.
11. Stair
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STAIR TERMINALOGY
STEPS
• A series of horizontal open
treads with a space between
the treads with a space
between the treads or as
enclosed steps with a vertical
face between the treads.
• Tread – horizontal surface
of a step
• Riser – vertical surface or
near vertical of a step
12. Stair
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STAIR TERMINALOGY (cont.)
FLIGHT
• Uninterrupted series of steps between floor and landing, or
between landing and landing.
• A flight should have no fewer than 3 steps and no more than
16 risers.
• The rise and tread in one flight and landings between floors
should be equal.
• The rise and tread should have the same size to avoid
interruption in the rhythm of going up or down.
• The dimension of the riser and thread will determine whether
the stair is steep or shallow.
13. Stair
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STAIR TERMINALOGY (cont.)
FLIGHT (cont.)
• The dimensions will depends on the
function of the building and should
comply with the Building Regulation
(UBBL), e.g. Section 40.
• The steeper stair will save more space
and is accepted for houses because
the occupants are more familiar with
the stair.
• The shallow stair requires more area but
suitable for public building to minimise
danger to the public escaping via stair
during emergency.
14. Stair
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STAIR TERMINALOGY (cont.)
HEAD ROOM
• A clearance height
between the pitch line of
the stair and the underside
of the stairs, landings and
floors above the stair.
• Minimum 2 m clearance
from the pitch line for a
convenience of human
and goods movement.
15. Stair
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STAIR TERMINALOGY (cont.)
Baluster
• Vertical stand that supports
handrails for security purposes.
• Can be made from timber or
steel.
• Can be bolted to the sides of
flights or through the material,
grouted or set in mortices
either cast or cut in the
material.
Handrail
• Horizontal member fixed on the
top of series of balusters.
• Can be made from timber or
steel.
Balustrade
• A series of baluster, capped by a handrail.
17. Stair
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TYPE OF STAIRS
• Type of stairs:
o Straight flight/straight run
o Quarter turn/L-shaped
o Half turn (dog leg)/180 return
o Spiral (helical) & elliptical
o Winder
18. Stair
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TYPE OF STAIRS
Straight Flight Stair
• Rises from the floor to floor in
one direction with or without
an intermediate landing.
• Known as ‘cottage stair’ as
well, commonly used in the
traditional ‘two-up two-down’
cottage.
• The most economical use of
the straight flight is to locate
the stair in the centre of the
plan running for front to back.
19. Stair
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TYPE OF STAIRS (cont.)
Quarter Turn Stair/
L-shaped
• Rises to a landing between
two floors, turns through 90˚,
then rises to the floor above.
• Good in compact planning.
• The quarter turn sometime
will be replaced with winders
for economic use of space.
20. Stair
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Half Turn (Dog Leg) Stair
• Rises to a landing between floors,
turns through 180˚, then rises
parallel to the lower flight to the
floor above.
• The most common arrangement
of stairs.
• Advantage – can be
constructed within the confined
vertical stair well.
21. Stair
21
Spiral & Elliptical Stair
• Constructed as either a
spiral(helical) stair or an ellipse
stair.
• The most economical way to
save space, but difficult to
use due to the sharp turns.
Very dangerous for the very
young and elderly.
• Usually use where the space is
very limited for access to an
intermediate floor of one
room.
Spiral (helical) stair
Elliptical stair
22. TYPE OF STAIRS (cont.)
Winder Stair
• Triangular treads/tapered treads that
wind around quarter of half turn in place
of landings.
• To reduce the number of steps required
in the rest of the stair and to economise
in space.
• Usually use in domestic stairs.
• Can be hazardous as they only offer little
foothold at the interior corner.
• Not recommended for public buildings in
the means of escape stairs especially for
the very young and elders.
23. Stairs can be made of :
• Timber
• Concrete – precast & cast-insitu
• Metal
• Stone
24. Timber Staircase
• Constructed from timber board
• Common use in domestic work.
• The design of stairs flight landings or tapered steps is
depend on the space to accommodate it.
• Handrail balustrading is important to provide visual and
practical safety barrier to the side of stairs.
26. Stair
26
Timber Stair (cont.)
Tapered stairs/winder
• Frequently used because
can use space
economically
Open tread stairs
• Closed string
• Cut strings or carriages
• Mono-carriage
• Alternating tread stairs
29. Alternating trade stairs
• Application – access to domestic loft
conversion only
• Very steep pitch – very economic
use of space
• Not very safe.
30. Reinforced Concrete Staircase
• Can be cast in-situ, precast or combination of both.
• Better fire resistant from timber staircase.
• Common use in multi-storey building.
• Can be formed as straight flight, quarter turn, half turn or
geometrical. But, the usual form is half-turn.
• The construction of the staircase depends on the structural
of the building and the convenience in casting the stairs in
situ or the use of reinforced concrete support and precast
steps.
31. TYPE OF STAIR (cont.)
In-situ RC stair
• Variety of stair types and arrangements are possible, which of
having its own appearance , characteristic and method of
construction.
• Common use as it is non-combustible, stronger and
hardwearing.
• Will maintain its strength and integrity for a reasonable period
during an outbreak of fire. Therefore, it is more suitable than
timber stair as an escape route.
• Typical in-situ RC stairs are:
o Inclined slab stair
o Cranked slab stair
o String beam stair
o Cantilever stair
32. TYPE OF STAIR (cont.)
Inclined slab stair
• Constructed when there are
LB wall around the stair.
• The landing is built into the
walls as one way span slab.
• The flight span from floor to
landing and landing to floor.
• Disadvantage – wasteful
cutting of brick or block to
allow the flight built into the
walls.
33. TYPE OF STAIR (cont.)
Cranked slab stair
• The stair is constructed as a
cranked (bent) slab spanning
from landing to flight and to
landing with no side supports.
• This type of construction only
use when the landings can
not gain support each side of
stair.
• Disadvantage – more costly
34. TYPE OF STAIR (cont.)
String and trimmer stair/String beam stair
• The landing beams are
supported by side walls (LB) or
the beams of the frame and
in turn support inclined beams
that support the flight.
• Disadvantages - cause untidy
soffit or underside of the stair.
• Best suited for to the use of
precast concrete steps and
precast landing.
35. TYPE OF STAIR (cont.)
Cantilevered stair/cantilevered spine wall
• Constructed to cantilever
from the spine wall, or can
be partly cantilever from the
spine wall and supported by
the enclosing frame or walls.
36. TYPE OF STAIR (cont.)
Precast Concrete Stair
• Can be produced to most of the formats used for insitu RC stair.
• Seldom used because of the majority using cast in-situ method.
Common use for aesthetic reason.
• Advantages –
o good quality control of finished product
o no formwork thus no storage required and save the
site space
o stair can be installed at any time, thus the stair shaft can
be used for other purposes e.g. for lifting or hoisting space
o Hoisting, positioning and fixing of stair can be carried out by
semi-skilled worker.
37. TYPE OF STAIR (cont.)
Stone Stair
• Traditionally constructed using natural stone as the steps.
• Can be formed as:
o Rectangular/stepped soffit
o Flush soffit
• The end of the steps are built into the walls. The landings are
constructed using one or more large slab of natural stone built
into enclosing walls and bearing on the steps below.
38. TYPE OF STAIR (cont.)
Stone Stair (cont.)
Stone steps with stepped soffit Stone steps with flush soffit
39. Metal Stair
• Can be produced in cast iron, mild steel or aluminium alloy for
both external and internal used.
• Usually is custom made, therefore is more expensive.
• Steel channel section serves as stringer.
• Treads can be in the form of steel pan filled with concrete,
steel flat plate with textured top surface or bar grating.
• Can be painted or covered with concrete for fire safety
reason.
• Advantage – no need formwork during construction.
• Disadvantage – regular maintenance in the form of painting.
46. REFERENCES
1) R.Barry,1992, The Construction of Building,Vol. 2, 5th ed,
Blackwell Science Ltd.
2) Frederick S. Merritt et. al, 2001. Building Design and
Construction Handbook, 6th ed., McGraw Hill.
3) Roy Chudley, et.al, 2005.Building Construction Handbook
,5th ed, Elsevier.
4) Francis D.K.Ching, 1991, Building Construction Illustrated,
2nd ed.,Van Nostrand Reinhold.
