staircases
TRANSCRIPT
Staircase
Types & design consideration
The longest staircase in the world
is located at the Niesenbahn railway
in Switzerland. It contains 11,674 steps
and spans a height of 5,476 feet.
• Function
• Considerations for
design
• Types
• Materials
• parts of a stairway
/staircase
• Construction
details
Function
• To ascend or descend levels
• To maintain connectivity between spaces
• To be aesthetically appealing
• To maintain visual control / privacy
• To maximize efficiency
• To allow easy access between levels
A staircase is a structure built , installed or erected for the main
purpose of ascending or descending levels within a building / structure,
Or without ; such as terraces, pavilions , buildings ,trees, hills etc.
Intended
use:-
Where ?
What ?
For whom? Private use Public use
Buildings :
General or special use
Transit facilities/
Temporary facilities
Exterior
Young / old /people
with disabilities
Or special needs /
general
Residence , offices
Which type?
Single users
Or masses
Which type?
Hospitals/ stations
Play equipment,
parks
Which type?
Suitability & design
indicators Spatial requisites :
Sizes, heights etc.
Materials
Where to be located?
L-shaped, spiral
Which type?
Appearance
Other uses
Safety & Method
who???
Types
As per material:
Wood
Metal
Stone
Brick
Concrete
Glass
As per layout / form:
L- shaped
Doglegged
Bifurcated
Spiral
Circular / geometric
Straight
As per landing & step type:
Open newel/ open well
Newel
Quarter turn
Half landing
U – turn
Winders / winding
composites
As per
importance & location:
Fire escapes
Service staircase
Grand staircase
External staircase
Internal staircase
As per
Method of construction:
Prefabricated
Cast-in-situ
Floating
Suspended
Types : I
Types : eg.
Type : II
As per material
concrete
Stone
Glass
Wood
Composites
Brick
Floating / open riser staircase
Suspended staircase
& prefabricated
Type :III & IV
Components and terminology
Stairway
– This term is often reserved for the entire stairwell and staircase in combination; though often it is used interchangeably with "stairs" and "staircase". This term is often reserved for the stairs themselves: the steps, railings and landings; though often it is used interchangeably with "stairs" and "stairway". In the UK, however, the term "staircase" denotes what in the U.S. is called "stairway", but usually includes the casing – the walls, bannisters and underside of the stairs or roof above.
Staircase: – This comprises the whole of
the stair construction and is the name given to the space or enclosure which contains the stairs.
• Step : The step is composed of the tread and riser / the tread and riser combined
• Tread : The top or horizontal surface of a step The part of the stairway that is stepped on. The tread "depth" is measured from the outer edge of the step to the vertical "riser" between steps. The "width" is measured from one side to the other.
• Riser : The vertical portion between each tread on the stair. This may be missing for an "open" stair effect.
or
the board that forms the face of the step..
• Starting step or Bullnose step :
Where stairs are open on one or both sides, the first step above the lower floor may be wider than the other steps and rounded
or
It is usually at the bottom of the stairs with one or both ends of the step having a quarter circle design.
Curtail Step - a decorative shaped step at the bottom of the stairs usually accommodating the volute and volute newel turning of the Continuous Handrail System.
• Nosing: Nosing - the edge of the tread projecting beyond the face of the riser and the face of a cut string. or
An edge part of the tread that protrudes over the riser beneath. If it is present, this means that horizontally, the total "run" length of the stairs is not simply the sum of the tread lengths, the treads actually overlap each other slightly
• , Stringer board or sometimes just String
– The structural member that supports the treads and risers. There are typically two stringers, one on either side of the stairs; though the treads may be supported many other ways. The stringers are sometimes notched so that the risers and treads fit into them. Stringers on open-sided stairs are often open themselves so that the treads are visible from the side. Such stringers are called "cut" stringers. Stringers on a closed side of the stairs are closed, with the support for the treads routed into the stringer.
• Winder:
This is an angular-shaped step
– Winders are steps that are narrower on one side than the other. They are used to change the direction of the stairs without landings. A series of winders form a circular or spiral stairway. When three steps are used to turn a 90° corner, the middle step is called a kite winder as a kite-shaped quadrilateral.
or
are radiating steps narrower at one end that are used to change the direction of a stairs through 90° or 180°
• Going / Run - the going of a flight of stairs is the horizontal distance between the face of the first and last risers. The individual going of a step is measured from face of riser to face of riser and for domestic use should be a minimum of 220mm.
• Rise - the rise of a flight is the vertical distance between the floors or landings connected by the flight. The individual rise is the vertical measurement from top of tread to top of tread.
• Trim – Trim (e.g. quarter-round or
baseboard trim) is normally applied where walls meet floors and often underneath treads to hide the reveal where the tread and riser meet. Shoe moulding may be used between where the lower floor and the first riser meet. Trimming a starting step is a special challenge as the last riser above the lower floor is rounded. Flexible, plastic trim is available for this purpose, however wooden mouldings are still used and are either cut from a single piece of rounded wood, or bent with laminations is concave moulding that is underneath the nosing between the riser and the tread above it.
The Railing system types • Handrails may be continuous (sometimes called over-the-post) or post-to-post (or more
accurately "newel-to-newel"). For continuous handrails on long balconies, there may be multiple newels and tandem caps to cover the newels. At corners, there are quarter-turn caps. For post-to-post systems, the newels project above the handrails.
• Another, more classical, form of handrailing which is still in use is the tangent method. A variant of the Cylindric method of layout, it allows for continuous climbing and twisting rails and Easings. It was defined from principles set down by architect Peter Nicholson in the 18th century.
The railing system terms • Balustrade : The balustrade is the
system of railings and balusters that prevents people from falling over the edge.
or
the collective name for the complete assembly of handrails, baserails, newels, spindles and caps.
• Banister, Railing or Handrail : – The angled member for handholding,
as distinguished from the vertical balusters which hold it up for stairs that are open on one side; there is often a railing on both sides, sometimes only on one side or not at all, on wide staircases there is sometimes also one in the middle, or even more. The term "banister" is sometimes used to mean just the handrail, or sometimes the handrail and the balusters or sometimes just the balusters
• Flight :
– A flight is an uninterrupted series of steps / a continuous series of steps between two landings.
• Floating stairs :
– A flight of stairs is said to be "floating" if there is nothing underneath. The risers are typically missing as well to emphasize the open effect. There may be only one stringer or the stringers otherwise minimized. Where building codes allow, there may not even be handrails.
Baluster
A term for the vertical posts that hold up the handrail. Sometimes simply called guards or spindles. Treads often require two balusters. The second baluster is closer to the riser and is taller than the first. The extra height in the second baluster is typically in the middle between decorative elements on the baluster. That way the bottom decorative elements are aligned with the tread and the top elements are aligned with the railing angle.
or
Baluster/Spindle - the vertical member, plain or decorative, that acts as the infill between the handrail and baserail (or tread if cut string).
• Newel – A large baluster or post used
to anchor the handrail. Since it is a structural element, it extends below the floor and subfloor to the bottom of the floor joists and is bolted right to the floor joist. A half-newel may be used where a railing ends in the wall. Visually, it looks like half the newel is embedded in the wall. For open landings, a newel may extend below the landing for a decorative newel drop.
• Landing or Platform – A landing is the area of a floor near the top
or bottom step of a stair. An intermediate landing is a small platform that is built as part of the stair between main floor levels and is typically used to allow stairs to change directions, or to allow the user a rest. As intermediate landings consume floor space they can be expensive to build. However, changing the direction of the stairs allows stairs to fit where they would not otherwise, or provides privacy to the upper level as visitors downstairs cannot simply look up the stairs to the upper level due to the change in direction.
or
A platform forming a kind of halting-place between two flights of stairs.
A quarter-space landing forms a
space, usually a rectangle, equal in
width an length to the breadth of the two
flights which it separates.
A half-space landing extends the
total width of the staircase.
Other terminology
Balcony
– For stairs with an open concept upper floor or landing, the upper floor is functionally a balcony. For a straight flight of stairs, the balcony may be long enough to require multiple newels to support the length of railing
Volute
– A handrail end element for the bullnose step that curves inward like a spiral. A volute is said to be right or left-handed depending on which side of the stairs the handrail is as one faces up the stairs
• Pitch - the angle between the pitch line and the horizontal. Pitch Line - the notional line connecting the nosings of all treads in a flight of stairs.
or
The pitch line is the imaginary line along the tip of the nosing of the treads. Rake - the pitch of the stairs.
String Margin - the distance between the top of the string and the pitch line measured at 90° to the pitch line.
• Runner – Carpeting that runs down
the middle of the stairs. Runners may be directly stapled or nailed to the stairs, or may be secured by specialized bar that holds the carpet in place where the tread meets the riser.
• Spandrel – If there is not another flight
of stairs immediately underneath, the triangular space underneath the stairs is called a "spandrel". It is frequently used as a closet.
• .
Well-hole : the open
space enclosed by the stairs.
Stairwell :The space/void provided for the stairs
• Soffit
-The underside of a structural component, such as a beam, arch, staircase, or cornice
• Headroom is the height above the nosing of a tread to the ceiling above it.
Core-rail
An iron band is frequently
used in geometrical
stairs to give extra strength
and stiffness
to the handrail. It is generally
about 4 in. thick,
being screwed into a groove
formed in the
underside of the handrail. It is
especially
necessary for the curved
portions of the
handrail, where the grain of
the wood is often cut across
Wall String - the string of a staircase fixed flush with a wall. Closed String - a string with the face housed/trenched to accommodate treads and risers so their profile cannot be seen. Cut or Open String - a string with the upper edge cut away to the shape of the treads and risers so that their profile can be seen from the side. Continuous Handrail - using straight lengths of handrail connected to handrail fittings and ramps, the handrail flows over the tops of newel turnings creating a continuous run of handrail.
• Baserail or Shoerail
– For systems where the baluster does not start at the treads, they go to a baserail. This allows for identical balusters, avoiding the second baluster problem.
• Fillet
– A decorative filler piece on the floor between balusters on a balcony railing.
• Turnout – Instead of a complete spiral
volute, a turnout is a quarter-turn rounded end to the handrail.
• Gooseneck – The vertical handrail that joins a
sloped handrail to a higher handrail on the balcony or landing is a gooseneck.
• Rosette – Where the handrail ends in the
wall and a half-newel is not used, it may be trimmed by a rosette.
• Easings
– Wall handrails are mounted
directly onto the wall with
wall brackets. At the bottom
of the stairs such railings
flare to a horizontal railing
and this horizontal portion
is called a "starting easing".
At the top of the stairs, the
horizontal portion of the
railing is called a "over
easing".
• The rise height or rise of each step is measured from the top of one tread to the next. It is not the physical height of the riser; the latter excludes the thickness of the tread. A person using the stairs would move this distance vertically for each step they take.
• The tread depth is measured from the edge of the nosing to the vertical riser.
&
The going is measured from the edge of the nosing to the edge of nosing in plan view. A person using the stairs would move this distance forward with each step they take & it
should be 220mm for a domestic use.
• The total run or total going of the stairs is the horizontal distance from the first riser to the last riser. It is often not simply the sum of the individual tread lengths due to the nosing overlapping between treads.
Stair Measurements
• The total rise of the stairs is the height between floors (or landings) that the flight of stairs is spanning. To avoid confusion, the number of steps in a set of stairs is always the number of risers, not the number of treads
• The slope or pitch of the stairs is the total rise divided by the total run (not the individual riser and treads due to the nosing). It is sometimes called the rake of the stairs. In the UK, stair pitch is measured in degrees from the horizontal.
• The maximum individual rise for domestic flights is 220mm
Rise
Run
• Landing width:
- Should be 90- 100 cm for domestic
use & as per building codes
for other buildings types.
• Walkline – for curved stairs, the
inner radius of the curve may result
in very narrow treads. The "walkline"
is the imaginary line some distance
away from the inner edge on which
people are expected to walk. Building
code will specify the distance.
Building codes will then specify the
minimum tread size at the walkline.
• No. of Treads = the span or going
divided by
the width of one tread
• No. of Risers = the total height to be
ascended divided by the height of
one riser
Ergonomics and building code
requirements
• Ergonomically and for
safety reasons, stairs
have to have certain
measurements in order
for people to comfortably
use them. Building codes
will typically specify
certain measurements so
that the stairs are not too
steep or narrow.
Staircase Detailing:
Cross sections
of railings
Joint between stringer & newel post
Moulding details for Easings
Joints of floor finish, studs with
joists
Marking & Fitting :
Plan & elevation
of dog legged
stair A half-turn stair which has no
wellhole between successive flights; the rail and balusters of the upper and under flights fall in the same vertical plane.
Advantages :
• To allow an arrangement that occupies a shorter, though wider, floor area . more compact
• The upper floor is not directly visible from the bottom of the stairs, thereby providing more privacy .
• An object or person falling from the upper half of the stairs is likely to stop at the landing; this is safer
L – shaped stair
Quarter turn staircase
Metal circular stair details
Glass staircase
Plywood staircase
Concrete staircase
Stone
staircase
brick stairs construction details
Staircase
concepts
Grandiose
Storage ideas &
Space savers
Hidden
Focal points
Decorative
Fantastic
The grandiose / the mega scale:
The fantastic :
Other
mechanisms for
level change
Stairlifts
Lifts / Elevators
ramps
Escalators
• A wheelchair stair lift is a device that allows a wheelchair user to ride up or down a flight of stairs unaided. It incorporates a platform that enables a wheelchair to be wheeled straight on, then locked in place to prevent it moving
• The user remains seated in the wheelchair during the ride up or down and the unit is driven by an electric motor. It runs along a track or ramp fitted to the stair risers themselves.
• An escalator is a moving staircase – a conveyor transport device for carrying people between floors of a building. The device consists of a motor-driven chain of individual, linked steps that move up or down on tracks, allowing the step treads to remain horizontal. Escalators are used around the world to move pedestrian traffic in places where elevators would be impractical areas of usage include department stores, shopping malls, airports, transit systems, convention centers, hotels, and public buildings.
• An elevator (or lift in British English) is a vertical transport equipment that efficiently moves people or goods between floors (levels, decks) of a building, vessel or other structure. Elevators are generally powered by electric motors that either drive traction cables and counterweight systems like a hoist, or pump hydraulic fluid to raise a cylindrical piston like a jack.
Thank you