1. BUILDING CONSTRUCTION

2. STAIRS AND STAIRCASES
Stairs : “It’s a series of steps suitably arranged for the purpose of connecting different floors of the building.”
General specification about stairs
Should be locate at centre of building geometry
Should be near to the entrance
Sufficient amount of stairs incase of huge geometry
Location such that ease to reach and at lesser time from any part of the building
Material used in stairs must be fire resistive and non corrosive
Staircases : “ enclosure of the building in which stair is located”

3. Technical terms of stairs their specifications:

4. Technical terms of stairs:
Step: a single unit composed of Rise and Tread
Tread: Upper flat portion of step upon which the foot is placed for ascending or descending
Riser: vertical portion of step providing support to the tread
Rise: the vertical distance between two successive tread facing
Going: horizontal distance between two successive riser faces
Baluster: vertical member of wood or metal, supporting the hand rail
Balustrade: combine frame work of railing and baluster , used to provide protection to the user
Hand rail: molded member of wood or metal, used to providing assistance and safeguard to person while going over stair
Flight: a series of steps without an intermediate platform
Landing: flat platform at the top and bottom of the flight , used to change direction and for taking rest

5. Technical terms of stairs:
Nosing: protecting edge of tread
Pitch or slope: An angle which the line of nosing made with floor
String: these are the sloping members which support the steps
Scotia: A molding provided under the nosing to improve the elevation of the step, and provide strength to nosing
Waist: thickness of structural slab in case of stair made up of R.C.C
Newel post: These are principal posts supporting a hand rail, placed at the ends of flights to connect the ends of strings and hand rail.
Head room: minimum clear vertical distance between the tread and over head structure i.e. ceiling etc.
Run: total length of stair in a horizontal plane, including landings
Header: horizontal structural member supporting stair strings or landings.

6. Figure: Flight and Head room of stair
Technical terms of stairs their specifications:
Figure: Flight and Head room of stair

7. Technical terms of stairs their specifications:
Figure:

8. Technical terms of stairs their specifications:
Figure: Flight should be divide if its width more than 1.8 m

9. Requirement of good stairs:
Location:
Sufficient light and ventilation should be available
Should be Easy to access
Should be located centrally on building geometry
Material: Good quality (Strength, Fire resistance) and should be constructed with good workmanship
Width of Stair: Should be sufficient width and at least 1m in residential building and more than one meter in case of public building
Length of flight: Not more than 12 steps and not less than 3 steps in single flight
Pitch of stair: Should not more inclined
Head room: should not less than 2 to 2.3m
Step Dimension:
Going or tread : should not less than 25cm
Rise: should not more than 15cm
The width of landing should not be less than the width of stair.

10. Types of Steps in stair:
Flier: Ordinary rectangular step
Bullnose : Situated at the bottom of flight and having one or both end of step rounded
Round ended: same as bullnose but the top view is semicircular
Splayed step: Provided at the beginning step with tapered face
Commode Step: Curved riser and tread
Dancing step: Horizontally inclined step
Winders: Tapering step, usually provided when less space availability, Winders should be avoid in public building

11. Types of Steps in stair:

13. Classification of Stairs
Straight stair: Having one single flight or numbers of straight flights
Turning stair:
Turning stair further classified as
Quarter turn stair:
Newel Quarter turn
Geometrical quarter
Half turn stair:
Dog-legged or Newel Half turn
Open newel half turn
Geometrical half turn
Three quarter turn stair
Bifurcated stair
Spiral stair
Helical Stair

14. Types of Stair : Straight Stair
Straight Stair: Plan
Straight between two floors
Continuous in one direction
Single or may be more than one
Used for Small houses where narrow space is available.

16. Types of Stair : Newel Quarter Turn Stair
It is used when the direction of flight is changed at right angles to the left or right.
Plan
Sectional Elevation
Newel Quarter Turn Stair
Newel post at the beginning and at the End of each flight
The quarter turn may be of winders or space landing

18. Types of Stair : Geometrical Quarter Turn Stair
Commonly provided at the backside of the building for providing entry at various floors.
Plan
Geometrical Quarter Turn Stair
Strings as well as hand rail is continuous
No newel post at the Landing
Having circular shape in plan.

20. Types of Stair : Dog-Legged Stair Quarter space landing
It is used when length of staircase is restricted and width is such that only two flight is accommodated
Dog-Legged Stair Quarter space landing: plan
Consists of two Straight flight of steps with abrupt turn between them
The direction of the flight is turned by 180’
There is no space between two flights.

22. Types of Stair : Open Newel Half Turn Stair
Plan
Open Newel Half Turn Stair: plan
This type of stairs are used at places where sufficient space is available to accommodate a third flight having three to four steps.
Same as Dog-legged but its having space between two flights.

24. Types of Stair : Geometrical Half Turn Stair
Geometrical Half Turn Stair: plan
Continuous hand rail without any breakup
May have half space landing or without landing

25. Types of Stair : Bifurcated Stair
Bifurcated Stair: plan
Common in public building at their entrances hall.
Wide flight at the beginning and narrow flight when it turns in both the direction

27. Types of Stair : Spiral Stair
Top view circular with single centre of curvature
Generally made up of R.C.C or Steel
This type of stairs are used, where space available is to small and the traffic is less.
Also used as a emergency stairs and provided at the backside of the building.
Circular Stair: plan

29. Types of Stair : Helical Stair
This stair looks very fine.
The structural design and construction is very complicated.
It is made of RCC ,steel and wood.
Helical Stairs: plan

31. Fabricated Stair : Timber:
Used in residential buildings and at small shops
Light weight
Used when fire resistance criterion not important
Built on place or at shop
Timber used for stair should be free from termite, well treated
Metal
Mild steel or cast iron used
Used for factory, godowns, workshops
Not used for residential and public building
They creates noise
Not good appearance
Pre-Cast concrete:
Ready made cast available in market

32. Elevators or Lifts: “It is the Appliances designed to transport persons or materials between floors in vertical direction by means of guided vertically movable platform”
Two basic system :1) Counter weight suspension
2) Electrically motors
Types of Lifts:
Passenger lift:
For moving human being
Goods lift:
For material transport
Having loading and unloading facilities
Hydraulic Elevator or Lift
For Low rise buildings
Electric lift
For tall buildings

33. Design Criterion/Consideration for Lift
Numbers of lift block, its size, position in building geometry
Particulars of lift block enclosure
Lift door
Number of floors or vertical distance for lift
Height between floor levels
Total headroom
Numbers of entrance
Numbers of passengers to be handled
And of course the weight carrying capacity

34. Suitability of Types of Vertical Appliances GTU- June-2010
Dog-legged stair: When need to sudden change of direction while vertical movement of human Being
Elevators or Lift: More than four storey for moving people and materials
Ramps: when larger numbers of people or vehicle are to be moved from floor to floor e.g. Garage, railway station, stadium etc.
Escalators: Where traffic is heaviest and convenient for passengers when large numbers of persons to move from floor to floor,
Generally provided at shopping mall, public building etc for the architectural point of view
used to guide people towards main exits.
Also speed should be changed based on current of motors.
Inclination angle is 30 degrees.

36. Ex :- Plan of stair of building in which the vertical distance between the floors is 3.74 m. The stair hall measures 5.00*2.40 m .
Ans :- 1) take rise 17 cm and tread be 27 cm.
2) Let us keep width of each flight = 1.15 m
3) Width of landing = width of stair = 1.15 m
4) Height of each flight = 3.74/2 = m
5) No. of risers required = 1.87/17 = 11 in each flight
6) No. treads in each flight = 11-1 = 10
7) Space occupied in treads = 10*27 = 2.70
8) Space left for passage = 5.0 – 1.50 – 2.70
= 1.15 m ok

37. THANK YOU