Basic Introduction of Stairs….

Introduction

  • Staircase is an important component of a building providing access to different floors and roof of the building. It consists of a flight of steps and one or more intermediate landing slabs between the floor levels.
  • Stairs can be defined as series of steps suitably arranged for the purpose of connecting different floors of a building. It may also be defined as an arrangement of treads, risers, stringers, newel post, hand rails, and baluster, so designed and constructed as to provide an easy and quick access to the different floors.
  • A set of steps formed to make it possible to pass to another level on foot by putting one foot after the other an alternate steps to climb up or down the stair.
  • Stairs can be made of concrete, stone, wood, steel or combination of any of these.

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 a suitable means of escape in case of fire.
  • Provide a mean of conveying fittings and furniture between floor levels.

Why we need stairs?

  • To protect people from injury and to facilitate access during movement from one level to another in a building.

Parts of Stairs

  • Step: It is a portion of stairs which permits ascent & descent.
  • Tread: It is the upper horizontal portion of step upon which the feet is placed.
  • Riser: The vertical portion between each tread on the stair.
  • Handrail: A handrail is a rail that is designed to be grasped by the hand so as to provide stability or support.
  • Baluster: It is vertical member of wood or metal supporting the handrail.
  • Newel Post: This is the vertical member which is placed at the ends of flights to connect handrail.
  • Run: It is the total length of stairs in a horizontal plane, including landings.
  • Nosing: It is the projecting part of the tread beyond the face of the riser. It is rounded to give good architectural effect.
  • String or Stingers: These are the sloping wooden members which support the steps in a stair. They run along the slope of the stair.

Types of Stairs

  1. Straight Stair
  2. Dog Legged Stair
  3. Quarter Turn Stair
  4. Open Newel Stair
  5. Three Quarter Turn Stair
  6. Bifurcated Stair
  7. Geometrical Stair
  8. Circular Stair

Straight Stair

  • Stair may have one flight or two flights with a landing.
  • Normally open type stair with one side open.
  • Space constraints.
  • Only for small buildings/domestic buildings.
  • Any material.

Dog Legged Stair

  • Newel post are provided at the beginning and end of each flight.
  • There is no space between two flights.
  • A half spaced landing is provided generally to affect the change in direction.

Quarter Turn Stair

  • A stair turning through one right angle is known as quarter turn stairs.
  • The change in direction can be affected by either introducing a landing or by providing winders.
  • Rises to a landing between two floors, turns through 90, then rises to the floor above.
  • This type of staircase was much used in the two floor semi-detached houses.

Open Newel Stair

  • In these type of stair there is a well or opening between the flights in plan.
  • This well may be rectangular or of any geometrical shape and it can be used for fixing lift.

Three Quarter Turn Stairs

  • The direction of the flight is changed 3 times.
  • Used when the length and breadth of the stair room is limited.
  • Also the vertical distance between two floors quite large.
  • A stair turning through three right angles is known as a three quarter stair.
  • In this case, an open well is formed. This types of stair is used when the length of the staircase is limited and when the vertical distance between the two floor is quite large.
  • This type of stairs are used, when the length and breadth of the stair room is limited and the vertical distance two floors is quite large.

Bifurcated Stairs

  • If a quarter turn stair is branched into two flights at a landing is known as a Bifurcated stair.
  • This type of stair is commonly used in the public buildings near the entrance hall.
  • The stair has a wider flight at bottom which bifurcates into two narrower flights at the landing.
  • One turn into left and the other to the right.
  • This staircase has either equal or unequal flights.

Geometrical Stairs

  • These stairs may have any geometrical shape and they require no newel post.
  • This type of stair is similar to open newel stair except the well formed between forward and backward flight is curved.
  • Change of direction in such stairs is achieved by winders and not by landings.

Circular Stairs

  • They are also called spine wall stairs.
  • They consist of a central vertical wall from which the flights and half space landings are cantilevered.
  • All the steps are winders.
  • This is provided where space is limited and traffic is casual.
  • Mostly located at rear of building.

Based on Type of Material

  1. Wooden Stair
  2. Stone Stair
  3. Steel Stair
  4. Reinforced Concrete Stair
  5. Brick Stair

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