Wednesday - June 7, 2023

Stair | Properties & Technical Terms of Stairs

Properties of Stair
Technical Terms of Stair!

  • A stair may be defined as a series of steps suitably arranged to connect different floors of a building.
  • The room or enclosure of the building in which the stair is located is called a staircase.
  • The opening space occupied by the stair is called a stairway.
  • In a residential building, the stair should be centrally located to provide easy communication to all the rooms.
  • During public buildings, stairs should stand located near each entrance.
  • That is built up of timber, bricks, stones, steel either RCC.
Properties of Stair, Technical Terms of Stair,  Requirements for good Stairs, Trade & Rise proportion of Stairs, A stair series of steps,

Technical Terms of Stair

  • Steps:- Some portion of a stairway consisting of the tread also riser which permits ascent about descent from one floor over another.
  • Tread:- This horizontal upper part of a step on which the pad is placed in
    ascending either descending stairway.
  • Riser:-  Some vertical portion of a step giving support to tread.
  • Flight:– Each series of steps without either platform about the landing.
  • Landing:- A platform or resting place provided between two flights.
  • Nosing:- The outer projecting edge of a tread is termed nosing. Nosing is usually rounded to give a good architectural effect to the treads.
  • Winders:- Those are reducing steps that are provided during changing the direction of a stair.
  • Soffit:- It is the undersurface of a stair.
  • Handrails:- It is supported on balustrades and usually run parallel to the slope of stairs.
  • Baluster:- It is a wooden, metal or masonry vertical member supporting a handrail.
  • Newel:- It is a wooden or metallic post supporting the handrail and is usually provided at the hand, foot or at points where the balustrade changes its direction.
  • Pitch or slope:- It is the angle which the line of the nosing of the stair makes with the horizontal.

Requirements for good Stairs


  • It should be located such that sufficient light and ventilation will come in a stairway.
  • If possible it should be located centrally to be easily accessible.

Width of a Stair

  • The width of a stair varies with the situation and the purpose for which it is provided.
  • In a public building, where there is regular traffic of people, its width
    should be 
  • A residential building may be just the minimum.
  • The usually adopted average width for public and residential buildings is 1.8 m and  90 cm respectively.

Length of Flight 

  • For a comfortable ascent, the number of steps in a flight should be restricted to a maximum of 12 and a minimum of 3.

Pitch of Stair

  • The slope of the stair should never exceed 40° and should not be flatter than 25°.


  • Some stairs should preferably last constructed of materials that maintain fire-resisting qualities.


  • The width of each landing should not be less than the width of the stair.

Step proportions:-

  • The rise also treads of each step in a stair should move of uniform dimensions completely.
  • Number of risers = Total height of floor / Height of riser
  • Number of trade= Number of risers – 1
Properties of Stair, Technical Terms of Stair,  Requirements for good Stairs, Trade & Rise proportion of Stairs, A stair series of steps,
Trade & Rise proportion of Stairs
  • The size of a tread and riser varies with the situation of the stair and the purpose for which it has to be provided.

In a general, these following thumb rules remain considered

  1. Going in cm * Rise in cm == 400 into 410 approx
  2. Going in cm + (2 x Rise in cm) == 60 approx
  • Adopt the standard size of going and rise to 30 cm and 14 cm
  • For residential buildings- Trade = 250 mm to 300 mm or Rise = 150 to 180 mm
  • For public buildings- Trade = 270 mm to 300 mm or Rise = 130 to 160 mm

Last updated on Monday - May 22nd, 2023