Stairs | stairs terminologies

  Stairs

In this article we discussed all information related to stairs 

what is a stairs?

A stair is a set of step leading from one floor to another floor on it provides medium of ascent or decent between various floor The roof an enclosure when stairs are constructed as staircase

The space occupied by stairs in stair case is termed as stair way

1 .Step

It is the portion of stair which permits ascending and descending

It consists of 2 components

1 Trade

2 Riser

A stair consists of set of step

2. Trade

It is upper horizontal portion of step over which foot is placed while ascending and descending

3. Riser

Vertical portion of stair providing support to the tread is termed as Riser

4. flight 

It is unbroken series of step between landing

5. Landing

It is the level platform at the top and bottom of flight 

It facilitates change of direction

It provides the opportunity for rest the during use of stairs

6. Rise

It is the vertical distance between the tread faces

7. Going

It is the horizontal distance between the two riser faces

8. Nosing 

The projecting part of tread is teamed beyond the face of riser is teamed as

It is usually rounded of from architecture  point of view 

9. scotia

A moulding provided below the nosing to improve its strength and elevation istermed as soffit

10. Line of nosing

Imaginary line parallel to string and tangential to string

11. Slope / Pitch

It is an angle made by line of nosing with horizontal

12. String 

The sloping member which supports the steps of stair is termed as string

13. Newel post

 It is the vertical member provided at the start of flight to support the hindrance

14 . Balusters

Vertical member provided to support hand rail after newel post

15. Handrail

It is  rounded portion  parallel to string used to provide support while using the stairs

16.  Run

Total length of stairs in horizontal plane including landing

17. Head room

Minimum clear vertical distance between tread and celling 2.3 - 2.5 m

18.  Header

It is the horizontal structural member provided to support the stair

terms used in stairs

Requirement of good stair

1 Location

It should be located such that it is easily accessible by all the occupants of the building

It should be well ventilated and well lighted from exterior

Width of the stair for domestic building it is 0.9 m and for public building 1.5 to 1.8 m

Length of the flight from comfort point of view no of step must not more than 12 and less than 3

Pitch/slope

It is kept in range of 30 to 40

Headroom

It is kept in range of 2.1 to 2.3 m

Material used for construction should be such that it has

1 Sufficient strength

2 fire resistance 

step dimension

It should be such that it provides comfort to the user

Going 25cm-30 cm

Rise 10-15cm

1 2 (Rise)  + going = 60cm

2  Rise + going = 40-45

3 Rise x going = 400-450

Generally Rise = 14 cm and going 30 cm is adopted

A thumb rule is followed for selecting other combination of rise and going for every 2 cm subtracted from going and add 1 cm in rise

Rise Going 15x28, 16 X 26

Types of stairs

• Straight stair
• 
  

  

  • Straight stair

  
  
  
  

It has straight run between the two floor either in single flight on more than one flight It is provided where there is restriction of width

•  Turning stairs

These are the type of stairs in which therewould be at least one change in direction

These are of following types 

1 Quarter turn stair

2 Half turn stair 

1. Dog legged 

2.open well stair

3. 3 quarter turn stairs

4. Bifurcated stairs

1 Quarter turn stair

quarter turn stairs 

When the direction of flight is change at right angle either to be left on to be right quarter turn stairs are used Suitability width more but length limited

2 Half turn stair

1 Dogg legged

It consists of two flight of stair which areopposite direction no space is provided between the flight in plan

2 Open well stair

A half turn stair with a space betweenits flight is known as open well stair Suitability multi-storey building

3. 3 quarter turn stair

A stair turning through 3 right angle isknown as 3 quarter turn stair

4. Bifurcated stair

Bifurcated stair

This type of stair has a wide flight of bottom which bifurcated in the narrow flight are turning in left side and other in right side at the landing 

Continious stairs

The stairs which do not have any landing or intermediate newel post are termed as continious stairs

These are  classified as

1. spiral 

spiral stairs

2. Circular

3. Helical

 Classification of stair according to material used 

1 Timber stair

Timber stair

• These stairs are light in weight and easy to construct 
• Very less fire resistant
• Suitable for small residential building 
• Unsuitable for public or large buildings 
• Timber used must be free from the effect of termites insect and fungi

2 Stone stairs

stone stairs

• It is widely used at places where ashlar stone is radially available
• It possesses strength rigidity resistance to wear and teak and fire will be more
• These stairs are comparatively heavy

3 Brick stair

• Uncommon
• Used in villages
•  Its wear and tear is comparatively more Hence maintanance cost is also more
• Generally used at the entrance or for the architectural purpose

4 Metal stairs

• These are made up of mild steel or cast iron
• These are use for emergency purpose 
• These are strong fire resistance but are not prefer in residential and public building as they are not looking and make noise

5 RCC

• These are most widely used stair both in residential and public building 
• These are strong hard resistant against fire Can be given any type of finish
• It can be cast in situ on can be precast