STAIRS
By MANISH S & RAGHU.T Faculty, DSCE
CONTENTS
Definition Typical terms used in stairs Requirements of good stair Formulae for finding going & rise of step Classification of stairs
Based on material Based on purpose
DEFINITION
It is defined as series of steps which are suitably arranged in a manner as to connect the diff., floors of building It shall be designed & constructed in such a way that it provides easy & quick access to the various floors Other than this, they shall provide maximum comfort & safety to user
Cont..
It is a very important component of a bldg., since it serves as only means of access outside the bldg., during a fire/ calamity. Hence of location of stair into a bldg is very important Usually for res. Bldgs, it is provided centrally so as to provide easy access to all rooms In case of public bldgs, it shall be located near main entrance If its a commercial/ office bldg, then they shall be provided at more than one place Cont..
TERMS USED IN STAIRS
REQUIREMENTS OF A GOOD STAIR
Location shall be located wherein sufficient light & ventilation is available Width of stair for public bldgs where number of people visiting bldg are more, it shall be 1.8m average & for residential bldgs 90cm Length of flight for comfortness, not more than 12 steps, minimum being 3
Head room it shall be not less than 2.00m( dist b/w tread & soffit)( as per NBC-2.15M for indian conditions) Material shall be constructed of material which have fire resisting qualities Balustrade these shall be given for open well stairs to minimize accidents if any
Landing width of landing should not be less than width of stair .
To sum it up
CLASSIFICATION OF STAIRS
Based on material
Based on function
STRAIGHT STAIRCASE
In this type of stair, all the steps are in a single direction If ascending is steep(i.e while climbing), the straight flight can be broken with an intermediate landing Usually found as a means of access for entrance ( very common in public buildings) also commonly found in bungalows/villas
DOG LEGGED STAIRCASE
Consists of 2 straight flights or steps which turn abruptly Usually, landing which is level is placed in between the 2 flights i.e.,@ change of direction Useful where width of staircase is just sufficient to accommodate 2 widths of stair Derives its name from simple fact that the dog leg & sectional elevation of stair resembles closely
Dog legged staircase ?
OPEN WELL STAIR CASE
Consists of 2 or more straight flights arranged in such a manner that clear space well is present between the backward & forward flights well can be either rectangular or curved in shape Series of steps b/w forward & backward flight
well
well
GEOMETRICAL STAIRCASE
Similar to open newel stair, but the difference being the well portion between forward & backward flight is curved Change in direction is obtained or given with winders
**winder- steps whose shape changes abruptly from straight to curve
CIRCULAR OR SPIRAL STAIR
Provided usually at the back side of building for getting access to various floors to carry out service works Usually built of cast iron, sometimes with rcc also All steps radiate from newel post, in the form of winders Not preferable which demands frequent usuage of stair Causes some discomfort to the users sometimes due to its curvature
BIFURCATED STAIRCASE
This type is used in government/public buildings which are newly built Here, flights are arranged in such a pattern that
wide flight is available at the start
This wide flight is again sub-divided into narrow flights at mid-landing The 2 narrow flights start from either side of mid landing
Was this required
Is it necessary
No-head room
Maximum utilization of labour
