Treads and risers of each flight ofa s ta ircas e or ofsevera I flights in the same staircase in a public or a wareho use and indus trial or a residential building shall be of unifonn width and height except where prior disrensation is specifically o btained from the Chief Administrato r for a rc h itcctura effect.
'[79. Location of Staircase. - The staircase in a ny building shall be so loented th at the travel distance on the floor shall not exceed 30 m.]
' [80. Dclcted .]
'[81. Head room ill a Staircase. - T he minimum clear head ro om in a passage under the lending of a s taircase and under the staircas.. sha ll be 2.1 rn.]
r (82 . Provision of"alld rails. - (a) In every staircase a tleas t one hand rail sha ll be pro vided w ith a minimum height of90 ems. from the centro of the tread .
(b ) W here slops a re provided from ground to the bui Id ing hond rail may not be provided, if the ste p do not go above 1.J7 m. in height and not less than 18m. in width.] .
1 [83 . Deleted.]
'[84. Residential buildings and commercial buiidings. - The minimum width of any lobby, corridor, passage or a balco ny in a residential building or a eom mercinl building sha ll be as given below:- . (a) N umber o f users upto 10 ' 0.9 M
(b) Number of users from II to 20 1.1 M . (e) Number of users from 2 1 to 100 1.25 M
(d) Increase 25 e ms. for every additional 15 persons until a maximum of2 .5 .M is reached. Wall and roofs shall be of the resis ting materials .] .
' [85. Public bllildillgs mill warehouse bultdlngs, - The minimu m w id th of any lo bby, corridor, pas sage or balcony in a public building or a warehouse and l.urustrta l Lullding to be used by the public shall be 1.4 M provided that in case of Lujld ing where more than 20 perso ns are likely to work o r assemble the minimum w id th shall be:- ~
(a) Number o f users from 20 to 100 1.8 M .
(IJ) Number ofusers from 101 unwa rds 2 03 M . Occupancy shall .be calculated on each floor. Walls a nd roof shall be of f:re-rcsisting matcrials.]