Section 49(7) in Faridabad Complex Administration Building Rules, 1989
(7)The inside of every chimney flue shall be properly rendered or parapeted so that flue is carried upward unless the whole flue is built with fire brick or fire proof piping or fire clay or at least 2 centimetres in thickness in which case the spandrel angles shall be filled in solid with brick work or other incombustible materials.
