All drain pipes shall be properly secured by irons to walls, supported from floor timbers by strong iron hangers, or run on brick piers, and shall not be laid underneath the cellar floor except where absolutely necessary, when permission shall be obtained from the City Engineer. All pipes shall be given as much grade as is practicable, but in no case less than one-fourth inch to one foot.
(1967 Code, § 16-9) Penalty, see § 10.99