Section 202(a) in The Building And Other Construction Workers '(Regulation Of Employment And Conditions Of Service) Central Rules, 1998
(a)no trestle scaffold is constructed with more than three tiers or if its working platform is more than four point five metres above the ground or floor or other surface upon which such scaffold is erected, such trestle scaffold is designed by professional engineer and has the approval of Director General before being taken into use;
