National Electrical Code (NEC)Article 358 - Electrical Metallic Tubing (EMT)Section 358.30 - Securing and Supporting(A) General. EMT shall be securely fastened in place by approved methods at intervals not to exceed 10 feet and within 3 feet of every outlet box, junction box, cabinet, or fitting.

Exceptions:(1) Where EMT is concealed within walls, ceilings, or floors that are securely fastened in place.(2) Straight lengths of EMT not exceeding 20 feet in length shall not require additional support if they are securely fastened at one end. Flag for review