In the construction, installation, maintenance, use, repair, extension or alteration, removal or dismantling of any plumbing system or device or any part thereof, the specifications to be met, the materials and devices to be used, the methods to be employed and the standards of workmanship shall conform to nationally accepted standards as stated in publications of recognized experts in the fields of plumbing and sanitary engineering; and compliance with the provisions of the current edition of the National Building Code recommended by the American Insurance Association shall be prima facie evidence of compliance with this section. (1972 Code §16-1.)