(2)No person, other than a licensed plumber, shall execute any work described in chapter 24, chapter 25, and in this chapter, and no person shall permit any such work to be executed except by a licensed plumber:Provided that if, in the opinion of the Municipal Commissioner or the Executive Officer, the work is of a trivial nature, he may grant permission in writing for the execution of such work by a person other than a licensed plumber.
