No person, except a single-family homeowner
in his own dwelling, shall perform any water piping, plumbing or drainage
work, or shall expose the sign of plumbing or drainage, or any advertisement
in connection therewith, or engage in the business of installing,
repairing, replacing or altering any plumbing, drainage system or
fixtures, unless such work performed is under the direct supervision
of a state licensed master plumber.