The following work is exempt from this chapter:
(1) a public work that involves electrical or mechanical engineering, if the contemplated expense for the completed project is $8,000 or less;
(2) a public work that does not involve electrical or mechanical engineering, if the contemplated expense for the completed project is $20,000 or less; or
(3) road maintenance or improvement undertaken by the commissioners court of a county.
Official text of the Texas Occupations Code as published by the Texas Legislative Council.