Barnes, a retired businessman, owned and operated J. J. Barnes, Inc., a mechanical contracting company specializing in commercial, industrial, and residential projects. The company was founded by Barnes' father, the late J. J. Barnes, Sr., in 1925. Barnes graduated from North Carolina State University with a Bachelors degree in mechanical engineering in 1949. An active church member, Barnes has served as deacon, Sunday school teacher, and member of the church choir. They have six grandchildren.
Barnes enjoys hunting and riding horses.