Jack came to study science at UCC in 1977 and became immersed in theatre with The Dramatic Society at the Old Granary theatre. Since then he has worked mostly in the theatre business.
He was a founder member of Meridian Theatre Company and worked with the company for a number of years, mainly as an actor.
He has also acted with Graffiti Theatre Ccompany and Corcadorca Theatre Ccompany. He has written scripts for The Everyman Palace, Macra na Feirme and RTÉ radio. He has also taught extensively.