The album - which follows the band's successful debut album, Newfoundland, released in 2010 - has won rave reviews for its sweet melodies and harmonies and has gained the band a solid fan base.
Rianz managing director Chris Caddick said folk music had become increasingly popular in New Zealand in the past few years. The band was a very deserving winner this year. He called their album "world-class".
"With Halves, Great North has fully realised the potential hinted at in its earlier releases.
"From the sophisticated lyrics to the marvellous instrumental accompaniment - this is a world-class album of which the band should be rightly proud."
Finalists for the 2013 Folk Tui Award included Brenda Liddiard, of Auckland, for her album Box of Memories and Wellington-based duo French For Rabbits, for Claimed By the Sea.
Past winners of the Tui Best Folk Album award include Amiria Grenel for the album Three Feathers, Auckland bluegrass quartet Wires & Wood for Over The Moon and Phil Garland for Southern Odyssey.