Only the rioters now remain at the top jail at Waikeria, with the rest evacuated, the head of the Corrections Department says.
Four prisoners involved in the disorder surrended overnight, but 17 are still refusing to cooperate.
Rioting started early yesterday afternoon at the Waikato facility.
Corrections chief executive Jeremy Lightfoot said it was unlikely the old part of the jail - built in 1911 - could be salvaged.
"There's been an extensive fire damage to the top jail facility and there is continuing activity from Fire and Emergency New Zealand to ensure that any residual fires are under control."
Some 212 men had been moved, he said.
Lightfoot said it was disappointing the group remaining disregarded the wellbeing of staff and fellow prisoners.
He said a resolution may take some time.