The Corrective Services Commissioner says dozens of young offenders will need to be housed in an adult prison for six months after a riot at a juvenile detention centre earlier this week.

71 detainees were taken to Hakea Prison after a riot at the Banskia Hills juvenile detention centre on Sunday night.

Ninety cells were damaged as 60 male inmates climbed on to the roof armed with makeshift weapons.

Commissioner Ian Johnson says it will take six months to repair the damage, and juveniles will be phased back into the Banksia centre as appropriate.

He says he is confident the juveniles housed at Hakea will be kept separate from the adult population.