Movement and stresses created by temperature and humidity fluctuation, can result in deformation and damage to internal linings and partitions.
It is recommended that Gyprock plasterboard surfaces be isolated from structural elements, by the use of control joints or other means where:
• A plasterboard/wallboard surface abuts any structural element or dissimilar wall or ceiling assembly.
• The framing or structural support changes within the wall or ceiling.
• At all construction/control joints within the building.
• For non-tiled internal walls with plasterboard outer layer, at 12m maximum centres.
• For tiled internal walls, at 4.8m maximum centres.
• For external ceilings, at 6m maximum centres.
• At junctions with other building elements.
• At changes of lining material.
• At each storey or rise of studs.
Control joints incorporated in a building to permit movement in the structure must be carried through all areas lined with plasterboard/wallboard. Allowance for movement must be made through the frame, lining and any tiles. Door frames extending from floor to ceiling constitute control joints. For doors less than ceiling height, a control joint extending from one corner of the frame may be used.
Vertical control joints in stud framed walls are to be constructed using two studs with a 15-20mm gap between.

Attribution: CSR Residential Installation Guide. The RED Book