Firstly, if there are signs of severe water damage, whether it be to a Gyprock or plasterglass ceiling. Water damaged ceilings can not be salvaged and must be replaced, or at least partly replaced. Furthermore, we would ensure that any source of water ingress was identified and addressed prior to any ceiling works.
Secondly, if the ceiling was warped beyond repair, we would recommend that the ceiling should be replaced. We can provide service for removal/disposal of old ceilings and replace with new. However, we believe that removal of existing ceilings to be absolute last resort (within reason) and would advise customer of alternative solutions.