Do not test the plaster yourself.
Poking, pressing or puncturing a damaged ceiling can put you beneath unsafe material. Do not enter an affected roof space or try to release water from the ceiling yourself.
Mention water near lights or fittings.
Do not touch wet electrical fittings or operate equipment around them. Electrical safety needs an appropriately qualified assessment. If there is immediate danger, call emergency services.
A short history helps.
Tell the team when the mark or sagging appeared, whether it has changed and whether there has been a known roof or plumbing leak. Mention any prior repairs and which rooms are affected.
Ask about the source as well as the ceiling.
A patch or paint finish cannot address an ongoing leak. The assessment should consider the cause, the affected materials and the sequence for safe cleanup, drying and repair.
For flood and electrical safety information
Follow emergency-service directions. For immediate danger, call 000. See NSW SES flood guidance and NSW Health household safety advice.