I think it is called Gyrock or Sheetrock .It looks cheaply done. The ceiling that is flaking is in the the hall and kitchen but it doesn't dip like the lounge area. . Yet the bedrooms are perfect . As this was built 30 years ago it has wear and tear. I live in Australia but I love Houzz. Thank you for all the information. I believe the palms outside the lounge leaned on the guttering. The palms have been removed . Yet we haven't looked in the roof area. There isn't mould .

You could look at a composite timber decking timber fixed to a black painted background leaving gaps between timber has a nice finish as in this photo it was used for all soffits and large rear verandah on this home. Regards Paul Wales

Good morning! I love love love your ceiling! As others have asked - is it something that repeats through the house? I would 100% keep them - the key is to work with them not fight against them. I would also replace the light fitting - look at having recess lights installed. There are a number of things that you can do when you have such a prominent feature such as this in a room - you either choose to work with it and 'calm' it down into the space - such as painting the ceiling and the walls in the same colour - or you say - to hell with it and make it the hero of the room. I have seen some stunning ceilings where the walls have been painted in a 'white' and the ceiling painted in a strong colour such as navy which then ties into accents in the room. It would obviously depend on your personal style. Good luck!

I would prefer to see both ceilings matched with shiplap, to help tie the space, we all tend to look up. This would also mean that the wall between both rooms can be removed and therefore make the room appear bigger, as the height of the ceilings in each room will make them appear smaller if the wall isn't removed