Thanks for your replies.
Vaulted ceiling is the end goal, with collar ties and ridgebeam to take load and prevent spread, so ceiling joists can then be removed.
So (and please correct me if I've got this wrong), to get to current standards that BC will be happy with, I need to remove...
Hi there. I'm vaulting the ceiling on a small terrace extension, 3x 5m (kitchen downstairs, bathroom upstairs). I don't know when the roof was last done, but suspect around 50's/60s. The original extension likely pre-dates this as it had lath and plaster ceilings. It has terracota tiles on top...