I have to replace some fluorescent fittings in a hall. The ceiling looks like it was built around the fittings so when the old ones come down, there will be an approx 4
If it's double layered with staggered and filled joints.
Depends on the requirements for the job from the customer, if in doubt, get someone in to advise. If it's meant to be fire rated then really you should patch it up so it is fire rated, if not then anything will do.