I have a new ceiling going up, into which are going some lights and an extractor fan. The electrics are in place awaiting for the return of the 'sparkie'. The holes for the downlight present no problems. The ceiling extractor will be fitted to 150mm ducting. My question is; what diameter hole do I need to leave for the fan to be fitted. Also do these fans come with an easy clip fitting to hold them in place on the ceiling or do I need to position some battens in place to screw the unit onto the ceiling. If that is the case, how far apart should those battens be?
Many thanks 👷😊