Ceiling insulation

[Tofa83]

Hi

I'm currently redecoration my front room, the walls are not cavity walls so heat retention is almost non existent

I've pulled all the lathe and plaster off the walls and ceiling, with the intention of creating an insulated internal wall and was going to put insulation fiberglass in the ceiling before I put plasterboard up

If I'm insulating the ceiling (bedroom above), do I need to think about a vapour barrier?
Would solid insulation boards be better?
Do I need to have gaps around the lights (going to install downright)

Thanks
Chris

 

[EFLImpudence]

Do I need to have gaps around the lights

You do need gaps which defeats the insulation which isn't really necessary with bedroom above.

(going to install downright)

Those Chinese downlights are rubbish.

 

[Tofa83]

As I already have the ceiling off, and fiberglass rolls arn't too expensive I was going to chuck some up there before I put the boards on

Definitely needed over the bay window