Damaged Lath and Plaster Ceiling

[C.M-M]

We are currently refurbishing our bathroom and installing a new suspended plasterboard ceiling to replace a suspended tongue & groove ceiling. When removing the t&g ceiling this evening, I noticed that the old lath & plaster ceiling above has a large hole in the plaster, about 50 x 80cm, exposing the wooden laths. With funds being very tight at the minute, I’m wondering do I need to repair the lath & plaster ceiling before installing my false ceiling, or would it be okay to remove any loose plaster and install my ceiling beneath it? What’s the correct way to go about this?
Thanks in advance

 

[flameport]

Unless it's loose and falling apart, leave it as is.

 

[C.M-M]

Thanks for your response.
And if the plaster is loose and falling, is it safe enough to remove the loose pieces and then install my new ceiling as planned?

 

[Footsoldier888]

I have heard these ceilings can come down all at once if you pull down on loose bits as there is a fair bit of weight with not a lot fixing them. Isn't it better to overboard it in such a way that it all gets resecured to the joists?

 

[bobasd]

see if the ceiling joist are fixed and secure.just lightly push up an look for movement.
is the ceiling level two ways?
if alls good then just screw the new plasterboard up without messing about with the laths or loose plaster.

 

[C.M-M]

Thanks for you’re reassurance, I’ve installed the new ceiling directly beneath and left the existing one untouched!