Is it necesarry to use joint compound ?

[Gary111]

Hi, if I want to patch a lath and plaster ceiling with plasterboard, do I need to buy joint compound?
Or can I fill in the edges with multi finish?
And possibly skim with that too?

Thanks

 

[Wayners]

Yes.

Gypsum based products like plasterboard or plaster is no good over walls that have or need lime plaster. Gypsum will trap moisture. Lime plaster won't.

For what you are doing to a lath ceiling you can use joint compound or plaster.

 

[Gary111]

Thanks mate, I am planning to leave part of the lath and plaster up but want to re inforce the plaster in those areas, is that possible?

 

[Wayners]

I've propped lath and plaster and vacuumed the back. PVA. Poured multi finish overs. Leave for 24h and removed props.

Was mentioned on skill builder (YouTube) to pour PVA over the back as that sets is hard although I've never tried.
If possible pull the lot down. Just replace the lot with plasterboard.

Yes. Go with your plan

 

[Gary111]

Thanks Wayners, if I pull all the lath down to fit plasterboard, would I need to add a frame under the joists for support in possibly 2x 1?

Or can I just screw the plasterboard to the joists?

 

[Wayners]

Screw plasterboard directly to joists.
I put cross timbers in-between joist at board edges so all sides of plasterboard has support.
CLS Timber - 38 x 63 x 2400mm

Hire board lifter

 

[Gary111]

Thanks for your help mate, if there is a stud wall under the ceiling that doesn't end on a joist, will I have to plasterboard to the next joist in the adjacent room?

 

[Wayners]

Can you add timber to fix plasterboard to?

In some houses the last few rows of blocks were not laid until ceilings were boarded. Then blocks laid up to plasterboard. I used to add timber to fix plasterboard to at wall edge when replacing ceiling

 

[Gary111]

Thanks Wayners, I would then have some lath and plaster only supported on one joist, is that ok?