lumps of plaster coming off ceiling

[labrador2]

We have just had a new kitchen extension. We gave the newly plastered ceiling one thinned coat of emulsion, but noticed that when dry, the paint appeared to be 'parting company' with the ceiling over what appears to be the nails in the plasterboard.
Minutes ago, this fell off the ceiling, attached to lumps of the plaster underneath.

Will we be able to 'fill' these or need to apply more plaster?

It has only happened on one small section of the ceiling.

 

[spice]

Do you mean that the plaster around these nailheads have popped ? (plaster come away from the nailheads)

 

[labrador2]

yes, and about an inch of the surrounding plaster.

 

[spice]

Thats what I thought,and if you fill or plaster over them again, sometimes they still pop, it is quite common.
Heres what I do when I come up against this in my jobs, and this does solve the problem for me.

Remove any of the blown/fallen plaster away from the nail heads, dab the area where its come off with some slightly diluted PVA.
When dry, fill over these 'Nailheads', with filler, dont use the readymade stuff.
Rub down when dry, then apply again a liberal amount of PVA to the actual filler, leave to dry, you might have to fill again,as the first lot of filler probably wont fill it, so if need be, fill again until it feels flush against the ceiling.
Again, sand down and apply your PVA over the filler, then before you start on your coats, just brush these filled areas a couple of times with your emulsion before you start to roll.

The PVA will form like a hard shell film over the filler and stop the filler from cracking around these nailheads.

 

[54aardvark]

The plasterboard is loose around the nailheads and once this has happened it will keep occurring at the slightest expansion/contraction

You need to stabilise the plasterboard - simplest solution is to put in plasterboard screws, put one in about an inch away from every blown nailhead, screw in till its flush with the surface but make sure the heads don't perforate the paper skin on the plasterboard (this is what caused your problem in the first place) and then fill & sand.

 

[labrador2]

Thank you, I'll let you know the results!!.