Hi everyone, I went and looked at the ceiling in question today and it looks like the whole lot is blown apart from a small area that was boarded.
One thing I remember is that the walls had blue grit on them for about 48 hours before they were skimmed and the ceiling had blue grit on just 15 hours before hand. Should I have left it longer before skimming?? who knows.... but it does say to leave for at least 6 hours for blue grit I believe. The blue grit is still on the ceiling and very sound, the finish has come clean off the grit without a trace except for dry dust from the finish. I will pva, bond & skim the ceiling to remedy this.
It will be put right, in my 30+ years of plastering I have had maybe 5 walls or ceilings that have blown but I learnt from my mistakes on them each time, blue grit & bondit seem to be the solution for areas that arent really suitable for pva but my confidence in using them has been dented.
Forgot to mention there was a sparky pulling and hauling at cables for low voltage lights 2 days after it was skimmed, he had a problem with a trapped cable somewhere in the centre of the ceiling. Mmmmmmmmm