Hi there, I am new to this forum but would be very grateful for some advice from fellow plasters. I have been in the building trade for about 20 years and in the last 10 years set up by myself and taken on a lot more plastering work. however, a few months ago a took down an old ceiling in a massive kitchen, moved a wall, re-boarded it with 9.5mm boards, skim taped it, screwed it up exactly the same as I always do and skimmed it. Then 3 months later it has started to crack and has come loose in places. The house owner is obviously not happy and has left threatening voicemail messages on my phone. He thinks the timber we screwed into wasn't thick enough and so he and the other builder I was working with have put in a lot more timber above and re-screwed, filled and repainted but it is still cracking. I really don't know why this is happening. I haven't done anything different to any other ceiling I have boarded and skimmed? I am going back today to try and work out why this is happening. It is a 80's built bungalow so there is nothing above the kitchen. My initial thought was that the thin factory made trusses they used in the roof maybe causing slight movement to the ceiling? The owner of the house is adamant that this is not caused by movement from above and is because we haven't screwed the boards up properly but I didn't do anything different to any other ceiling I have done. I really don't know why this is happening, can anyone help?