Ceilings, plasterboards, and top of walls cracks

[akist]

Hi guys, I have these basic questions as I am about to have some plastering done.

Is it recommended or obligatory to scrim tape the joint at the top of the wall where it meets the ceiling? Will this help or prevent cracks? Or is coving the only way?

We have plasterboards fixed into the ceilings. Is it required to use scrim tape over all of the plasterboards joints? Some have larger gaps than others. And in some rooms we have used insulated plasterboards which move more than the non-insulated ones.

 

[oldbutnotdead]

Yes tape all the joints- paper or (much easier) mesh.
Your pb walls shouldn't really be moving that much and there should be no difference between just pb and insulated pb.
What is the support structure, how is it tied to the ceiling or solid walls?

 

[akist]

OK, so I need to tape all joints between plasterboards, insulated or not.

If some gaps are larger, or there is some small areas of damage, say bashed plasterboard corners, is it better to fill the larger gaps with something or let the gap be and simply tape over it?

************************

Insulated plasterboard gives way much more, depending on the strength and condition of the backing material (insulation and thick paper), so when you look at the ceiling you see how some screws have pushed the boards in deeper, in places. It is more "spongy" than standard board.