Plastering

#1
Hi,
We’ve had issues with heating and the plumbers are cutting a channel to fit a new return this will involve several holes and a few channels in existing plasterboard. They are patching the holes with the existing plasterboard that’s been cut out and then the ceilings will be re-skimmed over the existing boards which are already skimmed with plaster and the patches board. My question is should the plasterboard be removed in its entirety or will it be ok once skimmed over the patches? I have concerns the plaster will crack around the patches. The builder thinks this will be ok? Just wanted a second opinion from a plasterer. Any advice would be appreciated
 
#3
Hi,
We’ve had issues with heating and the plumbers are cutting a channel to fit a new return this will involve several holes and a few channels in existing plasterboard. They are patching the holes with the existing plasterboard that’s been cut out and then the ceilings will be re-skimmed over the existing boards which are already skimmed with plaster and the patches board. My question is should the plasterboard be removed in its entirety or will it be ok once skimmed over the patches? I have concerns the plaster will crack around the patches. The builder thinks this will be ok? Just wanted a second opinion from a plasterer. Any advice would be appreciated
I would cut the plaster away so I cut tape up the joint properly and then patch.