Newly plastered walls need further skimming; how to prep?

[problemdiyhelp]

My plaster has plastered a few walls (brick to plaster no boards) which once dry have been found to be quite a bit uneven in the surface finish (a few too many humps and bumps for me to be happy). He’s told me that he’ll come back and add a further skim to even things out and get the even/flat finish. What preparation should I do before he comes? i.e. should I score the existing skim with a Stanley knife and give it a coat of diluted PVA or is it ok for him to add a further skim straight on top of the existing skim (please note that the existing skim feels a bit on the polished side)?

 

[roughcaster]

The majority of guys on here would say that if a plasterer can't do the job right the first time, there's little chance of him getting it right at all. As regards to you preparing for him,,, don't!. Pity you got a chancer in the first place. A competent plasterer would have known how to do it right in the first place.

 

[problemdiyhelp]

Hi roughcaster, Thanks for your input. You are probably right about his competence but as most of the walls he did on a previous occasion are ok and the fact that he’s offered to resolve the problem without further cost means on this occasion I’ll put it down to him having an off day. As such should I expect to see him prep the effected walls with Stanley knife scores and a coat of diluted PVA or is it ok for him to add the further skim straight on top of the existing skim (please note that the existing skim feels a bit on the polished side)?

 

[roughcaster]

As you said, it may have been an off day for him, so we'll let it go.
If it's just a case of skimming over the wall again, i'd give it a coat of pva to seal it/kill suction, let it dry, then pva again, and skim right away while still tacky. I'd let him do the prep though. If the wall he did feels shiny/overpolished, there would be no harm in you going over it with a "rough sandpaper", but scoring it with a Stanley knife just for a skim is a bit exteme. Give it a good sand, tell him you did it, and leave the rest to him.