Can you tape and plaster joints only on plasterboard? IE not skim whole room?
sure, if you want to, give thema finish coat for best results
you can skim it, or blow it on to all of the wall, do any thing you want to it,
I only let a few of my drywall subs to skim whole walls. You have to know how & what you are doing. It can turn into a nightmare and get caught sanding forever & using 20 boxes of ready mix where 5 boxes are needed. Maybe you can sand your existing wall and lightly skim if you do not have too many coats of paint.
Yes, you can. You will find that the plaster board will soak up more paint that regular drywall. This is because there is a special paper on the plaster board that allows the plaster to stick to it. Plaster board is sometimes called blue board, and you'll know why when you look at the two side by side. When you get ready to paint, you might want to consider two coats of primer.
By plasterboard I assume you mean drywall. Yes you can tape and finish only the joints and screw holes. It is rare in my area for anyone to skimcoat the whole wall.
