Please can someone explain to me what the difference is between plasterboard and drywall, if any? I have walls painted with emulsion that have a relatively smooth appearance, would this be drywall or skimmed plasterboard - how can I tell?
Also, I would like to sand the walls before repainting them but want to keep dust to a minimum, would it be okay to use wet 'Wet & Dry' sanding paper, say on the end of a pole sander? If yes, what grit is sufficient for a smooth finish, 180 or 240 - would I notice the difference?