Hi there My husband is almost finished our extension and has put plasterboard with joint tape up all over. Can this grey stuff just be painted with Matt emulsion or do we need to treat/prime it with something first? If so, going to B&Q tomorrow so can get whatever I need then. Please explain what I need in simple terms LOL - none of your fancy jargon please hahahaha. Thanks in advance. Karen PS - This is a great forum, just had a nosey at some of the other sections too. May have to become a DIY enthusiast!!! Hubby will be so proud of me if all these great tips just come rolling off my tongue!