Hi guys. Couple of wks ago stripped ceiling of wallpaper with intention to artex. Ceiling in good nick so decided to paint. Used Dulux rich matt to avoid having to do several coats. First coat no problems but second coat blistered and peeled both coats but not all over. Advsied by friend of a decorator to sand down where peeled and use pva solution as paint had reacted to paste. Tried this but blistered even worse. Husband spent all day stripping off all paint, do we wash down with sugar soap first then emulsion or wash with sugar soap, seal with pva then emulsion. Please help!