Hi i have recently stripped a terraced house in prep for plaster, however i have found that some parts of the walls painted under the paper and its coming off all bitty. i was thinking of scraping as much of the loose off then applying a bonding agent like that stuff from wickes the night before,what do you pros think? also should i make sure that all wallpaper paste residue is washed off before i bond or pva it ? thanks :-\