DIY Doctor UK DIY Forums

Hi, I recently purchased a new house that had a few issues with damp caused by having cavity wall installed (property is old and the wall insulation was soaked when removed). I have since removed the cavity wall insulation and plastered the house. In the dining room, damp patches that look like bricks have appeared halfway up the wall and a small section of the plaster has bubbled leaving a white chalky patch round it (I have since sanded this away)not letting me attache pic for some reason
Any clue what this could be??
Thanks in advance
Jamie