can anyone help me, i have recently had a bedroom replastered but in one of the top corners the plaster hasnt dried out and has left some white residue. there is an airbrick on the outside wall opposite the damp patch which was sealed up when the cavity wall insulation wall installed. i think there could have been a vent on the inside which had been removed in the past and plastered over. if anyone knows how i can solve this problem or give any advice on who best to contact please let me know, thanks Simon.
