We purchased a new top floor flat a few months ago and during the recent cold weather have experienced major condensation problems, with water running down walls and windows, and coming through ceilings and light fittings. This is due to insufficient ventilation of the flat roof above, which the builders have now addressed by fitting additional ventilation holes in the soffit overhang. However, we are left with damaged ceilings and walls which now need to be repaired. The builder is due to start remedial work on Wednesday and originally told us he would be drylining before redecorating. Our understanding was that this would involve replacing damaged areas of plasterboard, then re-skimming the whole ceiling/walls with plaster, but we are now told that they will simply be using a drylining compound, and only for the affected areas, not the whole ceilings and walls. Is this the usual way of repairing damaged ceilings and walls?