hi two year ago i had a local builder do me a loft conversion in my semi detached house with two velux windows and a small radiator, it is all plasterboarded and skimmed and insulated with kingspan, there are two doors either side with crawling space for storage. Recently i noticed a few damp patches appearing on the plasterboard at the bottom and upon investigation there is condensation running down between the kingspan and felt, but it only seems to be at both ends at the gable end side and the side with the adjoing neighbour, the kingspan is fairly thick 50-75mm thick and there doesnt seem to be much of a gap. there seems to be condensation patches in the crawling space but im unsure if its run down, ive got vented soffets but im assuming its a airflow problem see attached photos, and ideas or solutions to the problem would be greatfully appreiciated. would vented roof tiles or ridge tiles solve the problem
