Have had problems with damp and mould in 2 storey extension with flat roof after a leak. Have now had new fibreglass roof fitted and same builder is going to replaster bedroom and bathroom affected. In bedroom he is going to put batons and plasterboard then skim. Is it ok to do this if walls are still damp with black mould. When I questioned builder he said it would be ok as it would allow airflow. Am I worrying too much
