Hi there, was after some advice. I have 2 patches of blown plaster internally, and outside in the corresponding places. I have removed some of the external render to find I have 2 damp proof courses, 1 is 2 inches above the external ground height and the other 2 courses above that, the mortar is very soft (can rub it out with a finger) is it lime or very weak cement, it is damp. Can I rake some out and repoint with cement or does it need to be lime as I intend to Re-render the exterior after, and does the render need to be something special or can I use hard wall/cement? The house is an ex local authority semi built in the 1930's, with red brick and then rendered, as is the whole street.