Hi and thanks for replying. No, not stone. The stairs are made from new timber and the underside was covered with wire mesh to allow the plaster to be built up.
I have just put in a new staircase and the underside was filled in with wire mesh and then plastered - approx 10 days ago. The plaster has now dried out except for four or five spots which still appear damp and dark in colour. A couple of the spots have sprouted a white furry bloom. There are no pip...
