Hi, I've been reading some posts and noticed that apparently putting damp proof 'stuff' over render is bad? My house had render over the damp proof course and i asked a builder to remove it. He removed it and replaced it with more render mixed with damp proof stuff, when queried he said this was a recognised way of dealing with the problem - should I be calling him back and asking if he can remove the render that he so painstakingly applied?