I have a problem with dampness in the external wall. I have been told it is due to water from the roof not going through the usual channel ie. gutters!! Subsequently a damp proof sheet has been placed in order to direct rain water into the gutters. However the problem is still persisting and i do not know what to do next. any advice is appreciated. In addition there are drops of water falling from either the gutter or the edges of the roof at some points.