I have a slight damp issue on a couple of exterior walls to my Victorian house. The outside paving and a driveway (likely big standard asphalt/tarmac) directly meet and touch my red brick walls. I believe that some some water is getting into the crack between the wall and floors. I would like to fill this as best as possible all along the outside of my house to provide water runoff. Approx 15m strip to cover. I am considering a bitumen mastic. Should this be ok or should I perhaps use another method? Many thanks in advance!