There is a long time crack in the mortar between brickwork on porch wall. Porch is 6ft by 4ft single brick extension Crack starts under window and is then diagonal round the corner as far down as damp proof course. There is no damage to the bricks, but this whole section of wall seems to have moved by about 3 mm. Crack has been present for at least 10 years, but had not noticed movement until now.
