Hi. I have recently replaced my lean to with new poly carbonate. At the front of the house, the side door has a few courses of brickwork which have capping stones on top. The lean to runs up to this door. The problem is the lean to starts higher than this flat capped wall above the door, then the pitch of the roof takes it lower than the caps. This means I can't flash on to any one side of the cap stones because of the transition of angle. I'm sure there is a correct method for this situation, any help greatly appreciated.