Flat roofs (older) with "deferred" maintenance can be a problem. With a bonded brick wall and a partially cavity, water obviously runs down and the drainage shows up there. Brick, despite it permanence is not waterproof and that is why the good walls are brick cavity walls.
With a roof leak, the interior damage may show up much higher or could be anywhere the water finds a path.
Last edited by concretemasonry; 12-12-2012 at 08:08 PM.