In a grouted masonry barrier wall, is it better to place flashings at all floor levels or just at the base of the wall and above window openings?
It is better to put flashing in only where the collar joint has been interrupted, such as at shelf angles, at openings for windows or vents, at the base of the wall or above roof levels. Whenever possible, the grouted collar joints should be continuous to form a barrier. The grouted collar joints should be vibrated during construction to ensure that this barrier does not have holes or voids. Because a properly grouted collar joint will not permit water to flow down a wall system, intermediate flashings will not increase the performance of the wall system. In fact, the presence of intermediate flashings in the wall may reduce the wall system's performance because the cold joint formed beneath the flashings can serve as a bridge for water to travel between the wythes.