What are weep holes?
Small openings spaced along the bottom course of a brick veneer that permit water trapped behind the wall to drain outward.
Weep holes are deliberate gaps left unfilled in the mortar joints of a brick veneer's lowest course, positioned to let water escape from the cavity behind the wall. When rain penetrates brick or when ground moisture wicks upward, water collects in the space between the veneer and the backup wall or structure. Without a drainage path, that trapped moisture causes deterioration of both the brick and the structural components behind it.
These openings typically measure between 0.25 and 0.5 inches and sit at intervals, usually 16 to 24 inches apart along the base of the wall. They work with a flashing system installed just above the foundation to direct water toward the weep holes and out of the building envelope. Some contractors use plastic or metal weep hole plugs or screens to keep pests and debris out while still permitting water to exit.
Proper placement and maintenance of weep holes is critical in Connecticut's climate, where freeze-thaw cycles and seasonal moisture can accelerate damage if water remains trapped behind veneer. Building codes require them in new construction, but older masonry may lack them or have them blocked by paint or mortar over time. Brick masonry contractors inspect and clear weep holes during maintenance to keep drainage paths open and extend the life of the veneer.