When an exterior wall cladding is made of masonry, such as brick, a 25 mm (1 “) air gap is provided behind it to prevent rainwater on the surface of the brick from coming into contact with the structure of the walls.

To allow drainage of water from the back of the siding and promote drying of this cavity, weep holes (openings) are intentionally created by leaving vertical joints without mortar every 800 mm (32 in) in the first row over the foundation wall, built-in balconies, windows and doors.

These weep holes can also be made by inserting a plastic tube into the openings. The absence or the obstruction of weep holes promotes water infiltration inside the walls and may cause damages that are not always visible.

To prevent this, it is recommended that the weep holes in the masonry joints are never blocked. In their absence, avoid creating them yourself and check with a licensed masonry contractor for the feasibility of such an operation. The back of the brick wall is composed of membranes and flashing that can be easily damaged when a mortar joint is drilled. If you have any doubts about the integrity of the internal components of the wall, contact Legault-Dubois for a thorough investigation.