What is a weep hole? A weep hole is described as an opening that is placed in mortar joints of facing materials at the level of flashing (barrier), to permit the escape of moisture, or openings in retaining walls to permit water to escape. These holes also help provide proper air flow.
Why are weep holes necessary? Weep holes are necessary as bricks are porous. Water can absorb into the brick and then run down the backside of the bricks. If the water cannot drain appropriately, then this could cause the water to pool inside the wall and cause structural damage to your home.
Weep holes are created to prevent this damage from occurring. They are an escape route for the water that has accumulated, however, these holes do not reach your homes interior. These holes only go as deep as your home's exterior sheathing (the panels attached to to the outer wall studs). If you look closely at the outside of your home, you may also find weep holes above your doors and windows. This often depends on local building codes and the mason that performed the work.
Depending on the mason that helped to build the brick walls on your home or business, weep holes will vary. Some weep holes are created using circular, hollow tubes inserted into the mortar joint and left in place after adding mortar to the rest of the joint. Other weep holes are created by placing a temporary object, such as an oiled rope, in the mortar joint and then pulling it out once the mortar begins to harden, thus leaving a small hole. Weep holes are also sometimes created by putting a thin piece of sheet metal or plastic over a mortar joint, so no mortar enters the joint at all.
Weep holes, while providing drainage, also help to provide ventilation. These holes lead to an air cavity that lies between the exterior sheathing and the brick. This cavity is usually about an inch wide and allows for air flow, which helps to reduce the amount of moisture in the air cavity.
While weep holes may not reach your home's interior, you should still check them periodically, as insects and sometimes even mice or snakes can get into these spaces. To keep these unwanted creatures out, try placing steel wool or pieces of plastic rubber in the openings. These materials will block the opening, while still allowing for the necessary drainage and air flow. If the entire mortar joint is open, you can consider filling it with a custom product made for filling open mortar joints, such as steel weep hole covers.
If you have any more questions, contact our team of expert technicians and masons! We provide chimney repair, stone masonry construction, chimney inspections, concrete work and other masonry restoration services in Racine, Kenosha and Milwaukee counties.