Weep Holes are openings placed in mortar joints of facing/siding materials of buildings, such as brick or veneer walls, at the level of flashings.
They have 2 purposes:
– Drainage: Water that enters the cavity due to capillary action, condensation, damage, faulty guttering or accidental flooding needs to escape somewhere.
– Ventilation of the internal wall cavity: Without ventilation, mildew, dry rot, and dampness reduce the life of the internal wall studs and other building materials within the cavity. Building materials can decay and break down over time and the house can become a health risk due to mildew, mold, humidity and dampness.
Many homeowners resort to blocking weepholes with any number of materials such as silicon sealants, rolled up paper, plastic, or steel wool to avoid rodents and pests from entering the brick. There are options to buy weep hole screens to fill these holes and still allow the weep holes to do their job. Unfortunately, some manufactured weep hole covers, guards and barriers have also been designed with holes too small to allow adequate ventilation. Buying the right screen is very important.
Weep Holes are not just for your house: Weep holes, or the equivalent of, are also present, or should be present, in retaining walls to permit water to escape. Water build up behind retaining walls, in cold climates allows for frost action (pushing, bowing, leaning) to take place as well as premature degradation of the retaining wall materials.