what are weep vents

Weep vents, also known as weep holes, are small openings that allow water to drain from within an assembly. They are typically located at the bottom of an object to allow for drainage and must be sized adequately to overcome surface tension. Weep holes are commonly found in masonry veneer or cavity walls, just above the flashing, to drain water back out through the weep holes. They allow wind to create an air stream through the cavity, which removes evaporated water from the cavity to the outside. Weep holes are also placed above windows to prevent dry rot of a wooden window frame. In automotive water pumps, weep holes protect the bearings by letting out water that leaks past the seal. Weep vents are small devices inserted into masonry cavity walls during construction to form functional holes in a weep wall that help with drainage and ventilation of a structure. Without weep holes, a buildings structural integrity and the health of its inhabitants may be at risk due to the various problems these vents can prevent.