Weep

A weep or a weep-brick is a small opening that allows water to drain from within an assembly. Weeps are located at the bottom of the object to allow for drainage; the weep hole must be sized adequately to overcome surface tension.

In building construction, weeps are typically found in a masonry cavity wall, just above the flashing. Weeps may take several forms, including:

Open head joints (the vertical joints between bricks)
Cotton rope wicking
Formed plastic or metal tubes, which may include insect screening.

Weeps may also be necessary in a retaining wall, so water can escape from the retained earth, thus lessening the hydrostatic load on the wall and preventing moisture damage from freeze/thaw cycles. In such cases the weeps consist of small-diameter plastic, clay or metal pipes extending through the wall to a layer of porous backfill.

Typically, weeps are arranged to direct water which may have entered an assembly from outside back to the outside. Weeps may also be found in metal windows and glazed curtain walls to permit internal condensation to escape.

Weeping with regard to the human behavior of crying is often thought to come from a combination of the words "wimper" and "peep"