What are the openings left in the head joints of brickwork for moisture drainage called?

The openings left in the head joints of brickwork for moisture drainage are called weeps. Weep holes are essential for allowing water that accumulates within the masonry to escape, preventing moisture buildup that could lead to structural damage or deterioration. They are strategically placed to promote drainage and ventilation within the wall system, which helps to protect both the brickwork and the interior of the building from water damage.

Weep holes not only facilitate the exterior drainage of water but also assist in maintaining the overall integrity and longevity of the masonry structure by ensuring that excess moisture does not remain trapped. This feature is especially important in climates where rains are common and helps mitigate issues such as mold growth, efflorescence, and freeze-thaw damage.

The other options include elements related to moisture management but do not specifically refer to the openings in brickwork. Vents and drains serve other purposes in the context of building design and hydrology, while flashing is a material used to redirect water away from critical areas of a building but does not refer to the drainage openings themselves.