What is the purpose of weep holes in masonry walls?

Weep holes play a crucial role in masonry walls primarily by preventing water accumulation behind the wall. When moisture enters the wall system, whether due to rainwater infiltration or moisture migration, it needs a way to escape. Weep holes act as drainage points that enable this trapped water to flow out rather than accumulating and causing damage such as mold growth, deterioration of the wall materials, or structural issues over time.

These holes are typically placed at regular intervals near the bottom of the wall, allowing for gravity to assist in draining water that may seep through the masonry. This effective drainage system is essential in maintaining the integrity and longevity of the wall structure.

The other options, such as providing air circulation, structural support, or enhancing aesthetic appeal, do not accurately reflect the primary function of weep holes. While some ventilation might occur in a well-designed wall system, it is not the primary purpose of weep holes, nor do they contribute to the structural integrity or aesthetics of the wall in the same significant way they do to moisture management.