What is the typical function of weep hole spacing in a brick veneer cavity wall?

• A. Allow moisture to drain from the cavity and equalize pressure at the bottom of the wall.
• B. Allow air to circulate to interior spaces.
• C. Provide a place to mount decorative hardware.
• D. Increase the wall's thermal mass.

Answer: (A)

The key idea is that weep holes are there to keep the brick veneer cavity from trapping moisture. Water can get into the cavity from rain, dampness, or capillary action, and if it can’t escape, it can create hydrostatic pressure that pushes moisture into joints or causes staining and deterioration. Weep holes give a controlled path for that water to drain out to the exterior and they also let air move through the cavity to help it dry. Spacing is designed so there are enough outlets along the wall so moisture doesn’t accumulate anywhere, and the cavity can vent and drain effectively. The other options don’t fit because weep holes aren’t for transferring air to interior spaces, aren’t mounting points, and don’t increase the wall’s thermal mass.