What is the size of a weep hole?

• A. 1/4 Inch
• B. 1/2 Inch
• C. 3/4 Inch
• D. 3/8 Inch

Answer: (D)

Weep holes are openings at the base of a brick veneer cavity that drain moisture and vent air so the wall doesn’t collect water. The size needs to be large enough to allow water to escape and air to circulate, but small enough to minimize pest ingress and keep the cavity from weakening. Three-eighths inch is a common standard because it provides enough flow to prevent standing water and clogging, while still restricting insects and debris from entering. A smaller diameter like a quarter inch can clog more easily and reduce drainage, while a larger size such as a half inch or more can invite pests and affect the wall’s weather performance. So, three-eighths inch hits a practical balance and is the typical, best-supported choice.