What is the minimum diameter for weepholes located above flashing?

The minimum diameter for weepholes located above flashing is established to ensure that moisture can effectively drain from behind the wall system, particularly above the flashing where water may accumulate. A diameter of 3/16 inch is sufficient to allow for adequate drainage while preventing blockages from debris or insect entry.

This specification is important in building design as it helps to mitigate potential water damage by allowing trapped moisture to escape, thereby enhancing the longevity and performance of the wall assembly. Weepholes must be large enough to maintain good drainage but not excessively large, which could compromise structural integrity or invite pest issues. The choice of 3/16 inch strikes a balance between effective drainage and practical design considerations.