Commercial Building Inspector B2Building EnclosureHard
A commercial building inspector is reviewing the flashing details for a window installation in a masonry veneer wall. According to IBC Section 1405.4, what critical component is required at the base of the window opening to direct water that penetrates the veneer to the exterior?
- AA flashing with end dams extending to the exterior face of the veneer.
- BA vapor permeable weather-resistive barrier.
- CA backer rod installed between the window frame and the rough opening.
- DA continuous bead of sealant around the window frame.
Show answer & explanationAnswer & explanation
Correct answer: A. A flashing with end dams extending to the exterior face of the veneer.
IBC Section 1405.4.1 requires flashing to be installed at the base of all wall openings in masonry veneer to divert water to the exterior. This flashing must have end dams to prevent water from running back into the wall cavity and must extend to the exterior face of the veneer.
Why the other options are wrong
- B. A WRB is behind the veneer, but the flashing at the opening base is a distinct and critical component for managing water at that specific location.
- C. A backer rod is used with sealant to create a proper joint, not to divert water out of the wall cavity.
- D. Sealant is for sealing joints, not for diverting bulk water that has already penetrated the veneer.
Masonry Veneer Window Flashing
A critical component at the base of window openings in masonry veneer walls designed to capture and redirect water that has penetrated the veneer to the exterior.
- Required by IBC Section 1405.4.1.
- Must have end dams to prevent lateral water movement.
- Extends to the exterior face of the veneer.
Memory trick: Flashing with end dams: a little dam for every window.