Windows, Doors, and Penetration Interface Coordination
Interface Coordination
Windows, doors, and other penetrations are where water most often enters EIFS. The inspector coordinates the rough opening, the WRB, the flashing, the window or door frame, and the EIFS termination. The key concept is that the opening must be flashed and drained, and the EIFS must terminate in a way that does not trap water.
Sequence and Details
Verify that the rough opening is sized correctly, that sill flashing slopes to drain, that jamb flashing laps over the sill flashing, and that head flashing sheds over the jamb flashing. Confirm the WRB is integrated into the opening and that the frame is sealed or flashed per the manufacturer. EIFS should terminate with a backwrap or edge trim at the opening, with sealant in the joint between the EIFS and the frame.
Traps
Questions often test sill panning, end dams, and whether sealant alone at the sill is acceptable. Another trap is a head flashing that laps behind rather than over the jamb flashing, or a sill that slopes inward. Also watch for sealant joints that are too narrow or that bridge the drainage path.
Worked Example
If a window sill has no end dams and the flashing is flat, water can migrate laterally into the wall. The correction is to install sloped sill flashing with end dams and integrate it with the WRB, not to add sealant at the corners.
Rule of Thumb
Every opening should pass the "water flows out and down" test: head over jamb, jamb over sill, sill to exterior. If any lap is reversed, the detail fails regardless of sealant.