Door flashing is the system of flashing components installed around an exterior door opening, including head flashing above, jamb flashing at the sides, and a sill or threshold pan beneath, working together to direct water away from the door and prevent it from penetrating the wall assembly at this frequently used, weather-exposed opening.
Because exterior doors experience both weather exposure and physical foot traffic, their flashing system needs to address water management while also accommodating a functional threshold that people regularly cross without creating a tripping hazard or water intrusion point.
Sill or threshold pan flashing beneath an exterior door deserves particular attention, since this specific detail addresses water that could otherwise pool at the door’s base or work beneath the threshold into the subfloor structure below.
What Does Door Flashing Include?
- Head flashing above the door opening
- Jamb flashing along both sides
- A sill or threshold pan at the base
- Integration with the surrounding water-resistive barrier
Why Is Door Flashing Important?
Given exterior doors’ significant weather exposure combined with regular foot traffic wear at the threshold, proper flashing at this opening is particularly important, since water intrusion here can damage not just wall framing but also subflooring and interior finishes immediately adjacent to the door. This combination of exposure and consequence makes door flashing quality a meaningful factor in a home’s overall durability.
Sill pan flashing, a relatively modern best practice compared to older, simpler threshold details, has become increasingly standard in current construction specifically because water intrusion at door thresholds proved to be a common and costly problem in homes lacking this more comprehensive protective detail.
Door Flashing vs. Window Flashing
Door flashing addresses an opening with regular foot traffic and typically includes a sill or threshold pan. Window flashing addresses an opening without foot traffic considerations, though both systems share the fundamental principle of directing water away from the opening through coordinated head, jamb, and sill components.