Exterior swing doors are critical leakage points in the building envelope. This article details how to properly flash and seal door jambs and heads to ensure continuous air and water protection in residential and commercial wall systems.
Importance of Flashing Swing Doors
Swing doors experience high levels of use, wind exposure, and potential bulk water drainage from above. Improper flashing can lead to wood rot, air leakage, and damage to finish floors. Doors must be integrated into WRB, air barrier, and drainage planes using a sequenced flashing approach.
Flashing Strategy
- Install head flashing above the frame, sloped outward with a drip edge and hemmed lip
- Wrap jambs with flexible flashing tape from threshold to above the head
- Overlap WRB over the head flashing and jamb flashing with downward laps
- Use compatible sealant behind flanges and under corner trims
Sealant and Backer Rod Integration
Apply backer rod and high-performance sealant at the exterior joint between the door frame and cladding. Use a toolable joint with proper depth-to-width ratio. On the interior, install air seal using either foam, sealant, or gaskets at the jamb and head perimeter
Quality Control Tips
- Check overlap of flashing layers at corners and terminations
- Inspect fastener sealant coverage and avoid overdriving screws through WRB
- Test for air leakage using smoke pens or blower door diagnostics
- Photograph each door condition for warranty and code documentation
Conduct water spray testing in accordance with ASTM E1105 where required for high-exposure assemblies.
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