Flashing goes wherever water would otherwise get into the building: windowsills and heads, wall bases, shelf angles, roof-to-wall intersections, copings and penetrations. Materials include stainless steel, copper, aluminum, lead-coated copper, flexible membranes and composites. Flashing works by gravity and lapping, collecting water and turning it out past the face of the wall.
No flashing at the window head, water's running down the jamb and straight into the drywall.
Most flashing problems trace back to the ends and corners, not the straight runs, so inspect terminations first.
Also heard as
- flash
- flashings
Related terms
Through-wall flashing
Flashing that runs from the back of a masonry cavity out through the wall face to drain water outside.
Counterflashing
Flashing set into the wall above a base flashing, overlapping it downward to shed water off its top edge.
End dam
An upturned end at the termination of a flashing that stops water from running off the end into the wall.
Shingle lap
Overlapping layers so each upper piece lies over the one below, sending water down and out like roof shingles.
Sill pan
A tray of flashing under a window or door with a raised back and ends, catching any water that gets past the unit.