Flashing
Sheet material installed at joints and transitions in the building envelope to direct water away from vulnerable intersections.
What is Flashing?
What is Flashing?
Most water intrusion happens at transitions rather than in the field of a roof or wall, which makes flashing one of the highest-value things an inspector examines. Common locations are roof-to-wall intersections, chimneys (which need base, step and counter flashing plus a crown), valleys, skylights, deck ledgers, and window and door heads. Step flashing woven into each shingle course is correct; a continuous bent strip caulked to the wall is a frequent shortcut that eventually leaks. Reliance on sealant in place of properly lapped flashing is a defect worth stating plainly, because sealant is maintenance and flashing is construction.