Headwall flashing is used where the top edge of a sloped roof meets a vertical wall. It helps keep water from running behind the wall covering or into the roof assembly.
Why It Matters
Roof-to-wall transitions are leak-prone because water changes direction there. Headwall flashing gives water a path back onto the roof surface instead of behind siding or trim.
Common Problems
Problems include undersized metal, missing end dams, exposed nails, siding installed too tightly, heavy reliance on caulk, and flashing that does not integrate with underlayment.
Building Codes & Industry Standards
Roof-to-wall flashing should follow roofing manufacturer instructions and coordinate with wall cladding requirements. It is a system detail, not just a piece of metal tucked behind siding.
Exterior Echelon Notes
Exterior Echelon reviews headwall flashing during roofing and siding work because both systems need to shed water together.
