Headwall flashing repair fixes the metal joint where the top edge of a sloped roof runs straight into a vertical wall, such as where a first-floor roof slopes up to meet a second-story wall. When that flashing rusts, pulls loose or was never lapped correctly, water runs down the wall and behind the roof instead of onto it.
Seeing a stain on a ceiling right below a wall above the roof? Book your roof diagnosis online and we will check the headwall before more water gets into the framing.
What headwall flashing does
Every time a roof meets a wall, there is a seam that roofing material alone cannot seal. Headwall flashing is a continuous piece of bent metal that sits under the wall finish on one leg and laps over the top course of roofing on the other. Rain running down the wall hits the flashing and is carried out onto the roof surface, where it drains normally.
Headwall flashing vs. step flashing
The two get confused, but they protect different joints. Headwall flashing is used where the wall runs horizontally across the top of a roof slope. Step flashing is used where a wall runs up the side of a slope, in overlapping pieces woven with each course of shingles or tile. Many homes have both on the same wall, meeting at the corner, and that corner is a frequent leak point. Our guide to step flashing repair covers the sidewall side of the story.
The counterflashing layer
On stucco and masonry walls, a second piece called counterflashing covers the top edge of the headwall flashing so water cannot slip behind it. If the counterflashing is missing, cracked out of the stucco or bent away from the wall, the main flashing can be perfectly sound and the joint will still leak.
Why headwall flashing fails on Orange County homes
- Corrosion: Salt air near Huntington Beach, Laguna Beach and San Clemente speeds up rust on galvanized flashing, especially where it is buried in damp stucco.
- Stucco movement: Stucco shrinks, cracks and shifts. When the wall finish moves, it can open a gap at the top of the flashing.
- Sealant used instead of metal: A bead of caulk where the roof meets the wall looks tidy at first, then dries, cracks and lets water in, often within a few seasons of sun.
- Remodel shortcuts: Additions, window replacements and re-stucco projects sometimes cover or cut the original flashing without replacing it. Our article on stucco wall and roof intersection leaks explains how wall work affects the roof below.
- Tile roof challenges: On clay or concrete tile, headwall flashing has to be shaped to follow the tile profile, or paired with a flexible apron that is dressed over it. If it sits flat on the high points or is too short, wind-driven rain gets under it.
Signs you need headwall flashing repair
Headwall leaks usually show up on the room directly under the roof-to-wall junction, but water can travel along a beam first. Watch for:
- Ceiling stains near an exterior wall where an upper story sits back from the lower roof.
- Cracked, stained or bubbling stucco right above the roofline.
- Rust streaks on the wall or visible gaps between the flashing and the wall.
- Dried, cracked sealant along the roof-to-wall line.
- Soft or discolored roof decking when viewed from the attic below the junction.
Leaks that only appear in heavy, wind-driven storms are common with headwall problems, because the water has to be pushed up and over the flashing leg.
How a proper headwall flashing repair is done
A lasting repair replaces the failed detail rather than covering it. While the exact steps depend on the roof and wall type, the work usually follows this order.
Opening the joint
The top course of roofing below the wall is lifted or removed, and the wall finish just above the flashing may be cut back so the full leg of the flashing can be inspected and replaced. This is the step most quick patch jobs skip.
Repairing decking and underlayment
Wet or rotted decking is replaced, and new underlayment is turned up the wall behind the flashing for a second line of defense. As "The No-Felt Company," Rescue Roofer never uses felt underlayment.
Installing new flashing and counterflashing
New headwall flashing is set to lap correctly over the roofing, and counterflashing or a reglet is installed so the top edge is covered. Where the headwall meets a sidewall, the corner is carefully detailed, and a kickout flashing is added at the lower end of any sidewall so runoff is pushed into the gutter instead of down the wall.
Finishing the wall and roof
The roofing is reset or replaced to match, and the wall finish is patched so it sits just above the roof surface rather than on it. That small gap keeps the stucco from wicking water back into the joint.
Booking headwall flashing repair with Rescue Roofer
Headwall work is handled by our roof repair and restoration team. A T.E.A.M. Certified technician traces the leak from both the roof and the attic, and you get a clear explanation of the cause and the recommended repair before work starts. Our "Warehouse on Wheels" trucks arrive stocked with flashing and roofing materials, so the crew is ready to start once the scope is agreed.
Rescue Roofer is a licensed roofing contractor, St. Lic #1137524, serving Orange County since 1993, with offices from Yorba Linda to San Clemente and in San Pedro.
Frequently asked questions
Can headwall flashing be repaired without removing stucco?
Sometimes a damaged counterflashing can be replaced with minimal wall work, but if the main flashing leg is rusted or too short, a small strip of stucco usually has to be cut back to do the job correctly.
Is caulking the roof-to-wall joint enough?
No. Sealant can be a temporary measure during an active leak, but it is not a substitute for properly lapped metal flashing and will fail in Southern California sun.
How do I know if it is the headwall or the roof itself?
Leaks that track along the junction line, show up in windy storms and appear near an upper wall point to the headwall. An inspection confirms it before any work begins.
A failed headwall lets water into the exact spot where roof, wall and framing meet, so it pays to act early. Tell us what you are seeing and we will find the source and fix it with the right flashing detail. Book your roof diagnosis online or call 1-888-346-7663.