Kick-Out Flashing and Headwall Flashing:
Two Small Pieces of Metal That Keep Water Out of Walls
Where a roof edge runs into a wall, and where siding sits over a window, rain needs a way out. Both jobs belong to a bent piece of metal most people never notice.
Of the 269 houses in Russ’s recent reports, 97 had a kick-out or headwall flashing finding. About 50 were missing kick-out flashing or had one too small to do the job. About 55 had no headwall flashing over the windows and doors. Portland, Vancouver, Beaverton, Gresham, Battle Ground: it doesn’t care what decade or what neighborhood.
These two pieces of metal cost very little. What they protect is the wall.
Real Inspection Photos
Flashing Findings From Russ's Inspections
Missing kick-outs, undersized kick-outs and headwall flashing problems from Russ's recent reports.
-
A roof edge ending against brick with no kick-out flashing to turn the water into the gutter. -
A kick-out that was too small to divert the water running down the roof-to-wall joint. -
Headwall flashing over a door that wasn't tucked behind the siding, so water could run behind it. -
Headwall flashing sealed with caulk, which blocks the drainage it's there for. -
Step flashing installed over the shingles instead of under them.
Where kick-out flashing goes
Picture a garage roof that runs into the side of a two-story wall. Where the roof meets the wall, step flashing runs up the joint, one L-shaped piece per shingle course. Water running down the roof hits that joint and follows the step flashing down to the bottom of the roof.
At the bottom, it has two choices. With a kick-out flashing, a small angled diverter, it gets turned out into the gutter. Without one, it runs straight off the end of the step flashing onto the wall, behind the end of the gutter, and down the siding. Some of it goes behind the siding.
Russ’s report wording: kick-out flashing is important for directing water away from the siding and the wall below. In Vancouver, he found kick-outs that were too small and had already let moisture into the wall. In Lake Oswego, an undersized kick-out came with water staining on the stucco below it. In Beaverton, a lower roof and gutter ended against a brick chimney with no kick-out at all.
Where the damage shows up
The damage from a missing kick-out builds slowly and out of sight. Water gets into the corner behind the siding during every storm. On a wall with a good drainage plane it may dry out. On stucco, or on a wall with a weak weather barrier, it sits in the sheathing.
From the outside, look below the bottom corner of the roof: dark streaks, peeling paint, swollen trim, siding that’s soft or bulging. The stucco and EIFS post covers why this spot is a classic leak point on stucco houses. Russ can point to the clues on the surface. He can’t see inside the wall, and moisture readings only tell part of the story.
Headwall flashing over windows and doors
Headwall flashing is a strip of metal bent into a Z. It sits on top of the trim over a window or door, tucks up behind the siding above, and laps down over the face of the trim. Water running down the siding hits it and is pushed out, away from the top of the window.
Other flat trim on the wall needs the same kind of cap. The post on flashing at corbels, belly bands and horizontal trim covers those spots.
This was the single most common flashing finding in Russ’s reports. In a lot of houses, it was never installed. His reports note when that’s typical for the age of the house (a 2000-built Portland house, a Happy Valley house, a Battle Ground house). They also note what that means: the sealant along the top of the trim is now the only thing keeping water out, and it has to be maintained.
In Gresham, the headwall flashing was there but wasn’t tucked behind the siding, so water could run down behind the flashing instead of over it. In Beaverton, someone had caulked the headwall flashing shut, which blocks the drainage it’s designed for.
Step flashing and other roof-to-wall problems
Kick-outs are the end of the roof-to-wall joint. The rest of it has its own mistakes. In a Portland house, step flashing was installed on top of the shingles instead of under them. In The Dalles, the step flashing had no sidewall flashing and was sealed straight to the siding. In another Portland house, a roof slope ran directly into a vertical wall with no cricket or diverter to send the water anywhere.
Siding also needs a gap above the roof shingles so it doesn’t sit in the water running down the step flashing. The post on siding clearance covers that one.
What Russ checks
He walks the roof when it’s safe, or uses a drone when it isn’t, and looks at every roof-to-wall joint, kick-out and step flashing he can see. From the ground, he looks for headwall flashing over windows and doors and checks the siding and trim below roof edges for staining, soft spots and damage. He uses a moisture meter and thermal imaging at suspect spots. He doesn’t remove siding, so what’s behind it stays unknown. Missing or failing flashing gets a recommendation for a qualified roofing or siding contractor.
- Find every spot where a lower roof edge ends against a wall
- Look for a small angled diverter at the bottom, aimed into the gutter
- Check the siding below that corner for stains, peeling paint or soft trim
- Look above each window and door for a metal lip over the top trim
- Look for caulk smeared over flashing edges
Missing headwall flashing over windows and missing or undersized kick-out flashing were among the most common exterior findings in Russ’s reports. Both are small, inexpensive parts. The cost comes from the water they would have kept out of the wall, so look below every roof-to-wall corner.
For the rest of the outside of the house, the guide to what to look at on the exterior before you make an offer covers siding, trim and drainage. The drip edge post covers the flashing at the roof edge itself. To set up an inspection, you can book online.
Flashing FAQ
