Step and kick-out flashing: the wall junction that sends water into the wall
This is one of the most common defects a home inspector finds, and it hides in plain sight: a single missing piece of bent metal, four inches wide.
Anywhere a roof slope runs up against a sidewall (a dormer, an attached garage, a two-story addition), the junction is flashed with a series of individual L-shaped pieces called step flashing. One piece is woven in with each course of shingles as it climbs the wall.
Done properly, every piece laps over the one below it and under the siding above it. So water is always handed downhill, the same principle as every other flashing detail on a roof. Where that run of step flashing ends, at the bottom, is where most of these junctions actually fail: a small diverter called kick-out flashing is supposed to be there. And on a huge number of houses it simply isn't.
What step flashing gets wrong
The step-flashing kit itself fails in a familiar way: it was substituted with a single continuous strip of metal. Or with sealant, instead of individual pieces woven into each course.
A continuous strip can't accommodate the roof and the wall settling and moving independently. And it turns every seam into a place for water to work its way behind. As on a chimney, a bead of sealant along a roof-to-wall junction is a strong sign that someone has already been patching a flashing problem rather than fixing it.
What a kick-out actually does
Water running down a step-flashed wall junction is being carried, course after course, toward the bottom of that run. At the bottom, the roofline usually ends and a gutter begins. Without a diverter, all of that water reaches the end of the step flashing and keeps going: not into the gutter. But straight down behind the siding, into the wall assembly below.
A kick-out flashing is a small, angled piece set at that exact point. It physically redirects the water outward, off the wall and into the gutter, instead of letting it continue past the roofline.
Why it's so often missing
A kick-out is a few inches of bent metal at a single point. It is easy to leave out and easy for an inspector or a homeowner to overlook, because from the ground the roofline and the wall look continuous either way. For exactly that reason it has become one of the more frequently cited defects in residential construction and inspection reports. It's cheap and small, it's invisible once the siding is on, and its absence does nothing dramatic for years.
What the damage looks like once it shows up
Because the water is going behind the siding rather than dripping visibly, the first signs are rarely on the roof at all.
- A vertical stain or dark streak on the siding, starting right where the roofline meets the wall and running down.
- Paint or siding failing in that one spot long before the rest of the wall shows any wear.
- Soft or spongy siding, or a section that flexes when pressed near that corner.
- Interior staining or soft drywall on the same corner, one floor down, if the water has been tracking behind the wall for a while.
The entry point and the damage can be feet apart. The water enters at the roofline and tracks down inside the wall cavity before it shows up. That makes this one of the easiest leaks in the whole flashing category to misdiagnose from the wrong evidence.
Step flashing versus kick-out: not the same fix
It's worth keeping these separate, because they fail differently and get treated differently. A step-flashing failure along the run shows up as water appearing partway up the wall junction, often at a specific course.
A missing or failed kick-out shows up specifically at the bottom of the run, right where the roofline meets the gutter line. And it's the one that sends water into the wall itself rather than just onto the roof. A roof can have perfectly good step flashing all the way up and still cause serious hidden damage from one missing kick-out at the bottom.
What you can check safely, and what to leave alone
From the ground, look specifically at the point where a roof edge meets a wall. Not partway up the slope. But right at the corner where the gutter starts. A visible gap between the end of the step flashing and the gutter, with no angled piece bridging the two, is the sign to look for.
Staining on the siding directly below that point backs it up, especially if it doesn't match weathering anywhere else on the wall. This is not a repair to attempt from a ladder. Correcting it usually means pulling back a section of siding to install the diverter properly. That is roofing and siding work done together, not a patch applied from outside.
Frequently asked questions
What is kick-out flashing?
A small, angled piece of metal placed at the bottom of a roof-to-wall junction, where a sloped roof edge meets a sidewall. Its job is to redirect water running down the wall junction outward into the gutter, instead of letting it continue past the roofline and behind the siding.
How is kick-out flashing different from step flashing?
Step flashing is the series of individual pieces woven into each shingle course as the junction climbs the wall. Kick-out flashing is the single piece at the bottom of that run that diverts the water out and away once it reaches the end of the step-flashed section.
Why is a missing kick-out such a common problem?
It's a few inches of bent metal at one specific point, invisible once the siding is installed, and its absence doesn't cause a dramatic leak: the water tracks behind the siding for years before staining or soft wood becomes obvious. That combination makes it one of the most frequently cited defects in residential inspections.
What does the damage from a missing kick-out look like?
Usually a vertical stain or streak on the siding starting right at the roofline, paint or siding failing in that one spot before the rest of the wall, or soft, spongy siding near the corner. Interior staining on the same corner one floor down can appear if it's been tracking for a while.
Can I fix a missing kick-out myself?
We wouldn't recommend it. Installing one correctly usually means pulling back a section of siding, which is roofing and siding work done together, and the corner itself is exactly the kind of roof edge this site never suggests working from a ladder to inspect or repair.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- NRCA. National Roofing Contractors Association
- US OSHA. 1926.501 — Duty to have fall protection (OSHA)