Quick Answer: A missing kickout flashing lets roof runoff pour behind your siding instead of into the gutter, and the damage stays hidden until the wall is opened. On a recent Des Moines job we found a wall that looked perfectly normal from the outside and rotted sheathing and framing behind it. The part that would have prevented all of it costs a few dollars. The repair can run a hundred times that or more. Here is what we found, and how we corrected it.
From the street, the wall looked fine. Clean siding, straight lines, nothing a homeowner would ever flag. That is the problem with a missing kickout flashing: by the time you can see it, the repair is already large. This is a real Des Moines-area home we worked on, documented as we opened the wall.
Andrew’s Roofing Company has repaired water damage across the Des Moines metro since 2008. In 18 years, missing kickout flashing is one of the most common hidden failures we find, and one of the most preventable.
What Is a Kickout Flashing?
A kickout flashing is a small metal or plastic diverter installed at the very bottom of a roof-to-wall intersection, right where the lower edge of a sloped roof meets a vertical wall above a gutter. Its only job is to kick water off the roof and into the gutter instead of letting it run down the wall behind the siding.
It is a small piece. On a finished home you might never notice it. But it sits at the one spot where a concentrated stream of roof water is aimed directly at the seam between your roof and your wall. Without it, that water has nowhere to go but behind the siding.
Why Is Kickout Flashing So Often Missing?
Because installing it correctly crosses three trades, and no single one owns it. The roofer, the siding installer, and the framer each touch that junction at different stages, and the flashing has to be layered in with the underlayment, the water-resistive barrier, the roofing, and the siding to actually work. When responsibility is split three ways, the detail falls through the cracks.
There is also a naming problem. Building codes describe what this flashing has to do without always using the words “kickout flashing,” so it is easy to overlook on a plan or an inspection. A crew that has never had the detail passed down to them often does not know to look for it.
The result is that we find missing kickouts on homes of every age across the metro, including newer builds that should have had one from day one.
Is Kickout Flashing Required by Code?
Yes. The International Residential Code has required a diverter at this junction since 2009. The current code language, in Section R903.2.1, calls for flashing to be installed to divert water away from “where the eave of a sloped roof intersects a vertical sidewall.” Iowa adopts the International Residential Code for one- and two-family homes, so the requirement applies here.
Worth knowing if you are buying or selling: a home inspector who flags “missing kickout flashing” on a report is pointing at a real code item, not a nice-to-have. The good news is that it can almost always be retrofitted by a roofing contractor without rebuilding the wall, as long as it is caught before water damage sets in.
How Do You Spot a Missing Kickout Flashing?
From the ground, look at the bottom of any roofline that ends against a wall, just above where a gutter starts. A proper kickout is a small flashing that turns out away from the wall, nudging water into the gutter. If you see nothing there, or you see a blob of caulk or sealant doing the job instead, that is a red flag.
The other tell is on the wall below that junction: vertical staining, algae streaks, blistered paint, or soft, wavy siding. But here is the honest part, and it is the reason this problem is so costly. There is often no sign at all. The water runs behind the siding, not down its face, so the wall can look perfect while the sheathing behind it quietly rots. That is exactly what happened on this job.
A caulk-and-hope patch at the junction on another home we inspected. Sealant is not a substitute for a kickout flashing. It fails, and the water goes right back behind the siding.
A caulk-and-hope patch at the junction on another home we inspected. Sealant is not a substitute for a kickout flashing. It fails, and the water goes right back behind the siding.
What We Found When We Opened the Wall
Once we pulled the siding, the scale of it showed up fast. Water had been getting behind the wall long enough to work its way well up from the junction, so the repair area was far larger than the little flashing that would have prevented it.
Behind the siding, the sheathing told the story. The oriented strand board had absorbed so much water that it had lost its structure entirely, delaminating into wet, crumbling layers. Sheathing in that condition cannot hold a fastener or carry any load. It has to come out.
And the damage did not stop at the sheathing. When we cut the failed board away, the water had reached the framing behind it. The structural wood was blackened and deteriorated, and the insulation in the cavity was soaked through. This is the part a homeowner never sees and never suspects, because everything on the outside looked normal right up until we opened it.
This is why we tell homeowners that a missing kickout is not a small problem waiting to happen. It is often a large problem already happening, out of sight.
The Real Cost of a Missing Kickout Flashing
Here is the math that matters. The flashing itself is one of the cheapest parts on your entire house. Installed correctly during a roof or siding job, it adds almost nothing to the cost.
Left out, it can lead to a repair that runs a hundred times that price or more, because you are no longer paying for a small flashing. You are paying to remove siding, tear out rotted sheathing, replace damaged framing, dry and re-insulate the cavity, install a proper water-resistive barrier, add the flashing that should have been there all along, and put the wall back together. In the worst cases, the damage reaches interior walls and finishes too.
That is the whole argument for getting this detail right the first time. A few dollars of flashing and careful sequencing prevents a repair that can climb into the thousands.
How We Corrected It
Fixing a wall like this is not just tacking on the missing part. Once the rotted material was removed, we rebuilt the junction the way it should have been done originally, layering it so water is directed out and away instead of in.
That means new sheathing over sound framing, a fresh water-resistive barrier lapped in the right order, flashing tape sealing the three-way corner where roof, wall, and fascia meet, and a proper kickout at the bottom of the run to send water where it belongs. Done this way, the junction sheds water for the life of the wall. In our Iowa climate, that layering matters even more, because the same junction takes a beating from ice and freeze-thaw every winter.
Should You Have Your Home Checked?
If any roofline on your home ends against a wall above a gutter, it is worth a look, especially if you have never confirmed a kickout is there, if you see staining below that junction, or if a home inspection flagged it. Catching a missing kickout before water gets behind the siding is the difference between a quick retrofit and the repair you just saw.
If you already have a leak or suspect hidden water damage, our guide on why your roof might be leaking walks through the other common sources. And for how this same junction ties into your gutters and winter ice, see our post on gutters and kickout flashing.
Get a Free Inspection From a Des Moines Roofer Who Knows Where to Look
Most water damage we repair was preventable, and it usually traces back to a small detail like this one that was skipped or done wrong. We inspect these junctions for free, tell you plainly whether your kickouts are there and doing their job, and if something needs correcting, we show you exactly what we see before any work begins. No fear-selling, no pressure, just an honest look.
Andrew’s Roofing Company is a family-owned, GAF Master Elite Contractor that has protected Des Moines metro homes since 2008, serving Des Moines, Ankeny, Waukee, West Des Moines, Urbandale, Altoona, Clive, Johnston, Norwalk, Pleasant Hill, Indianola, Adel, Bondurant, and Carlisle.
Explore our roofing services, learn more about our team, and contact us today for a free inspection.
