Central Roof Repair · Code & Detailing
Kick-out flashing in Kentucky sits in an odd place: the residential code requires exactly what a kick-out does, and never uses the words “kick-out flashing.” That gap is why a homeowner can be told, truthfully, that the part is not named in the code — and be misled, because the function it performs is required.
Does the Kentucky residential code require kick-out flashing?
It requires the function and not the name. The code demands a flashing that diverts water away from the point where a sloped roof’s eave meets a vertical sidewall — which is the job a kick-out does.
Kentucky’s residential code is the 2015 International Residential Code, adopted by reference. 815 KAR 7:125 states that “the 2015 International Residential Code for One (1) and Two (2) Family Dwellings (IRC) shall be the mandatory state residential building code for all single-family dwellings, two (2) family dwellings, and townhouses constructed in Kentucky, except that the Kentucky amendments in the 2018 Kentucky Residential Code shall supersede any conflicting provision in the 2015 IRC.” That regulation was last amended effective December 3, 2024.
Inside that code, section R903.2.1 (Locations) reads: “Flashings shall be installed at wall and roof intersections, wherever there is a change in roof slope or direction and around roof openings. A flashing shall be installed to divert the water away from where the eave of a sloped roof intersects a vertical sidewall.” Read it twice. The second sentence describes a kick-out precisely — the eave, the vertical sidewall, the diversion — without naming the part, setting a length, or stating an angle. Text read in the Kentucky Residential Code Chapter 9 on October 4, 2026.
Kentucky’s code names the job, not the part. A roofer can meet the letter of it badly and still have met it.
What is the difference between that and a code that names the part?
A named requirement is prescriptive and arguable; a functional requirement is not. Some states amended the same IRC to add a section that uses the words.
Minnesota, working from the same 2015 IRC, added section R903.2.2 titled Kick-Out Flashing/Diverter: “A kick-out flashing shall be installed where the lower portion of a sloped roof steps within the plane of an intersecting wall cladding, in such a manner as to divert or kick out water away from the assembly.” Kentucky did not add that section. The comparison is mine, drawn from the two states’ adopted texts, and the point is not that Kentucky’s rule is weaker — a functional requirement is harder to wriggle out of, not easier. The point is that an inspector in Kentucky is checking whether water is diverted, not whether a part with a particular name is present.
How does the sidewall flashing section interact with it?
It sets the only dimensions in the detail. Base or step flashing against a vertical sidewall must be at least 4 inches high and 4 inches wide, and must direct water away from that wall.
Section R905.2.8.3 (Sidewall flashing) reads: “Base flashing against a vertical sidewall shall be continuous or step flashing and shall be not less than 4 inches (102 mm) in height and 4 inches (102 mm) in width and shall direct water away from the vertical sidewall onto the roof or into the gutter.” So Kentucky’s code gives you two independent diversion duties at the same intersection: step flashing that pushes water out of the wall plane the whole way up the slope, and a flashing at the bottom of that run that keeps the collected water from running straight into the cladding at the eave.
| Section | What it requires | Dimension stated |
|---|---|---|
| R903.2.1 | A flashing that diverts water away where a sloped roof’s eave meets a vertical sidewall | None |
| R905.2.8.3 | Continuous or step base flashing against a vertical sidewall, directing water onto the roof or into the gutter | Not less than 4 in. high and 4 in. wide |
| R905.2.8.5 | Drip edge at eaves and gables of shingle roofs | Adjacent pieces lapped at least 2 in. |
Why does the missing detail show up as a wall problem, not a roof problem?
Because the water lands behind the cladding, not on the ceiling. The stain appears on a wall below the roof-wall intersection, often a storey down, and nothing on the roof looks wrong.
That is the whole diagnostic value of knowing this detail exists. A roof plane that sheds into a sidewall concentrates the runoff of the entire plane into a few inches of wall at the bottom of the step-flashing run. If nothing turns that stream outward, it goes behind the siding or brick, and from there into sheathing and framing, where it does its damage out of sight and over years. The symptom pattern — a wall stain or soft trim below a roof-to-wall junction, with a dry attic and sound shingles — points at the bottom of the step run before it points at anything else.
In our own work the useful habit is to look at this detail from the ground before going up: stand where the eave meets the wall, look at the last few inches of flashing at the bottom of the step run, and ask whether anything there turns water out and away from the cladding. That is a two-minute look, and it is general craft rather than a claim about any particular house — we describe method here and never a customer’s property or a job we have not performed.
Where this sits with the rest of the flashing work
It is the bottom end of a detail we already cover further up the slope. Valley and wall flashing repair covers the run itself, chimney flashing covers the other common vertical interruption, and the slope ladder in Kentucky’s code covers which covering the code permits on each plane.
Does Kentucky’s code require a kick-out when re-roofing an existing house?
The Kentucky text we read does not contain a re-roofing exception for this detail, because it does not contain a separately named kick-out section at all — the diversion requirement in R903.2.1 is general. Some other states added both the named section and an exception. Confirm the scope of your permit with the local building official, since Kentucky permitting and inspection is administered locally.
How long should the diverter be?
Kentucky’s code states no length for it. The only dimension in the sidewall detail is the 4-inch minimum height and width for base or step flashing in R905.2.8.3. Anyone quoting you a Kentucky code minimum length for a kick-out is quoting a different state’s amendment or a manufacturer’s instruction, not this code.
Which edition of the code applies in Kentucky right now?
815 KAR 7:125 makes the 2015 IRC the mandatory state residential code, with the Kentucky amendments in the 2018 Kentucky Residential Code superseding any conflicting 2015 provision. The regulation’s most recent amendment took effect December 3, 2024. Read the current regulation at the link above rather than relying on a summary.
Last updated: October 4, 2026
By Marcos Gil, REALTOR® — Keller Williams Commonwealth · KY Real Estate License No. 296259 · Call or text (859) 310-1209.
Central Roof Repair is owned by Marcos Gil, who also publishes marcosgilrealty.com and forsalelexingtonky.com. This is general information about Kentucky’s adopted residential code, current as of October 4, 2026 — not legal, engineering or code-official advice, and not a representation about any particular roof. Code editions and local amendments change; verify with your local building official and the Department of Housing, Buildings and Construction.
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