The Small Piece of Flashing That Keeps a Wall Dry

A dark patch below the end of a roof, peeling paint beside a gutter, or damp drywall near an outside wall can begin with one missing piece of metal. It is called kick-out flashing. It belongs where a sloped roof meets a vertical wall and ends at the gutter. Its job is to push water away from the wall and into the trough. Without it, every rain can send a narrow stream behind the siding, trim, house wrap, or brick veneer.

Town roofing

Chesterfield has plenty of roof-to-wall intersections. They appear beside attached garages, under second-story walls, around dormers, and where additions meet the original house. Many of these intersections end directly above a gutter. That ending point is where kick-out flashing matters.

Water running down a shingle roof follows the step flashing installed along the wall. Each piece of step flashing overlaps the piece below it, moving water toward the eave. At the bottom, the kick-out turns that water outward. The finished piece should project far enough to clear the wall covering and discharge into the gutter rather than behind it.

A missing kick-out may not create an obvious ceiling leak. Water can stay inside the wall assembly, where it wets sheathing, framing, insulation, or the back of gypsum board. On a brick house, the stain may appear below the roof edge or near a window rather than at the actual entry point. Brick veneer sheds much of the rain that hits it, but it is not the waterproof layer of the wall. Water that is directed behind the veneer still has to drain somewhere.

The warning signs are usually concentrated near the lower end of the roof-wall joint:

• Paint or trim deterioration immediately below the gutter end.
• Swollen siding, soft wood, or dark streaks at the corner.
• Efflorescence, staining, or persistent dampness in nearby brickwork.
• A recurring interior stain close to an exterior wall or window opening.
• Wet sheathing found behind siding even though the shingles above look intact.
• Water marks that become more noticeable during wind-driven rain.

These symptoms do not prove the kick-out is the only problem. The step flashing could be short, rusted, punctured, or installed on top of the shingles instead of woven between courses. The wall covering might also have been installed tightly against the roof, leaving no practical way to inspect the flashing. A roofer has to trace the entire intersection rather than attach a small metal tab to the visible corner and call the leak repaired.

Chesterfield weather makes a weak detail less forgiving. Wind-driven spring rain can push water against the wall. Summer storms can deliver a large volume in a short period. During winter, water held in a narrow gap can freeze, expand, and open the joint further. Ice damming at the eave can also keep water near a roof-wall termination longer than it would remain there during an ordinary rain.

Gutters sometimes hide the defect. If the gutter end cap presses tightly against the wall, the roofer may need to loosen or remove a section to see whether the roof flashing actually directs water into the trough. Caulk smeared between the gutter, siding, and shingles can conceal the opening for a while. Caulk does not replace the layered drainage path. It ages, pulls away, and becomes another joint that must remain watertight.

What it costs

There is no useful flat price for kick-out flashing because access and surrounding materials control the work. A correction on a low garage roof with ordinary lap siding is different from a repair beneath stucco, masonry, or a second-story wall. The visible metal is inexpensive. Reaching the flashing and rebuilding the layers around it can be the larger part of the job.

A written repair scope should identify what must be opened. That may include shingles at the lower sidewall, the gutter end, trim, siding, or a small section of wall covering. It should also say whether existing step flashing can remain or whether the pieces will be replaced. If wet roof decking or wall sheathing is possible, the proposal should state how additional carpentry will be priced before the work begins.

Some repairs remain local. The roofer removes several shingles, exposes the lower step flashing, installs a formed kick-out, restores the water-resistive layers at the wall, and reconnects the gutter. Other repairs grow after the wall is opened because repeated wetting has softened sheathing or framing. A stain that has appeared only recently does not establish when the hidden wetting started.

Replacing the entire roof is not automatically required. If the field shingles still have usable life and compatible shingles can be lifted without breaking, a focused repair may make sense. Repair becomes less predictable on an old three-tab roof. Once three-tab shingles are brittle, lifting courses to reach step flashing can crack tabs and disturb a wider area. At that stage, the condition of the whole roof matters as much as the size of the visible leak.

If roof replacement is already planned, the roof-wall ending should be included in the scope before tear-off. This is the time to expose the joint, inspect the sheathing, install step flashing correctly, and form a kick-out that clears the finished wall. Keys Roofing installs Atlas and Malarkey shingles, but the shingle selection does not correct a poorly detailed sidewall. The flashing layout has to be addressed separately in the written scope.

A permit may or may not be required for a limited repair, depending on the exact work and the authority responsible for the address. Chesterfield properties can involve city requirements as well as the municipal permit structure used across St. Louis County. The contractor should identify the applicable permit desk instead of assuming that every county address follows the same process.

What to ask

Ask the roofer to show you where the step flashing ends and where the water is supposed to go. A photograph taken from the roof edge is more useful than a general statement that the area needs sealant. You should be able to see whether metal turns away from the wall and reaches over the gutter line.

Then ask these specific questions:

1. Will you remove shingles to inspect the lower step flashing? The condition of the visible corner alone does not reveal how the pieces above it were layered.
2. Does the wall covering have to be opened? A kick-out must connect to the drainage plane behind siding, stucco, or veneer. Surface metal without that connection may still let water enter behind the wall.
3. Will the kick-out discharge inside the gutter? Water should not run between the gutter end cap and the wall.
4. How will you handle damaged sheathing? The proposal should provide a unit rate or another written method for approving concealed wood work.
5. What will be photographed? Ask for images before opening, after the flashing is exposed, after damaged material is removed, and after the new layers are installed.
6. Will the repaired shingles match the existing roof? Missouri has no matching statute for roofs. Whether broader replacement is available under an insurance policy depends on that policy's wording, not a statewide matching rule.
7. How will the siding or masonry joint be restored? The roofer should explain which trade will complete any wall work that falls outside the roofing scope.

Be cautious if the proposed repair consists only of roofing cement over the outside corner. Sealant can be part of a properly assembled detail, but it should not be the only thing steering roof runoff away from the wall. The durable fix uses overlapping materials so gravity carries water outward even after an exposed bead of sealant has aged.

If you cannot safely see the roof-wall ending from the ground, do not climb onto the roof to inspect it. Ask for close photographs and a written explanation of the water path. Keys Roofing can inspect the intersection, document what is visible, and put the proposed repair scope in your hands. To schedule an inspection in Chesterfield, call (314) 220-2333.