Step-by-step fix
Step 1: Confirm the kickout flashing is the real problem
- Look at the bottom end of the roof-to-wall intersection where the shingles meet the sidewall above the gutter.
- Check for a missing piece, bent metal, rust holes, or a flashing end that does not turn water out into the gutter.
- Look for water stains, swollen trim, peeling paint, or damp siding directly below that corner after rain.
- Make sure the gutter is present and not simply overflowing from a clog, because overflow can mimic a bad kickout flashing.
If it works: You have clear signs the kickout flashing is missing, damaged, or shaped wrong and water is not being kicked into the gutter.
If it doesn’t: If the flashing looks intact, clean the gutter and downspout first and watch the area during the next rain before taking siding apart.
Stop if:- The wall or roof edge feels soft or spongy.
- You see widespread rot, mold, or insect damage behind the siding.
- The roof is steep, high, wet, or otherwise unsafe to access.
Step 2: Set up the area and expose the lower roof-to-wall joint
- Wait for dry weather so the roof, siding, and sealants are not slippery or wet.
- Set the ladder on firm ground and position it so you can work without leaning sideways.
- Remove or loosen only the lowest section of siding or trim needed to reach the kickout area.
- Use a flat pry bar gently so you do not crack the siding or tear the weather barrier behind it.
If it works: You can see the lower step flashing area and have enough access to remove and replace the kickout piece.
If it doesn’t: If the siding will not loosen without breaking, remove a little more trim or fasteners so the area can come apart cleanly.
Stop if:- The siding is brittle enough that it is shattering instead of releasing.
- You uncover soaked sheathing or framing behind the wall covering.
Step 3: Remove the old kickout flashing and inspect the surfaces
- Lift the lower shingle edge and any overlapping flashing just enough to free the old kickout piece.
- Pull nails carefully if they pin the flashing in place, and keep track of where materials overlap.
- Slide out the damaged flashing without forcing it against the siding or roof covering.
- Inspect the exposed sheathing, trim, and underlayment area for rust stains, rot, or gaps that would keep the new flashing from sitting flat.
If it works: The old flashing is out and the surrounding surfaces are solid, dry enough to work on, and ready for the replacement.
If it doesn’t: If minor debris or old sealant is in the way, clean it off so the new flashing can sit flat and overlap properly.
Stop if:- Wood sheathing or trim crumbles when touched.
- The underlayment or flashing layers are so damaged that the repair extends beyond the kickout piece.
Step 4: Fit the new siding kickout flashing
- Dry-fit the new flashing at the bottom of the roof-to-wall joint before fastening anything.
- Make sure the vertical leg sits against the wall, the roof leg lies flat under the shingle edge, and the kicked-out end points water into the gutter.
- Trim the flashing only if needed for fit, using tin snips, and smooth any sharp edges.
- Check that the new piece overlaps with the existing flashing path so water sheds downhill instead of toward the wall.
If it works: The new kickout flashing fits cleanly, directs water toward the gutter, and does not buckle the siding or lift the shingles excessively.
If it doesn’t: If the piece does not direct water into the gutter, adjust the fit or use the correct size and shape before fastening it permanently.
Stop if:- The gutter placement leaves no way for the kickout to discharge into it.
- The replacement flashing cannot be installed without major roof or siding removal beyond this repair.
Step 5: Fasten and reassemble the siding and flashing layers
- Secure the flashing in the same general pattern as the original assembly, keeping fasteners where they will stay protected by overlapping materials.
- Re-lay the shingle edge and any overlapping flashing so each layer sheds water over the one below it.
- Reinstall the loosened siding or trim without driving fasteners so tight that the material binds or cracks.
- Apply a small amount of exterior sealant only where you disturbed a sealed joint or where a minor gap needs weather protection; do not rely on sealant as the main water control.
If it works: The new flashing is secured, the siding is back in place, and the assembly follows a top-over-bottom water-shedding pattern.
If it doesn’t: If the siding will not sit flat, back up and check whether the flashing is too tall, twisted, or trapped behind a fastener.
Stop if:- Reassembly leaves an obvious reverse lap where water can run behind the flashing.
- Fastening the area requires piercing exposed water-shedding surfaces that were not originally fastened there.
Step 6: Test the repair with water and after the next rain
- Run a gentle stream of water on the roof above the repaired area for several minutes, starting low and working upward.
- Watch to confirm water travels down the roof, hits the kickout flashing, and drops into the gutter instead of behind the siding.
- Check the wall below and the interior side of that area, if accessible, for any fresh moisture.
- Inspect the repair again after the next real rain to make sure the result holds under normal runoff.
If it works: Water is being directed into the gutter, the wall stays dry, and the repair holds during real weather.
If it doesn’t: If water still gets behind the siding, the problem may include step flashing, underlayment, gutter placement, or hidden wall damage that needs a broader repair.
Stop if:- You still see leakage behind the siding or inside the wall after the replacement.
- Water bypasses the gutter because of roof, gutter, or flashing layout issues you cannot correct safely from this repair alone.
Replacement Parts
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FAQ
What does a siding kickout flashing do?
It redirects water from the bottom of a roof-to-wall flashing run into the gutter. Without it, runoff can shoot behind the siding and soak the wall.
Can I just add caulk instead of replacing the flashing?
Usually no. Caulk can help seal a small disturbed joint, but it does not replace the shape and overlap needed to move water away from the wall.
How do I know the kickout flashing is installed correctly?
During a hose test, water should hit the flashing and visibly discharge into the gutter, not run behind the siding or down the wall face from behind trim.
Do I need to remove all the siding in that area?
Usually not. In many cases you only need to loosen the lowest section or nearby trim enough to access the bottom of the roof-to-wall joint.
What if I find rot behind the siding?
Stop and repair the damaged sheathing, trim, or framing before closing the wall back up. New flashing will not solve hidden structural or moisture damage by itself.