Kickout Flashing Details for Burnaby Stucco Walls

Kickout flashing is a small, angled piece of metal at the bottom of a roof-to-wall junction. It sends water into the gutter instead of down the face of your stucco. On a Burnaby asphalt shingle roof, the detail that matters is the order of the layers: the kickout goes in first, the step flashing laps over it, and the wall membrane laps over both. Get that order wrong, or leave the kickout out, and a wet fall can push a concentrated stream of water behind the stucco, where you won’t see it for years.

This guide is for Burnaby homeowners, strata councils and property managers with a sloped roof that ends against a stucco wall. That means townhouse blocks, a garage roof tucked against a two-storey wall, or a dormer cheek wall. We cover how the detail is built, what the standards say, how to spot a missing or failed kickout, and what a proper repair involves.

TL;DR

• A kickout (diverter) flashing sits at the bottom end of a roof-to-wall intersection and throws runoff into the gutter, away from the cladding.
• Layer order is the whole game: kickout first, step flashing lapped over it by at least 4 inches (100 mm), then the wall membrane over the top.
• On stucco, the diverter needs a sealed 3/8 inch (10 mm) joint around it, and the stucco must not run into the flashing or gutter.
• Stains, soft stucco, cracking or a gutter that overflows at the wall end are the early signs of a missing or poorly formed kickout.
• Retrofitting means opening up the wall edge and the roof edge, so it is a job for a roofer who also understands the wall assembly.

Table of Contents

• What kickout flashing does at a stucco wall
• The layer order, step by step
• Detailing the kickout where it meets stucco
• Common failures we look for in Burnaby
• Signs you may have a missing or failing kickout
• Adding a kickout to an existing roof
• Questions for your roofer before work starts
• Our perspective
• Have the junction checked
• FAQ
• Sources

What kickout flashing does at a stucco wall

Where a sloped roof runs down against a vertical wall, rain follows the roof slope and meets the wall edge. Step flashing handles the water along the run. At the very bottom, where the roof ends but the wall keeps going, all of that water arrives in one spot. InterNACHI describes kickout flashing as a diverter that moves rainwater away from the cladding and into the gutter, and calls it critical where the wall continues past the lower roof edge and gutter.

Picture a garage roof meeting the side of a two-storey house. Every drop that lands on that roof slides toward the corner. Without a kickout, the water has two options: run into the gutter, or run down the wall. In a heavy Lower Mainland downpour, it takes both. The kickout makes sure the gutter gets the lot.

The same logic applies where a gutter ends against the side of a stucco-clad chimney. InterNACHI’s inspection guidance gives both the garage-roof and the stucco chimney stack example.

Why stucco makes this detail less forgiving

Stucco is a hard, continuous cladding. It doesn’t shed water like lapped siding, and it hides trouble well. Inspection guidance notes that newer claddings including stucco can mask evidence of water intrusion for years. Old cedar siding would peel and stain quickly. Stucco often looks fine until the sheathing behind it is soft.

That is why the kickout on a stucco wall is not a nice-to-have. It is the difference between water leaving the wall edge and water being poured at a single point on the wall.

The layer order, step by step

The U.S. EPA’s Building America Solution Center publishes a sequence for step and kickout flashing that matches what good roofers do on shingle roofs everywhere. It is written for American codes, but the physics of water do not change at the border. In plain terms:

1. Start with the kickout. A seamless, one-piece, non-corrosive diverter is the first piece of step flashing at the bottom of the run.
2. Slide it up the roof plane until its starter trough stops at the shingle starter strip. It sits flat on the roof and tight to the sidewall.
3. Fasten and seal it to the roof deck and starter strip. It is not fastened to the sidewall, because the wall and roof move differently.
4. Lap the first shingle and the first piece of step flashing over its up-slope edge, with at least 4 inches (100 mm) of overlap onto the diverter.
5. Continue up the wall with the remaining step flashing, counter flashing where needed, and shingles.
6. Apply self-adhesive flashing membrane over the top edge of the wall flashing, the diverter and the house wrap.
7. Lap the wall’s water-resistive barrier over the flashing, so each layer sheds onto the one below it.
8. Finish the cladding, which in our case means the stucco system.

The principle behind all eight steps is shingle-fashion lapping: the upper layer always laps over the lower one so water can never run behind the layer beneath. Building science writing puts it simply. Gravity drives drainage, so flashings need to direct water down and then out, and they need to be tied into the wall’s drainage plane.

Sizes and angles worth knowing

• Upper leg: the EPA guidance says step flashing should run at least 4 inches (100 mm) up the wall and at least 4 inches out along the roof deck, based on the 2015 U.S. residential code.
• Metal: where the flashing is metal, that same guidance cites galvanized steel at least 0.019 inches thick.
• Diverter angle: InterNACHI says the angle of the diverter should never be less than 110 degrees, and the bottom seam must be watertight.
• Size: the kickout must be large enough to handle expected storm flows. A tiny kickout in a big downpour will be overtopped.

These figures come from U.S. guidance. For work in Burnaby, the building code in force and the cladding manufacturer’s details are what you build to, and we explain how stucco fits in below.

Detailing the kickout where it meets stucco

Stucco adds two jobs to the standard roofing sequence: how the stucco terminates against the diverter, and how the membrane behind it is lapped.

The joint around the diverter

A Canadian stucco manufacturer’s detail drawing, Sto Canada’s roof/wall diverter flashing detail(December 2015), calls for the step flashing to end in a watertight diverter that sends water to the gutter. It also calls for a 3/8 inch (10 mm) joint around the diverter, sealed. That gap is deliberate. Stucco should stop short of the metal and leave a sealed joint, not bury the flashing.

Other installation guidance makes the same point from the siding side: siding or trim should never extend into the kickout or the gutter, and about 1 inch (25 mm) of clearance between the end of the gutter and the wall allows the wall to be maintained.

The membrane behind the stucco

The building science guidance for stucco walls says the kickout directs water away from the wall surface and the step flashing above is lapped over the kickout. Behind the stucco, the wall membrane then laps over the step flashing. Peter Baker’s water management details, published through ICC, make an important point: step flashing is traditionally installed by the roofer, and problems start when it is not integrated with the wall’s drainage plane. With stucco, the lapping is straightforward to achieve if the roofer and the wall trades plan it together.

What the Canadian code says

For stucco in Part 9 buildings, the national model code section on stucco requires that flashing and caulking conform to the flashing and caulking subsections, and that aluminum flashing be separated from the stucco by an impervious membrane or coating. See the stucco section on BuildCodes.ca for the current 2024 text, effective January 1, 2025. That section doesn’t draw the kickout for you, which is why the manufacturer’s detail matters. For a specific building, the municipality’s building department and the building envelope professional on the project are the final word.

Common failures we look for in Burnaby

A kickout is cheap relative to the wall it protects, so the failures are usually about omission or sloppy lapping, not the part itself. These are the patterns to look for:

• No kickout at all. The step flashing simply stops at the eave and the gutter sits nearby. Missing kickouts often cause concentrated water and serious wall damage.
• A kickout that was folded or sealed badly. Baker warns that improperly folded or sealed kickouts pour a high concentration of water behind the cladding. A bad one can be worse than none.
• Stucco run right down onto the metal. With no sealed joint, the stucco cracks along the edge and feeds water in.
• Wrong lapping order. The wall membrane tucked under the flashing instead of over it sends water behind the diverter.
• A gutter pushed hard against the wall. The gutter end blocks the diverter’s discharge, and water backs up.
• A kickout that is too small. In big storms, gutters can overflow and stream down the walls, so the diverter has to be sized for the flow it meets.

On townhouse blocks, the same missing detail tends to repeat down the row, because the same crew built every unit the same way. If one end wall shows staining, assume the neighbours deserve a look.

Signs you may have a missing or failing kickout

From the ground, with the wall dry, check the lower corner where the roof edge meets the wall:

1. Streaking or dark staining on the stucco directly below the roof end.
2. Hairline cracks or bubbling paint in the same patch.
3. Soft or crumbling stucco near the base of the junction.
4. A gutter that overflows at the wall end during heavy rain, even though it is clear.
5. Moss or algae growth in a vertical stripe down the wall.
6. Interior symptoms: stained drywall, musty smell or a damp corner in the room behind that wall.

None of these proves the kickout is the culprit, since window and deck details can look similar. But they all point to a concentrated water source at that corner. Because stucco can hide damage for years, we would rather check a junction early than open it up late. Our guide to why flashing fails at every transition and our overview of roof flashing in Burnaby show what else tends to fail around the same areas.

Adding a kickout to an existing roof

The fix is not a dab of caulking. The EPA’s retrofit guidance says that where a kickout was never installed, the sidewall at the eave should be carefully inspected for deterioration from bulk water and repaired as needed. The installation involves removing the roofing and enough siding or cladding to expose the existing wall membrane, installing a fully adhered transition membrane, and then installing the new kickout and step flashing integrated with the shingles.

On a stucco wall, that means cutting back the stucco at the junction, not only lifting shingles. The practical sequence looks like this:

1. Inspect the wall edge and sheathing for moisture damage before anything new goes on.
2. Open the roof edge at the junction and remove the lowest shingles and the existing step flashing.
3. Repair or replace damaged sheathing and building paper or membrane.
4. Install the kickout first, fastened to the roof deck and sealed, never fastened into the wall.
5. Re-lap the step flashing and shingles over the kickout, then the membrane over the flashing.
6. Patch the stucco with a sealed 3/8 inch (10 mm) joint around the diverter.
7. Check that the gutter end clears the wall and drains freely, and review where the downspout discharges. Our note on moving downspouts away from the foundation in BC covers that last step.

For related junctions, see our pages on finding missing step flashing and flashing repair steps for BC homeowners. If your gutter and edge metal are also being replaced, drip edge versus gutter apron explains what goes where.

Questions for your roofer before work starts

A good flashing job is easy to describe in words, so a good roofer can walk you through it. These are the points to raise:

• Which piece goes first at the bottom of the wall: the kickout or the step flashing?
• How far will the step flashing lap over the kickout?
• How will the wall membrane lap over the flashing?
• How will the stucco terminate at the diverter, and will there be a sealed joint?
• Is the diverter sized for the roof area draining to it?
• Will the gutter end leave clearance from the wall?
• Who is repairing the stucco and sheathing, and who warrants that work?

For strata corporations, add one more: will every similar junction on the building be documented, so the council can plan the work across the whole complex instead of unit by unit?

Our perspective

Have the junction checked

If you have stucco staining under a roof edge, a gutter that spills at the wall, or a roof you are about to replace, we can inspect the junction and tell you what we find. Our residential roof inspections and repairs cover roof-to-wall flashing, and our asphalt shingle roofing work includes detailing the step flashing and kickouts at walls.

For townhouse complexes and multi-unit buildings, our strata and multifamily roofing services help councils and property managers plan flashing work across a whole roof, so recurring junction problems are fixed once. If water is already getting in, reach out through paragonroofingbc.ca for emergency roof repairs.

FAQ

Is kickout flashing the same as diverter flashing?

Yes. Both names describe the same angled piece at the bottom of a roof-to-wall intersection. InterNACHI uses the terms interchangeably. Its job is to divert runoff into the gutter and away from the cladding.

Does a stucco wall need a kickout if there is already a gutter?

It does where a roof ends against a wall that continues down past the gutter. The gutter alone can overflow in a heavy storm, and overflow can stream down the wall. The kickout steers the water into the gutter before it reaches the wall face.

Can caulking replace a missing kickout?

No. Sealant is not a diverter and does not change where the water goes. A proper kickout is integrated with the step flashing and wall membrane, as the Building America guidance describes. Sealant has a role, such as the sealed joint at the stucco, but only as part of that assembly.

How can I tell if the wall behind my stucco is damaged?

Look for staining, cracking, soft stucco or interior dampness near the roof-to-wall corner. Stucco can hide damage for years, so a visual check from outside may not be enough. A roofer or building envelope professional can open the junction and inspect the sheathing directly.

Sources

• Kickout Flashing, InterNACHI
• Inspecting Step and Kickout Flashing at Roof-Wall Intersections, InterNACHI
• Step and Kick-Out Flashing at Roof-Wall Intersections, Building America Solution Center
• Flashing of Roof-Wall Intersections in Existing Homes, Building America Solution Center
• Kick-out Flashing at Roof-Wall Intersections, Building Science Education Center
• Common Flashing Details, Building Science Corporation
• Water Management Details, ICC
• Roof/Wall Diverter Flashing detail, Sto Canada
• Section 9.28 Stucco, BuildCodes.ca

Recommended

• Burnaby Roof Flashing: What It Is and Why It Matters
• Why Flashing Fails & How to Properly Detail Flashing at Every Transition
• Burnaby Metal Roof Edge Flashing Explained