What is a kickout flashing and why is it critical on stucco homes in Ottawa?

Kickout flashing is a specialized piece of metal flashing that directs water away from the intersection where a roof meets a sidewall, and it's absolutely critical for preventing water damage behind stucco in Ottawa's harsh climate. Without proper kickout flashing, water running down your roof can get trapped behind the stucco system, leading to rot, mold, and expensive structural repairs.

Understanding Kickout Flashing Function

Kickout flashing works by capturing water that flows down a roof slope and "kicking" it out and away from the building rather than allowing it to run down the wall surface. At roof-to-wall intersections, standard step flashing alone isn't enough because water can still flow behind the wall cladding. The kickout flashing piece extends beyond the wall plane and includes a hemmed edge that forces water to drip away from the building. This is especially important with stucco because stucco systems are designed to shed water, not handle concentrated flows from roof runoff.

In Ottawa's climate, this detail becomes even more critical because of our intense freeze-thaw cycles and ice dam formation. When water gets trapped behind stucco and freezes, it expands and can cause the stucco to crack, spall, or delaminate entirely. I've seen Ottawa homes where missing kickout flashing led to complete stucco failure and thousands of dollars in repairs within just 3-5 years of installation.

Proper kickout flashing installation costs between $150 and $300 per location when done during initial construction or roofing work. However, retrofitting kickout flashing on existing homes can cost $400 to $800 per location because it often requires removing sections of stucco, siding, or roofing materials. The investment is minimal compared to the potential damage - stucco repairs from water infiltration typically run $3,000 to $8,000 per affected wall section in Ottawa.

The Ontario Building Code requires proper flashing at all roof-to-wall intersections, and kickout flashing is considered best practice even where not explicitly mandated. Many Ottawa contractors now install kickout flashing as standard practice on all stucco homes because they've seen the damage that occurs without it. EIFS systems are particularly vulnerable because the foam insulation can retain water and create hidden damage that isn't visible until it's extensive.

Installation timing is crucial in Ottawa's climate - kickout flashing must be installed during dry conditions and properly sealed before winter weather arrives. The flashing needs to integrate with the water-resistive barrier behind the stucco and should extend at least 4 inches beyond the wall surface. Common materials include aluminum, galvanized steel, or copper, with copper lasting longest in our corrosive winter salt environment.

If you're planning stucco work or roof replacement, ensure your contractor includes proper kickout flashing at all roof-to-wall intersections. For existing homes showing signs of water staining or stucco damage near roof lines, have a professional assess whether missing or failed kickout flashing is the culprit. You can browse experienced contractors familiar with proper flashing details through the Ottawa Construction Network directory at justynrookcontracting.com.