Twenty years ago, few people had ever heard the term “kickout flashing,” but things have changed. Old homes leaked so much air that walls always dried out. Today’s homes are much tighter and walls hold moisture. Walls, siding and oriented strand board (OSB) will rot if water enters the wall. Kickout flashing has become essential.
Here’s a great example
That same energy equation applies in our homes. When a valve opens, pressure in the system pushes water through the fixture. Close the fixture and the water stops; the energy of the moving water is then absorbed by the piping and the remaining water. An abrupt halt can trigger a loud “hammer” and, over the long term, it can even damage piping.
In one case I investigated, the routine inspection of a window interior didn’t hint at any damage (Photo 1). A home inspector would never suspect an issue and, in fact, there was no visible issue to report. But the owner showed me ground-up wood on the windowsill. She explained that when it rained, water dripped from the upper trim. The “ground-up wood” looked like carpenter ant frass (droppings).
We lifted the upper window casing (trim) and discovered rotted wood and dark frass from carpenter ants (Photo 2). This major issue would be invisible during a normal home inspection.
What else was going on?
On the outside, the wood siding and trim of this 20-year-old home seemed to be in good condition. Three—yes, three—contractors had examined the leaky window. They applied liquid flashing (caulk) at the step flashing and sealed the cap flashing at the window.
Whenever I see window leaks, I always suspect missing flashing or improper layering of the weather-resistant barrier under the siding. Sure enough, when I looked at this window from the outside, the problem was obvious: The gutter terminated at a sidewall with no kickout flashing (Photo 3).
A preventable problem
When properly installed, kickout flashing should channel water down the outside wall assembly and into the gutter (Illustration R016). Compounding this particular water problem was a gable roof and a downspout directing rainwater to the roof above the end of the gutter.
The fresh caulk that the contractors applied between the siding and the top of the window cap flashing may have worsened the problem. Horizontal flashing or cap flashing should never be caulked. Because all types of siding leak, the cap flashing should be installed underneath the weather-resistant barrier to capture water and route it out of the wall assembly over the window.
The solution here? Remove the siding above and around the window. Check the weather-resistant barrier and install kickout flashing. Replace rotted materials. And finally, route the upper roof drainage away from the area.
You must catch this obvious defect
Inspecting only the window and the wall from the inside would never reveal the source of the problem, so you must always identify the lack of kickout flashing. A contractor smart enough to notice the missing flashing would say, “The home inspector should have seen this defect.” Don’t let them say that about you.
To learn more, attend Tom’s technical presentations at educational sessions for ASHI chapters. Tom will present “Basement Inspections, Reporting and Identification of Defects” at ASHI InspectionWorld® 2020 in New Orleans.
Tom can also provide his knowledge for your educational event; contact him at Tom@HTOYH.com.
Tom Feiza has been a professional home inspector since 1992 and has a degree in engineering. Through HowToOperateYourHome.com, he provides high-quality marketing materials that help professional home inspectors educate their customers. Copyright © 2019 by Tom Feiza, Mr. Fix-It, Inc. Reproduced with permission.