Kickout flashing might be one of the most important details to get right when it comes to preventing major water damage to a building. Kickout flashing is a simple little piece of metal that directs water out and away from a building when a roof surface ends at the wall. The illustration below, used with permission from the fine folks at CodeCheck, shows how this works.
Here's an example of kickout flashing not installed, along with major water damage below the area where the kickout flashing was missing.
The rotted siding shown above is just the beginning; the real damage will be inside the wall. Here's another photo showing some more obvious damage.
Kickout flashing has been a requirement in Minnesota since 2007, when the 2006 IRC was adopted. The 2006 IRC made no reference to kickout flashing, but the Minnesota State Building Code amended section R703.8, and this text was added on:
[Approved corrosion resistant flashing shall be installed at all of the following locations:]
9. Where the lower portion of a sloped roof stops within the plane of an intersecting wall cladding in such a manner as to divert or kick out water away from the assembly.
This is still the building code that is in force in Minnesota today. My only beef with this language is that it's not very specific, making cheesy installations like the type shown below 'legal'. Arguably.
I guess it's better than nothing, but come on! That's just silly. The only reason I find goofy installations like this is because of ignorance; it's quite simple to make a perfectly effective piece of kickout flashing with a standard piece of step flashing. If everyone knew how to do it, it would always be done right. Here's a short how-to video that I made, which shows how to easily bend up a piece of step flashing to create a kickout.
