Are Kickout Flashings Necessary?
I recently had a roofer tell a client of mine that kickout flashings were "overkill." It was the roofer's opinion that the roof step flashing and the ice and water shield that he installed under the roof shingles would protect the roof. Well .... he was partially correct. These elements do help to protect the roof from moisture damage. But that is not the area the kickout flashing is designed to protect.
The kickout flashing is designed to divert water that runs down off of the roof into the gutter and away from the wall. If water gets behind the wall at this location, the area of moisture damage is typically at or below the roofline/gutter. The damaged area can spread down the wall to the wall base depending on the amount of moisture penetration and the time period the damage is allowed to occur.
So while the roofer was correct that some added elements work together to protect the roof, the simple addition of a kickout flashing will also help to protect the area below the roofline. On stucco homes, this is not something that a roofing contractor is prepared to handle, nor do they want the responsibility, which is most likely the reason for their opinion. It requires removing a portion of the stucco wall to install the kickout flashing directly to the wood sheathing, overlapping all of the weather resistant barriers and other flashings, and then installing new stucco to match as best as possible to the existing stucco. A professional stucco repair contractor is best equipped to handle this type of repair.
Installing a simple kickout flashing may cost a few hundred dollars but could save homeowners thousands of dollars in stucco removal and damage repairs in the future. That is definitely not considered overkill in my book. I call it "being a responsible homeowner."