# Under flashing and counter flashing cedar roof to wall intersection?



## drewterryvt (4 mo ago)

I am in the process of replacing the small section of green, peeling cedar roof shingles you see in the picture below. I am using #1 blue label certigrade perfection western red cedar shingles, and plan to modify the current installation of 3 course/5.5" exposure to be 4 courses with 4" exposure. 

I plan to install copper counter flashing over the top course of shingles to cover the face nailing of the top course, and the entire deck will be covered with ice and water shield at least 2" up the wall and cedar breather. I have copper step flashing for the sidewall angled sections, and plan to install copper counter flashing over the extreme left and right shingles of the first course.

My question is do I need to install under flashing between the 2nd and 3rd course if I am also counter flashing?

The diagrams I have for cedar shingles all specify flashing under the top 2 courses and at least 3" up the wall. Do I need this flashing on such a small roof, given the counter flashing and the deck flashing membrane? I had planned to do painted galvanized under flashing down 7" on the roof and up 3" on the sidewall, but is that over kill?

I have included a diagram of the under flashing and counter flashing for concave roof juncture in figure 10 below. They show one or the other, not both on the same diagram. Is that because you only need one or the other?

Any feedback is very much appreciated, thank you!


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## roofermann (Jul 7, 2012)

Will the wall leg of your new flashing be going under something, like that frieze board?


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## drewterryvt (4 mo ago)

roofermann said:


> Will the wall leg of your new flashing be going under something, like that frieze board?


I plan to bring the wall leg up the wall 2-3" and tuck under the green molding and the lower edges of the cedar wall shingles. The more I think about it, it seems like flashing under the top two courses AND counter flashing over the top course seems like overkill, but that's okay if it means it will last longer. I am concerned that flashing under the two top courses will prevent much of the roof from drying out.


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