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Existing asphalt roof meets new wall (Zone 6)

user-1142226794 | Posted in General Questions on


 I have a renovated second floor wall running up past the existing 15/12 roof line (both terminating at the same peak) *see pics. I am trying to keep the existing asphalt shingles and wondering about how-to flash the wall-roof section. I found some really great stuff from Mike Guertin in his article “Kickout Flashing: Often Overlooked and Under Appreciated”

I am trying to integrate the steps he outlines while keeping the existing roof intact if possible. My renovated wall is taped plywood sheathing, 2″ of poly-iso, Mento 1000, strapping, 8″ aluminum siding. My plan is peal and stick flashing plywood sheathing to roof sheathing, then put in the 2″ rigid, then Ice and Water that intersect (The problem being that I am almost on top of the asphalt at that point, should I cut the shingles back further?) Then step flashing with a kick out away from the wall, using Geocel where I can to protect the wall. After that run the Mento 1000, strapping and siding. 

 Please let me know if you have any ideas or resources. This area is ‘protected’ by about 16″ overhang.

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  1. mr_reference_Hugh | | #1

    I don't do roofing but this is what was done at my place. The images attached are taken from this Home Depot page. It is pretty simple and straightforward.

    1. user-1142226794 | | #3

      Okay, great thanks. I was worried b/c I saw so many more steps in other posts and on prints from other houses. Putting Ice and Water 16" on either side etc.. I've got the step flashing.

  2. Expert Member


    You need step flashing installed as shown on the drawing Hugh posted, and at the bottom a kick out flashing.

    1. user-1142226794 | | #4

      Okay, so no peal and stick is ok in this situation. Just put in what I can and flash all the way up the existing roof. I'll give that a try, thanks for the reply.

      1. Expert Member
        MALCOLM TAYLOR | | #5

        On new installations a layer of peel & stick would go on before the underlayment, but trying to retrofit one now will probably result in damaged shingles. Done properly the step-flashing will work fine.

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