I have a SW corner chimney, four foot per side with a 5’8″ hypotenuse, coming into a metal sheathed, 1:3 gable roof. The block chimney stucco crazed due to poor curing, and particularly where four feet of snow is trapped behind the back of the chimney for most of the winter.
I’m re-doing the roof and seriously considering shingle to lessen the ice formation behind the chimney. Still, no one can figure out how to flash it as a cricket is near impossible given the non-symmetry and double angle of the chimney-roof intersection!
Can this chimney be flashed successfully?
Thanks.
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Suhler, I think I understand what you are describing and I'll tell you what I have done. First, what I am picturing is a chimney 4 x 4 that instead of being "square with the roof" it is coming in "corner first". The chimney is covered with stucco in need of repair. Sorry if I have it wrong. What I am describing is for a shingled roof.
Using string and an angle finder you can measure and fit framing to about anything. If you use string to outline the cricket shape you want then you can get length (point to point) and angle (string to roof surface).
Concerning flashing the chimney, the only method I have confidence in is this: Use a guide to cut a straight 3/4 in groove with a diamond blade (you can get a diamond blade now for a 7 1/4 cir saw now for 12$) in an appropriate place for a "counter flashing". (This would be L shaped with a little 1/2 inch flipper on the short leg of the L.) Sweep all the shingle flashings up on to the chimney (standard procedure) then install the counter flashing in the groove using the flipper and silicone to hold. This can end up being a nice looking job.
If you don't get your flashing INTO the chimney, moisture that penetrates to a certain depth will be behind the flashing, causing leaks and freeze-pushing on flashing.