It looks like you're trying to do the flashing in one piece, and that's
asking for trouble. The correct way to flash at the shingles in the
area you indicated is using step flashing. Step flashing is made up of
short pieces, usually about 5"x7" that are bent in half the long way.
Each piece is slid under a shingle tab going up the roof. You may
have to pull some nails if the shingles are existing. Do a Google and
you'll find plenty of sites with diagrams, pictures and instructions.
The top edge detail (Higher part)
The bottom flashing detail (Lower part)
At top, you may have a continuous metal flashing located under the shingles
But at bottom, no way, you must follow the recommendations given by the 2
previous posters, i.e. step flashing
You can get a good illustration of that system at
See sketch at page 2 of that .pdf document.
So, you would need 2 flashings:
- Continuous one for the top part.
- Step flashing at bottom part
Make sure that the lower step flashing is installed first and then covered
vertically by the continuous top flashing.
If it would be my house, I would do everything with shingles only, no metal,
from an easthetical point of view.
Dig a bit in the Manual of my link or go to
http://www.nrca.net/rp/technical/manual/manual.aspx then open the NRCA
Manual and search in Steep Roofing.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.