I've been scouring the internet to figure out how one would do this transition from a low slope (1:12) section and a 4:12 pitch section that has cedar shake that also wraps around a corner of a vertical wall.
Currently there are asphalt shingles - likely installed 10+ years ago by previous owners - and they are getting very close to failure. I'm considering replacing the asphalt shingles on the low slope portion with EPDM and will extend the sheet below the upper cedar shake shingles and valleys ~1-2 ft and running the membrane up the vertical wall all with a single piece (~15 ft x 4 ft).
The biggest issue though is the corner of the vertical wall where everything kinda converges from the low pitch section and the higher pitch cedar shakes.
I've attached photos of the entire flow path with red arrows showing the low pitch portion and green arrows showing the higher pitch. It also appears the low pitch slopes away from the vertical wall and forms a bit of a valley where all the shingles are worn out from water flow.
I was thinking I would remove the cedar shake around the corner, lay down some new metal flashing around the corner with the metal flashing landing on top of the next course of cedar shake below the corner, and then use EPDM adhesive to bond the membrane to the flashing. The Carlisle EPDM details shows that their SecurTape can be used on metal as well with adhesive and tape together. I can't really find any detail drawings that show this sort of detail.
Another concern is that I live in a climate with lots of snow and temperatures that can drop to -40C for a week at a time in winter and I'm concerned about ice damming at this corner as this section is above my attic (not heated but poorly ventilated) until it swings around the corner and then its over the edge of the attic framing and will be frozen solid.
Any help would be much appreciated regarding the transition detail around this corner.
Currently there are asphalt shingles - likely installed 10+ years ago by previous owners - and they are getting very close to failure. I'm considering replacing the asphalt shingles on the low slope portion with EPDM and will extend the sheet below the upper cedar shake shingles and valleys ~1-2 ft and running the membrane up the vertical wall all with a single piece (~15 ft x 4 ft).
The biggest issue though is the corner of the vertical wall where everything kinda converges from the low pitch section and the higher pitch cedar shakes.
I've attached photos of the entire flow path with red arrows showing the low pitch portion and green arrows showing the higher pitch. It also appears the low pitch slopes away from the vertical wall and forms a bit of a valley where all the shingles are worn out from water flow.
I was thinking I would remove the cedar shake around the corner, lay down some new metal flashing around the corner with the metal flashing landing on top of the next course of cedar shake below the corner, and then use EPDM adhesive to bond the membrane to the flashing. The Carlisle EPDM details shows that their SecurTape can be used on metal as well with adhesive and tape together. I can't really find any detail drawings that show this sort of detail.
Another concern is that I live in a climate with lots of snow and temperatures that can drop to -40C for a week at a time in winter and I'm concerned about ice damming at this corner as this section is above my attic (not heated but poorly ventilated) until it swings around the corner and then its over the edge of the attic framing and will be frozen solid.
Any help would be much appreciated regarding the transition detail around this corner.
