Constructing a lean to - How to flash edge of roof

I’m a newbie, constructing a “lean to”. Here’s my plan. I’m going to bolt a 2x6 stringer to the side of my garage and run rafters out to the end of my concrete pad to another stringer on 6x6 posts. After I do the framing and install “barn metal” corrugated sheets on the roof I’m not sure how to flash by the building edge. I’m not sure if I should cut the vinyl siding back all the way to the top edge of the stringer so it sits recessed and flat against the building or just trim the step out of the siding so it sits flat. Either way I don’t know how to keep water from blowing up the roof and leaking behind the stringer and down into the building. Does anyone have some recommendations as to what methods of flashing/sealing can be used. Any advice would be appreciated.



You will need to cut out the siding approximately 1 to 1 1/2 inches above the rib of your roofing material not just your stringer. You should be able to buy some roof to wall metal to match the color of your roof. Slide the metal behind your siding and secure the leg that comes onto the roof into the ribs with #9 Grommeted screws. Whoever you bought your panels from should be able to provide closures for the eaves and the headwall.

google installing a ledger. like for a deck. you can find step by step how to install and flash. you should never put anything load bearing over siding like that you have to open it.