u/TheOneKnownAsMonk

Hello

I'm planning on building a shed in my back yard. I wanted it to be a shed style roof (lean to?) with no gable. The front will be 8 feet tall and the back (20 foot span) will be 6.5 feet to accommodate a slope.

Now the question. Is there a way to calculate the birds mouth dept in order to make the roof flat taking account the 7 foot and 6 foot distance. I'm trying to avoid a hight different on the roof so it's easier to install shingles.

I plan to allow for a 1 foot overhang. Since it's a shed I was going to use 2x6 24 on center. Never built a roof before so I'm not sure if this is even possible.

Thanks in advance. Hopefully the sketch is helpful and I'm asking the correct subreddit.