Lean-to roof shingle installation

What would be the proper way to install shingles in this application? First pic shows peak of roof that extends past vertical wall of house (far right). Second pic shows close up.

Thanks in advance, fellas. Always appreciate the help, time, knowledge, & experience.

That last course, I would want the shingle to extend to the top with some tar under those last courses to prevent water entry. A person could bend a piece of flashing to crimp around the top drip edge and onto the last shingle before the cap shingle to do the same thing without tar. Also, a little dab of tar on the nail heads would help, too.

Are you talking about the roof over the rear ‘addition’. If so shingle, at least here in Fl would not be allowed on that pitch. It is too low. In any event, Those exposed nails will back out and become leaks.

Even with low slope shingle application methods?

Recommending a flashing over the top of the exposed shingle edges and dabbing tar on top of the exposed nail heads will do the trick.