Metal on old barn roof install question

I am looking to put some metal roofing on a small old hog barn that I keep some junk in. Asphalt shingles are really bad and I have 1 hole to steer clear of when walking on it....

This building has a break or change in roof pitch on one side. What do I need to do about that as far as overlapping the lower (flatter) section with the sheets on the upper (steeper) section? How many inches of overlap is required? I assume a spacer strip needed along the bottom of the upper sheet to allow for that overlap?

This is a low budget project, so no trim around the edges.

There are a bunch of skylights in the roof as hog barns of this vintage in that area tended to have. Those all need to be removed as broken or otherwise in bad shape. But, since there are no windows I am thinking of putting in the clear skylight sections on the metal roof for at least a few of these so its not totally a coal mine in there. Electric power to the building is no longer there so no lights either. Any experience with those holding up? I see the warrantee on them is 10yrs only.

To mention a tractor on this post, I will need to use one to move some rusty iron parked next to the building so I can bring my trailer with the materials and ladders in close.

I built a barn @ 3 years ago and used the clear plastic ridge cap! It is @ 14" wide and the entire length of the building. When you walk in during the daylight hours, you'd think you are outside! Love it.

would depend on how much the pitch changes, my porch roof is flatter the my house roof but probably only by 1" in pitch. I just overlapped by 12 inches and it's been fine.

It depends on how much pitch the upper part has. If it is not enough the water will curl around under the lower edge before it drips off, and may get inside of the lower part.

You should be able to get some flashing that has ribs on it that matches the ribs on
the steel sheets. Just bend it to match the pitch change and install under the upper
sheet and over the lower sheet. Ben

Do yourself a favor and pick up some cheap box store windows and cut em in the walls, I don?t care for fiberglass roof panels. They make a
pitch break flashing to use at your pitch break, and rubber closer strips under the upper steel and above the lower steel. If you buy this steel
roofing from a lumberyard or box store they should know what I?m talking about. Google fabral blue book, you will see a detail of what I?m trying
to explain, this method is an industry standard, we?ve installed a bunch!

Depending on the profile of metal you are going to use, polycarbonate clear or opaque panels are available for most profiles. In my wood shop, I have full roof length clear poly 'c' panels (3) and crylon opaque on the inside. There is an 8" air space between the 2 (2x8 rafters) and it seems to work well. Lots of light and no need for shades !. HTH P.S. I have to admit that I planned for the metal roof and skilites, but $$$ being what it is/was at the time, I spaced the rafters for the skilites, sheathed the whole shebang and used rolled roofing for a few years.

The make a flashing for the profile change. As long as the shingles are laying flat, you can put down a special fabric and put the steel on them.

My flashing was pre-bent and has no ribs and doesn't leak. They make foam strips that follow the rib contour to keep water and wind from backing up under the flashing.

Thanks for all the tips!