Tin roof lean to plans

Lean to roofs are the easiest ones to frame and finish. Why not weld bolts to the container and bolt your wood framework down to it. That way no drilling into the container and a much stronger roof to boot since it will be bolted down.

How wide?

you can get by with 24 inch centers since you have to lay 1x's over the rafters to secure the tin to. You run the 2x6x12 the width and on top of that you put down 1x4 or 6's the length of the container to screw the tin roof to. If you were putting plywood over the rafters and a seal tab roof, I'd recommend going on 16in. centers. But for light tin, it is not necessary.

I like to do this about every 2 ft. up the width of the roof and I like to use 1x6 to do this so if you need to walk on the roof at a later date you have a nice chunk of lumber under your feet to not kink the roofing.

I would probably rather shorten my framing than go with longer tin. Have a hookup on 12' tin

1/4” per foot will work fine for a lean to.

Pro tip: check square on your tin every 4th sheet.

4x4 or 6x6 posts?

Here is what I built last year:
i used 2x6 for the rafters, double 2x8 for the beams, 6x6 for the post. (4x4's probably would do the job, but look way too small/ugly)

it wasn't too bad. I pulled up the bottom part of a row of shingles( the tarred down part) and shoved the flashing up until it hit nails. then I put tar on each side of the flashing to re-glue the shingles down.

If I had a good hook up on 12 ft tin, I think I would put the roof over the container as well.
Would certainly help keep it cooler inside, without the Sun beating down on the top.