Truss Roof Over Factory Metal Roof

[Bruce71913]

I live in Arkansas, cold winters, hot humid summers. I want to put a metal roof on my 14' x 51' home using a truss system. I currently have a slightly arched metal roof that has a small leak at one one the seams that I plugged with solar-seal (whatever it's called). I am tired of resealing the roof every couple years. Enough background.

I want to install a metal roof using a truss system that doesn't touch the old roof (except around the perimeter), which is easy enough to design. So my question is do I need to worry about sweat (in summer) or ice (in winter) and mold/mildew forming between them?

I thought maybe applying a coat of solar cool & while its wet covering it with 1" styrofoam to assist in insulating

Thought anyone?

[Bruce71913]

P.S. I forgot to mention that I am trying to avoid sheeting the roof with plywood. This is what prompts my sweat question.