People usually have a wrong idea about how a metal roof might impact condensation on a building. They believe that metal roofs would regularly have the formation of condensation at the backside of the panels between the metal roof panels and the roof deck. Well, that's rarely, if ever the case. Condensation occurs when the dew point has reached as warm moist air comes in contact with a colder surface. That doesn't happen on the backside of the metal roof planes because both are out in conditions that don’t have significant humidity or temperature differential.
When it comes to condensation metal roofing and standard roofing materials are the same. The building’s attic is where some condensation may happen. But the truth is we’ll do anything to make homes and buildings better for energy efficiency. The use of better doors and windows are made, an insulation wrap is applied one the outside. The result is the moisture we generate from cooking, bathing, etc. including venting gas stoves and house plants that are trapped in the building structure. This moisture moves upwards and if not ventilated out, on contact with a cooler surface it condenses, which is usually the bottom side of the wood deck on the surface of the roof starts to cool down in the evening. This occurs no matter what sort of material is used except this can be prevented by simply installing a roof insulation blanket. And it's easily available on the internet if you know to look at the right place.