Many people assume that metal flat roofs do not require ventilation because they are sturdy and reflective. However, that is far from the truth. Like any other roofing system, metal roofs need adequate airflow to prevent condensation and heat accumulation. During hot weather, a poorly ventilated metal roof can trap heat, raising indoor temperatures and forcing your HVAC system to work... https://ahsiroofingandwindows.com/roof-ventilation/