I'm planning to build a low-slope roof over a 12x24 patio. I'll be removing the soffit/fascia on the home's exterior wall, cutting off the rafter tails and securing the patio rafters on top of the wall plate w/ rafter ties. In most cases, I'd leave the underside of the patio cover unfinished, except for paint. However, the summers here in S. GA are so hot and humid, I don't want the roof to radiate heat down onto the patio. I know that pre-fab sunrooms use insulated panels for the roof, so I'm wondering if I can't accomplish the same thing by insulating between the rafters and installing a 1/4" plywood ceiling. I'm assuming this is the same way that covered carports are built? Will this work? Should I use fiberglass batt insulation, or styrofoam panels? What precautions do I need to take to make sure I don't have problems in the future? Thanks.