Dealing with the summer heat where you live I have a suggestion. When you put on your metal roof, make sure you install a ridge vent and soffit vents. Then apply foil faced foam insulation to the ceiling. The thicker the better. The foil acts as a radiant barrier reflecting the heat back into the cavity created by the roof and foil faced foam insulation the vents evacuate the excessive heat and it will feel like your under a live oak tree. You can apply 5/8” fire rated sheetrock directly over the foam as you finished ceiling.
Even if you decide to put in conventional fiberglass insulation on the ceiling, I would still install a radiant barrier on the roof rafters leaving a space so the roof can ventilate the excessive heat. You’ll be much more comfortable and it will lower you AC bill tremendously, if you so decide,.
Last edited by Phak1; 07/20/2022 2:24 AM.
