Inside roof you have 1" square tubing around the inside perimeter of the roof vent/AC unit. Watch out for the fiberglass insulation between the interior panels and actual roof. The roof is aluminum skin. Check for galvanic "rot" due to the reaction of dissimilar metals in roof. look for areas of white crust, rust on steel frame members, or wet insulation these will give an indication of where your water infiltration is. I used Tropicool on my roof after fixing my water infiltration. Sealed anything that passed through roof with EternaBond (plumbing vents, roof vents, etc.) before I rolled on Tropi-Cool. Have not had a drop of water come inside since.