Originally Posted by
PAG
Agree about the sheet overlap and potential failure of the silicone. I have sheet roofs on both a car port at the front, and an outside terrace area at the rear of the house. The sheets have half inch black foam on the underside (this more for rain noise prevention than any thermal consideration), which also acts as a compression seal on the overlapping areas. The main house is concrete tiled, for which I had PU foam sprayed (50mm) some six years ago. Have been very pleased with it, not only the thermal properties, but it effectively locks the tiles together preventing any slippage and/or leaks.