Our concrete roof only has a 2.25/12 pitch. I had ruled out ceramic tile because of the low pitch, but found out that it can be installed with foam adhesive over a waterproof membrane. My question now is – how would solar panels be installed? Would the brackets be secured over the tile (through holes drilled into the tiles - with screws that would go through the tiles to the concrete)? Or, should they be screwed to the roof before the tile is installed?