A roofing system includes at least one row of tiles extending across a surface in a row direction, a first tile of the at least one row of tiles including a rain lock adapted to interlock with a second tile adjacent to and within the same row as the first tile, wherein the rain lock has a lower end, an upper end, and a weakened portion proximate the lower end to allow for removal of a predetermined portion of the rain lock. The second tile of the roofing system includes a corner at the upper end of the rain lock of the first tile, the corner including a notch and a second weakened portion to allow for lengthening of the notch.