Gutter System Installation Standards Product Specification

5. Begin by driving a nail into the fascia at one end of the gutter-run wall a half-inch below the top of the fascia. Stretch a mason's line from the nail. To properly align the slope (using a line level on the mason's line) drop one end of the line a quarter-inch for every 10 feet of fascia length, then mark that point with a pencil.