Abstract: A frame apparatus for a fenestration unit comprising an elongated frame member including a first side and a second side, wherein the largest distance between the first side and the second side defines a width of about 1.25 inches, the elongated frame member also includes a first end and a second end, wherein the largest distance between the first end and the second end defines a length of at least 5.625 inches, wherein the first side includes an exterior notch at least 0.25 inches from the first end, wherein the exterior notch is at least 0.1 inches wide and at least 0.2 inches deep and the second side includes a backcut located at least 2.0 inches from the second end, wherein the backcut measures at least 0.25 inches deep and at least 0.1 inches wide and wherein the elongated frame member includes a ridge.