Step 8 · Secure Flanges to Studs
With the pan level and the drain connected, secure the vertical mounting flanges to the wall studs. Drill pilot holes through the pre-marked spots on the flange directly into the center of each wall stud. Fasten the flange using 1-1/4 inch galvanized roofing nails or pan-head screws with large washers. The large head of the nail or washer prevents it from pulling through the plastic flange. Install one fastener per stud. Do not overtighten, as this can stress and crack the flange.