Step 3 · Measure Gap and Select Extender
Place a straight edge or level across the drain opening, resting on the finished tile floor. Use a tape measure to measure the distance from the top of the old flange to the bottom of the straight edge. This measurement determines the required thickness of your flange extender. Extender kits come in various sizes (e.g., 1/4", 1/2", 3/4") and some are stackable. Choose the kit that brings the flange height to be flush with or slightly above the finished floor.