When properly installing drywall or like-surfaces above a shower base or bathtub, the 1/4” gap between the top of the tile flange and finished wall should be carefully sealed with a high grade silicone sealant. Unfortunately, drywall installers fail to make that seal in most installations. Mustee’s patent-pending GapSeal-Pro™ tile flange seal solves that problem by sealing the gap and “extending” the tile flange to create a water barrier behind drywall or like-surfaces.