How to Replace a Frameless Glass Shower Door Sweep | DIY A ​frameless shower door sweep​ is a plastic seal attached to the bottom of your glass shower door to prevent the water from leaking out. Without door sweeps, the water tends to run out the glass cabin inside your bathroom, making the rest of the area wet. But with regular use and constant exposure to water splashes and soap scum, this sweep tends to get worn out. You may find your sweep developing tears and cracks and it might eventually need replacing.