For the vast majority of shower doors installed in homes and offices around the world, the water is kept inside the shower via a seal of some type around the edges of the door. In some cases this is an attached seal, but in other cases it is a strip of flexible material that, once adhered to the edges of the door, blocks water from exiting. Over time, this strip may become worn out or detached, requiring maintenance to keep the shower in working order.
A cracked sealer strip is either already leaking water or it will be leaking water in the near future. Once the plastic or rubber material the strip is made out of begins to age, it weathers and cracks, leading to moisture seepage. The only solution is to remove the strip and replace it. You can attempt to cut out the bad section and replace it with a new section with silicone caulk adhered to either end to bond it to the existing strip, but the best solution is to remove the entire strip and replace it with a new one.
A loose strip isn’t the end of the world, provided that the strip is still in good working condition. Visually inspect it to look for cracks or tears. If there are none, re-adhere the strip to the inside of the shower pan or the door with silicone adhesive. Once it dries up, the strip will be as good as new. Don't forget to give it at least 48 hours to dry before using the shower again. Use masking tape if necessary to help hold up the strip while the adhesive dries.
Worn Out Strip
A worn out strip should be replaced for the best results. If the shower door has worn out a section of the strip over time, that section has the potential to leak water out into the main part of the bathroom floor. However, before replacing the strip you should visually inspect the outside of the strip as well as the outside of the shower after use. From here, inspect the seal around the shower door for leakage, as well as leakage to the outside bathroom through the strip under or around the door.
Replacing a seal strip is an easy fix. Most strips are peel-and-stick, which means removal is just a matter of pulling the strip away from the shower panel and then cleaning up the adhesive residue left behind. This may require a straight razor to scrape away excess adhesive, as well as mineral spirits to help loosen any adhesive for removal with a scrub brush. To replace an old seal strip with a new one, ensure that the edge of the shower pan or door where you are putting the strip in place is completely clean, scrubbed with mineral spirits and dry. Peel the adhesive protection from the back of the strip and press it into place. Strips are easily cut with a utility knife. Please note that not all strips are self-adhering. Some require you to use silicone adhesive to mount them in place. For best results when replacing a strip, take the old one in to the home improvement store.