I've got a fiberglass shower with a 3-part design: a base and two upper sections. I've replaced the caulk twice due to mold issues, but it keeps cracking, especially under the overhang where the top meets the bottom. The second attempt looked better than the first, but I'm still seeing cracks after just a couple of weeks. The gap between the top and bottom is actually quite deep—deeper than the caulk can fill. Could this depth be a reason for the cracking? Do I need to find a better way to fill this space? It seems like when it was installed, they applied a solid layer of caulk before placing the upper sections, which made it hard to replace initially. Any advice would be greatly appreciated!
3 Answers
Hey! It sounds like you might be using the wrong type of caulk. Make sure you're using a high-quality 100% silicone caulk. If the gap is really deep, you might also want to consider using a backer rod to give the caulk something to adhere to. A picture would definitely help, but these steps could improve the situation a lot!
Cracking caulk typically means there's a lot of movement between surfaces. Have you noticed any shifting when you stand in the shower versus when you're not? That could be the root of the problem. You might also want to try filling the tub with water before recaulking. This can help alleviate some of that movement when doing the job.
Switch to silicone if you aren't using it already. Try filling the tub with water, apply silicone around the edges, and let it cure for at least 24 hours before draining it. It's also really important to remove all the old caulk to ensure a clean seal!
Unfortunately, I can't share pics here. Just to clarify, my shower is in three parts: the base is a single piece that goes up 2-3 feet, and the upper parts meet in the center with an overhang. A friend suggested that there shouldn't even be caulk in that area, which has me second-guessing everything.