I recently decided to tackle re-caulking the edge of my tub, which was long overdue. Instead of using a backer rod, I filled a big gap (about a quarter inch) with leftover grout before applying the caulk. After letting it cure for a day, I thought I was all set. However, I've discovered a leak that seems to be coming from around the edges of the tub, soaking the area and dripping into my basement. Initially, I suspected the old tub spout was the issue and replaced it, but the leak persists. I even tested my grout by covering it with plastic wrap, yet the leak continues. My supply pipes seem fine, so I'm thinking the problem might stem from my use of caulk over grout. Before I jump into cutting everything out, I'd love some insights or validation from others who might know what's going on!
3 Answers
It sounds like the grout you used as a backer isn't the best choice since it doesn't flex like caulk does. Over time, the grout could have cracked, allowing water to seep through. While caulk is typically supposed to be watertight, if only a tiny amount of water is leaking through, the issue might be with caulk itself, or it could be coming from somewhere else, like pipes under the tub.
Totally get where you're coming from! Grout is rigid, so it won't help much if there's any shifting. That could definitely lead to cracks, which means your caulk might not hold up effectively. Check if the leak is from above the caulk or if there’s any movement that's letting water sneak in under the tub.
I've had a similar experience where grout between tiles ended up cracking and causing issues. Caulking over grout is a common practice, but if the grout isn't properly supported or if there's movement, it can lead to leaks. It might be worth checking for any movement in your tub or re-evaluating any grouting that might need to be fixed to prevent further issues.