Got a little issue with my caulk around the tub:
Notice the cracking–had this happen with the original caulking (TEC brand, unsanded silconized acrylic latex caulk) so I redid it with another brand (Safecoat), making sure to be super-anal with the prep.
After letting it cure for 2 full days, began using the shower and tub and began to see cracking pretty much right away. Now most of the application has a nice wide crack running down the middle, as in the picture.
Tub is installed solidly, with flange running up behind durock onto which is mounted the tile with thinset.
I don’t believe there’s any movement happening, although I could be wrong. Seems more like a shrinkage issue with the caulk.
Talked to my tile guy, a seasoned pro who did all the tilework, he says he rarely uses unsanded caulk anymore. So I picked up a tube of Mapei Keracaulk S, the sanded stuff. But before I tear into this for the third time, I just wanted to check with y’all–do you see this kind of thing with tubs? What’s usually the cause? Do you think a sanded caulk carefully applied will prevent this problem?
Replies
Never had the problem, and I doubt that sanded caulk will be any better. There is probably some motion -- could be the walls moving up or the tub moving down, due to temp/humidity changes, or just weight.
In addition, you should be using a bathtub caulk -- essentially pure silicone, or something more exotic. "Siliconized latex" is generally a standard building caulk, not with the flexibility and moisture resistance needed for bathtubs. But judging from the size of the crack even regular bathtub caulk may fail.
One trick that some claim will work is to fill the tub with water while caulking and until the caulk sets. The additional weight in the tub opens the crack slightly, so the caulk will be under compression most of the time. I've never found this necessary, though.
We find that silicone caulk works best to avoid cracking at the tile/tub joint. You have to disimilar surfaces in terms of material so movement will be different due to tempature etc.
Also we find that all tubs, except the best cast iron units, move quite a bit so we bed them all in mortar. Hanging from the studs and a rail in the back there is still a lot of flex for modern tubs. Filling the tub before caulking does help on a problem installation but I would still use silicone since you know there is a problem. DanT
I use Polyseamseal for that application and have never had any problem with it.
Try using Geocel 2300.
Like the others said there's two problems:
1) the weight of the tub filled with water and the occupant
2) not using pure silicone caulk
Correct those two things and you'll have a lasting caulk job. BTW when caulking tubs, I normally tape on either side of the joint so that the bead looks uniform.Jason Pharez Construction
Framing Contractor
Thanks for comments everybody. Guess I'll redo the caulk once again, but fill the tub first and use a pure silicone caulk.
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Make sure it's a "bathroom" caulk. There are some silicone caulks that aren't labeled "bathroom" and which lack the mildew resistance of "bathroom" caulk.Also, you generally want a "non-paintable" caulk. "Paintable" silicone has a very dull texture, collects dirt, and yellows rapidly.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
For those who want to prevent or minimize the crack, stiffen the floor under the tub, fill the tub when caulking and nail a 2 X 4 on the wall to support the rim.
None of the Do-it-yourself books show the problems WITH solutions. We learn from our mistakes. With every posted problem, there was something that should have be done during construction, but it may come too late for the poster.
I actually didn't install the tub myself--my contractor did. But I probably should've done it myself, knowing what I know now!At this point I don't think it's worth tearing the whole thing out. I'll try filling it with water and caulking with pure silicone--hopefully that will suffice.
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Yeah, you should be OK by filling 1/2 full and caulking with silicone. I didn't fill mine up first but I did use masking tape all around to make it look pretty...that was 2 1/2 years ago and it's still holding up fine w/ no mildew or cracking...BTW I used GE Silicone II "Kitchen & Bath" I think it was called.
If it falls apart again in a year, the worst is you will spend another half day peeling out old caulk LOL!Jason Pharez Construction
Framing Contractor