View Full Version : tub caulking won't dry. Slow leak behind wall?

07-16-2007, 08:34 PM
I replaced the tiles and wallboard in my shower/tub.

I don't think I damaged the existing pipes, but a few months later, all the caulking has turned to soup only in the one back corner at the end where the fixtures are (in the corner, not directly under the taps).

I replaced the bead once, but it still won't dry on the inside. The outside forms a skin, but it all washes away from behind when it gets saturated.

I don't hear any leaks, and I can't really feel any moisture when I pull the flanges off and squeeze my finger in behind the wall as far as it can go.
Also, when you walk down the stairs and look up, you're looking at the floor beneath the tub, and there's no visible water damage.

Anybody run into something like that?
I didn't want to start breaking tiles up and cutting holes in the durock to explore for a leak if there's a common explanation.

The gap between tile and tub is just under 1/4". Pretty big.... maybe its taking way too much time to dry out before we start using the shower? I've tried to let it dry out for at least 12 hours and then cover it with a towel when we do for about 3 days.

Thanks for the thoughts guys!

07-16-2007, 09:44 PM
If there really is no leak, then try using 100% silicone and letting it dry for 24 hours before using the shower.

07-17-2007, 06:29 AM
Read the fine print on the caulk...some of them like 7-days to cure.

Take a level and check the tub end-to-end and side-to-side to see if it is level. You may find that it it tilted towards that corner.

07-17-2007, 03:53 PM
Could be water leaking through the grout and getting behind the tiling - that can stay wet for a while...

07-17-2007, 04:33 PM
Humorous thought, though not likely....sure you didn't use clear caulking?
It goes on white...dries clear.

07-17-2007, 05:29 PM
product you used. Tell us please. Thank you .


07-17-2007, 05:37 PM
Thanks guys.

GrumpyPlumber, no, it's white tub & tile adhesive caulk.

07-17-2007, 05:47 PM
wrong product. The page linked to doesn't say much. Doesn't say what it is made of. Duh.

I saw that it is paintable, and it can be "water clean up" upped. That is terrible. Anything that brags that you can wipe a wet rag over it, isn't able to brag about being far far more waterproof. From what I know, any caulk that is paintable is NOT 100% silicone, and that pure silicone is what you need around a tub. That is what I think I know, from reading here and elsewhere, from building bathrooms, from seeing what other people do, etc.

You have a shower in your tub space. That makes the inevitable, a fast occurring reality.


07-17-2007, 06:23 PM
Thanks Geniescience.
The closest thing to "silicone" on the label is crystiline slica. You're probably right.

Since I've got the wet caulk all pulled out, I ran the water through the shower head and the spout for about 5 mins each.
Nothing is seeping out from behind the backerboard and into sight.

I'm thinking it might be the spout.
Sorry, I can't find an exact picture. Here's the closest resemblance:
Mine is rectangular and pretty cheap looking.

I can pull that spout right off without a fight.
It leaves behind a white plastic sleeve that grips the pipe. Sorry, not sure what it's called.
Maybe that's it? Could backpressure be seeping back in through the hole in the wall and down to the caulk?

07-17-2007, 07:27 PM
Thats just standard latex bath caulking...my hands are up...a mystery.
Did you clean the surface prior to caulking?
I'm wondering if there's maybe some oil based substance there....shot in the dark.
Maybe...just maybe a hot blowdryer might help it cure.

07-18-2007, 09:32 AM
Since I've got the wet caulk all pulled out, I ran the water through the shower head and the spout for about 5 mins each.
Nothing is seeping out from behind the backerboard and into sight.
You eliminated a plumbing leak with that test. Good. But you need to find out if water is getting past the tiles and grout.

If you have a hand-held shower, turn on the shower and spray the tiles up and down and all around the problem area.Then quickly dry off the area where the caulk won't dry. See if water is seeping back into that area after it has been dried. If it is, you need to fix and seal the grout.

If you don't have a hand-held shower, you'll need to spray the area using a garden hose or use some other method.

07-19-2007, 01:08 AM
using the wrong product meant failure. The wrong product will fail. It will act up and die. It will do things that you don't want it to do. It may make you think there is another problem like for example a leak coming from behind. Now it's got you worried. For no reason? With good reason? Now you don't know, and you are going to spend sleepless nghts worrying.

The product failed because shower water was wetting it. The product is not designed to be wet. In the long run, when regulations become perfect, the product will not be able to be sold with its current description. The product describes itself in misleading terms. It fooled you into using it. Now you think you may have a leak. It failed because of the shower. Not because there is any other water coming from behind. Unless I'm wrong.

Using the right product, you wouldn't be wondering if there was a leak. The silicone would have stayed stuck.


07-19-2007, 03:13 PM
This product should work. I've used it alot and only had problems when it got wet before fully cured. The area to be caulked has to be DRY to begin with, I like for the area to not be used for 24 hours before hand. The manufacturer recommends 36 hr. to cure.