My home is 21 years old and we have been fighting the caulking around our tub for the last 5! The bathroom is upstairs and has a window in it for ventilation. I recaulked it and the caulking almost melted within a couple of weeks. I thought perhaps I didn't let it dry enough before using the shower so pulled the remainder out and recaulked again. I waited a week before using the shower but the same thing happened. I then caulked and put "L" shaped plastic around the tub. It didn't stick either and again the caulking melted. I thought maybe there was water behind the tiles so pulled the caulking off and the plastic and didn't use the shower for two weeks and once again caulked. We are still fighting!! I thought maybe putting in a tub surround would get rid of the difficulty but then thought it might just be covering a "real" problem and could make it worse in a few years. We also have a problem with mold in that bathroom. I bleach the walls and ceilings but it continues to come back. I repainted in a special paint to deter mold but we still have the problem. We have other showers in the house and have never had such problems.However, this is the most used shower with my husband and 4 boys showering daily. PLEASE HELP!!! ps...I am using caulking specifically for tubs. Thanks.
Re: Tub Calking
one thing you can try is removing the soap scum from the tub and tile. Rubbing alcohol works well for this. Let it dry. Then use 100% silicone calking. Silicone is much harder to use but will do the trick. Be patient while working the silicone. It takes forever to get it smooth but it will smooth out and seal.. Let it stand for 24 hrs. Dont clean it for 5 days to let the silicone fully cure.
Re: Tub Calking
More than likely there is residual moisture behind the surround that is weeping out behind the newly laid caulk. The only way around it is to lay paper towels or tissue along the tub edge where it meets the surround, and replace it as often as necessary as it wicks out the moisture. This will be a long and tedious process, but will be about the only way to get the majority of the moisture out before recaulking with latex caulk and having any hope that it will stay intact.
tgb's suggestion of using a silicone caulk will be the expedient method. There is a trick to using silicone that works exceptionally well, and that is to put rubbing alcohol in a clean misting bottle, such as that used for pump hair spray. Carefully lay in a small bead of silicone, just enough to close the gap, then lightly mist the surface of the silicone and also the tip of your finger with the alcohol. Now, wipe the bead of caulk in short strokes, 3" to 6" at a time, cleaning your finger on a paper towel and rewetting it with alcohol between strokes. Silicone won't stick to the alcohol, making the bead and your hands much cleaner for the task. Once you've made the short strokes from end to end, clean and rewet your finger one last time and make a single stroke from end to end to have a perfectly smooth joint.
This same installation method works with latex caulks as well, just omit the use of alcohol, since latex is water clean up.