we just moved into a house 6 months ago and this is the second time I have caulked it around the bottom rim where the fiberglass or plastic floor (not sure) comes in contact with the tile walls and glass. the first time I am pretty sure I didnt make the bead big enough because it began cracking and mold began to appear.

I cleaned it throughly with bleach and let it dry, I went over it again and put a very thick bead of caulk around the bottom rim and let it sit for 2 full days. Ended up being around 54 hours but on one side it has begun to split in the middle of the bead. for about 1.5 feet. my assumption is when you get in the shower that side will sink slightly and the bead just cant hold up. Can I just fill in the small crack again with caulking and it be ok or is this a bad problem I need to worry more about?

its driving me crazy!!

 

What type of caulk did you use?

A silicon such as GE Silicone II with BioSeal, will be more flexible and resist mildew and mold.
Scrap all the old caulk out and make sure no water is weeping down.Then re-caulk it. Put a little denatured alcohol in a spray bottle and spray the caulk bead if you need to tool it or run your finger over it. The alcohol will prevent the caulk from sticking to your fingers.

 

Its called PolySeamSeal in a white and blue tube. Says Kitchen and Tub Caulk and Sealant all in one......resists mold, etc.

 

Your fiberglass pan should have been set in a bed of mortar to reinforce it, so that it doesnt flex or move when you step into it. If its moving, no caulk will hold up for very long. Caulk will absorb a small amount of movement, however if the pan is not set properly and there is too much movement, the caulk will fail.

 

If that's the product I think it is you might get slightly better flex from silicone but it's hard to say how much improvement it will be.The product you used is a good product.

As stated if there is enough flex you may have to regularly replace the caulk and if that's the case using silicone may be a problem as it is far more difficult to remove and redo.

 

try-putting a couple of bags of play sand (still in the bag) for weight, before installing the caulk.