cracking caulk around the tub

If anyone has had experience with this problem I would appreciate some advice. The freshly caulked lines on a new bath tub and new tile surround redo has cracked for the second time. I bought the tile and grout caulk, acrylic formula, silconized, moisture and mildew resistant from the tile store. (Interceramic) It matches the grout color.

One rep at the store says he never uses it for around the tub, after I complained the first time. He said I should use clear. The other guy says he uses it regularly. My tub is white and the grout is oyster gray.

Any ideas as to why this would crack before it even dries? I'm talking within the hour on the second try. I used the DAP caulk helper to make some great lines this time thinking I may have not gotten the caulk in to the space far enough the first time.

Is this the wrong caulk?

Hi Kari,

Very unusual for caulk to crack so soon. Heck, it's still soft after one hour. Makes little sense to me.

Is this a regular steel tub? Ceramic tiles on the walls? How wide is the gap? Is the bead of caulk a little wider than the crack? It's either very old bad caulk or your walls and/or tub are moving too much.

The caulk wouldn't crack if there wasn't movement. A little can be expected though, hence why caulk is recommended.

Remove it all. Wipe the area with denatured alcohol. Fill tub with water, at least half full. Apply caulk. Drain water the next day.

Is that how you did it?

Jaz

Thank you for your reply Jaz!
My tub is Kohler cast iron. The tiles are 12 inch ceramic and they come down over the tub lip. We left a gap of 1/8 of an inch or less.

I used the pro caulk tool for 45 degrees, 5 mm, convex lines. Maybe that is too much caulk?

But the movement issue might be the problem, since it did crack the first time when I did it free hand.
And we have heard the tub move a bit, creaks and pops now and then.

I'll fill the tub. Caulking in my swimsuit?. Or not!
Thanks so much!

Hey, I'm JazMan, you're Kari,

Yes I'm sure your tub is rockin. You might be able to fix that. Is there an access panel in the area behind the plumbing wall? Maybe a shim in the right place.

I've never used those caulk application thingys. Damp finger, small soft rounded sponge. Wipe in one direction.

Jaz