Don't use the premixed stuff, pick up some grout that you mix with water and
just follow the directions. I just did the same thing. It worked fine in
the shower. I probably let it dry for about 4 hours before letting it get
wet. Vinegar is useful for getting the powdery stuff off the tile.

Drew Morton wrote:

I recently had to do some work to my shower drain, and in the process had
to
dig out some of the grout. No problem, I thought, ill just regrout when
Im
done. I went to HD, bought some pre-mixed grout, and had at it. Cleaned,
dried, and basically followed the directions. After the appropriate
drying
time, I used the shower again, and the grout ended up all mushy. I
cleaned
out the grout again, re-grouted, and let dry even longer. The grout was
hard and dry, and I used the shower again. Same results. Mushy grout.
Is there a specific grout that I should be usung for these very wet
conditions? I looked at all the different grouts, and none said anything
about being specifically for showers or baths.

Thanks in advance,

Drew