I have brand new grout in a shower done by a pro. Merely two months later it is already cracking. The contractor is telling me that house movement can cause this. (I'm not sure if he's full of it? Can house movements cause cracks in brand new grout? There are cracks happening in multiple directions which is odd for a presumably floated shower. Anyways, the house movement is the only thing I can think of, and my area is pretty notorious for it.
In any case, how would you go about fixing this? Would mixing more grout and driving it in work or would it be a waste of time. I'm really happy with the whole remodel but this is driving me nuts every time I'm in the shower.