See pictures, my husband installed this shower himself before we got married (against my suggestion that a professional do it....for this very reason). The grout seems to be cracking in high water areas but fine higher up in the shower where it doesn't get a lot of direct water. What would be the cause here? Grout not made up/mixed properly?? He thinks it is just the house shifting but I'm skeptical because it's only cracking in high water areas of the shower. How can we fix this? ...he's tried going over and over it with a commercial grade sealant...which doesn't work. The shower leaks like a sieve so we don't use it. Also wondering if we chose a shower faucet with a flawed design? ....tiled up to it then silicone sealed around the edge. Large gap in top for moisture to get inside but maybe this is fine???