Steve Roberts
Lizzie, you need to sort this asap!! Replace the grout around the bubbling tile,(if it moves when you stand on it, consider lifting it up and replacing it) and where the other gaps in the grouting are appearing. Grout is relatively cheap to buy, mix and apply, if you don't do it, it will only get worse leading to adhesive failure, and cracking/lifting of the tile. I hope the room has been suitably waterproofed, if it has you should be ok as this should hopefully stop any water penetrating the walls & floor. As for the gaps between wall and floor where they meet, they should have been silicone, not just grouted. If this is the case , go and buy some BAL silicone from topps tiles or other outlet, it comes in different colours so you can match it with the colour of the grout . Apply silicone to all corners ( the entire length) of wetroom/ sower area Kind regards Steve @ Greenleaf tiling
