Cracks, Small Repair or Larger Problem?
When your existing floor or wall starts to develop cracks whether in the grout, tile, or both, you need to look into the depth of your problem. Small cracks in grout especially when transitioning from tile to wood will occur after time and should be repaired. However if cracks travel across the face of one or more tile(s) you may have a deeper problem.
Cracks that travel across multiple tiles occur when there is continuous movement in the floor under your tile. The best way to repair these type of problems is to start from the bottom and work your way up.
Begin by cutting out the grout around the tile/tiles you plan to remove. Carefully remove your damaged tile taking care not to disrupt the surrounding tile. You should then remove the old sertting material all the while taking notice of the area under the cracks in the tile. Once this area is clear you will want to attempt to screw the underlayment to any joists to stop any movement or creaking in the floor. If you find that there is a “seam” where the underlayment peices come together you may want to use a crack preventitive before installing your tile.
Remember to clean the grout surface immediately surrounding your work area before grouting your repaired area,(this will help the new grout to match the old grout of the same color)