Hi I moved in to a recently renovated home one year ago. The kitchen had new ceramic tiles installed, with sanded grouted filled in the 5/8 inch joints. I sealed the grout after moving in as I was told that had not been done. Recently I noticed the grout along a line of tile edges has cracked and the crack runs the width of the kitchen. I am noticing grout fissures/cracks running in another direction as well, again along the edges of the tiles. I have read this could be a sub floor issue. Aside from having the tiles removed and the sub floor addressed (if that is the issue) are there any other options? Can I remove the cracked grout and just re-grout?

To Start a Ceramic Tile Project:
1st: Figure out the Size of the Room-Length x Width. This will give you the suare Footage of the Room, and will Determine the amount of Materials You will need for Preparation of Floor before Tile Installation.

2nd: Pick out the size of Tiles, and the Color you wish to Purchase(Decide if it is a High Traffic Area) Tile Comes in different Grades, and if a High Traffic area, you will need a Higher Grade Tile.

3rd: Materials needed for Preparation- Hardy Backer Board(1/2"-3' x 5'). HardyBoard Screws, Unsanded Mastec, Spacers-Depending on Tile Spacing/size of Tiles, 1' x 4' boards. (Tools Needed- Drill, Chalkline, Measuring tape, 3/16 x 3/16 Trowel, 1/4 x 1/4 trowel).

Installation; )Preparation) 1- Apply a 3/16 x3/16 trowel of Unsanded mastecon floor before laying the Backerboard. Screw the Backer Board to the floor recessing screws. (Never have Backerboard meet with 4 pices meet together, off set each piece of backerboard during Installation). After sweeping the room, use a trowel to fill screw holes with unsanded Mastec. Tape all Joints and fill with un-sanded Mastec.(Let Dry for 24 hours).

Tile Installation:- 1st- Sand Mastec used for joints, and screw holes. 2nd- Sweep roome very good and vacuum very well. 3rd- Measure each wall to find the Center Point of the room.(I prefer nailing a board down across one side of the line to keep tiles straight, and butt tiles to the board, and put spacers in between tiles). I use a 1/4" trowel to butter tiles before laying. With using Spacers, buttering tiles, laying tiles.( I prefer using a 2 x 4 and tap tiles across with a rubber Mallet to keep all tiles same heigth). Let One side tiles laid for 24 hours. 4th- Then do the same thing with other side of line.

Finishing Project: Once all the tiles are set, and all spacers removed. Mix up color of Choice unsanded Grout, and follow Manufacturers mixture Specs. Use grout Float and fill Spacing between Tiles. Let dry for 15 minutes. Use bucket of Clean water and Big sponge rinsing frequently removing all Grout from Tiles. Let dry for 30 minutes, and clean tiles again with Clean Water. Let set overnight. Next day, take Clean towel and rub haze off the tiles. Lastly, Seal Tile and grout.

Enjoy your project, and the Satisfaction of doing it yourself. Hope i was some help!!