Things You'll Need
Circular concrete sander
Rubber grout float
Installing tile over painted concrete adds a few extra steps to your tiling job. Unfortunately, the tile cannot be adhered directly to the painted surface. Paint used on concrete will not bond with the tile adhesive. All paint will need to be removed before you begin installing the tile. Once the concrete floor is paint-free, the tiling process is similar to most other floor tiling jobs.
Rent a circular concrete sander from an equipment rental store. Using the sander will generate a lot of dust. Tape off all air vents and doorways. Open a window and use a fan to blow as much dust as possible outside during the sanding process.
Vacuum up all loose dust, debris and paint residue. Go back over any spots that have remaining paint with your floor sander. You need a completely clean surface to begin installing the tile.
Find the center point of the room. Measure the midway point between two opposite walls. Snap a chalk line between these two points. Lay out a row of tile along this line and a row of tile running perpendicular to this line. Make sure these initial tiles are visually centered in the room.
Begin adhering your first two rows of tile. Use a thin coat of tile adhesive on the back of each tile. Once the tiles are in place, use a rubber hammer to set the tiles firmly into the adhesive. Wipe up any glue that seeps up between tiles. If you are new to tile installation, use grout spacers to lay out and set your tile.
Continue setting whole tiles until you reach the perimeter of the room, firmly setting the tile with a rubber hammer and wiping up excess adhesive from the sides and fronts of tiles.
Cut the tiles for the perimeter spaces using a tile cutter. Mark the tiles for cutting with pencil before using the tile cutter. Remember to plan space for grout along the edges of the room. Grout lines along the edge should be the same size as grout between tiles for the uniform appearance.
Mix grout to the consistency of toothpaste. Use a rubber grout float to spread grout into the space between tiles. Clean up grout from the tops of tiles with a wet sponge. Allow grout to set for seven days before applying grout sealer.