How to Install Cement Board and Ceramic Tile Over Vinyl Floor

Install the Cement Board

• 1). Lay the cement backerboard on the vinyl floor, leaving a 1/8-inch gap between each sheet. Place nails between the sheets of cement board to help you keep the gap consistent. Lay the cement board on the floor with the rough side facing up.
  
  
• 2). Cut sheets of cement backerboard to fit, using a 2-by-4-inch piece of wood as a straight edge and scoring the cement board 10 times with a carbide-tipped cement board knife. Move the wood under the cement board, lining up the edge of the wood with the cut. Press down on one side of the cement board to break it. Make a final cut with the carbide-tipped cement board knife.
  
  
• 3). Drive backerboard screws through the cement board into the vinyl floor below with a power drill. Place the backerboard screws every 6 inches along the edge of each board.
  
  
• 4). Cover the joints between sheets of cement board with fiberglass mesh tape, spread on with a taping trowel. Spread a thin layer of thinset mortar over the fiberglass mesh tape with a trowel. Allow the thinset mortar to cure for 12 hours.
  
  

Install the Ceramic Tiles

• 1). Measure each wall and mark the floor at the mid-point of each wall. Snap chalk lines between opposite marks, creating a cross on the floor. Trace the chalk lines in permanent marker, using a yardstick as a straight edge.
  
  
• 2). Dry-lay tiles on the floor along the lines on the floor, with tile spacers in between them. Rearrange the tiles if necessary to avoid having to place tiles smaller than 1/2 tile on one side of the floor.
  
  
• 3). Mark the location of each tile on the floor in pencil. Make additional chalk lines if you want a more detailed grid to guide you while you place the tiles. Trace the new chalk lines in permanent marker. Set the tiles and tile spacers aside.
  
  
• 4). Spread thinset mortar on a section of the floor close to the intersection of the lines you made in Step 1. Create grooves in the mortar by dragging the edge of a notched trowel over it.
  
  
• 5). Place tiles on the thinset mortar, using the lines on the floor as a guide. Place two tile spacers on each side of each tile to keep spacing consistent.
  
  
• 6). Repeat Step 4 and Step 5 until the floor is covered except for the edges. Place a beater board on top of the tiles and tap it with a rubber mallet to embed the tiles into the mortar.
  
  
• 7). Mark tiles for cutting by laying them on the floor next to the wall, and marking them on each side where they overlap the adjacent tile. Cut the ceramic tiles with a snap cutter. Place the cut tiles on the floor as you did the others, facing the cut edges toward the wall. Let the mortar dry for 12 hours.
  
  
• 8). Remove the tile spacers. Spread grout over the tiles with a grout float, filling the spaces between the tiles. Scoop up the excess grout with the side of the grout float as you work. Don't put grout between the tiles and the wall.
  
  
• 9). Wipe the grout residue from the tiles with a wet sponge, rinsing the sponge frequently. Draw the corner of a damp sponge along the grout lines, creating a consistent appearance. Let the grout dry overnight.
  
  
• 10
  
  Fill the space between the tiles and the wall with silicone caulk. This allows the ceramic tiles to expand and contract without cracking. Let the caulk cure overnight.