How to Install Ceramic Tile Over Floor Glue

Many subfloors are covered with glue when linoleum, vinyl, or carpeting is installed. This glue does not make a good surface for ceramic tile adhesion. Cement backerboard protects the floor from potential water damage if the tile or grout becomes damaged. Backerboard is also an easy way to install floor tile over glue without removing the glue.

Things You'll Need

• Measuring tape
• Cement backerboard
• Pencil
• Tile saw
• Notched trowel
• Thin-set mortar
• Fiberglass mesh tape
• Chalk line
• Grout
• Rubber grout float
• Sponge

Instructions

1. Measure the length and width of the room with a measuring tape. Transfer the measurements to a piece of cement backerboard with a pencil. Cut the backerboard to size with a tile saw. Cut as many pieces as needed to cover the floor where you'll be tiling.

2. Use a notched trowel to apply thin-set mortar to the floor, over the glue. Once the mortar is on the floor, set the cement backerboard pieces on the floor and screw them into place. The backerboard will cover the glue and prepare the floor for the tiles.

3. Lay fiberglass mesh tape on the cement backerboard seams. With the flat edge of the trowel, apply thin-set mortar to the top of the mesh-covered seams. Let the mortar dry overnight.

4. Measure the length of the room with a measuring tape. Mark the middle of the length of the room with a chalk line. Repeat with the width of the room. You will have two lines that cross at the middle of the room.

5. Use a notched trowel to apply thin-set mortar to the top of the cement backerboard. Begin spreading the mortar at the center of the room at the intersecting lines. Place the tiles on the thin-set mortar. The tiles should be placed beginning at the center of the room, along the lines. Place all of the tiles. Use a tile saw to cut the tiles to size as you go. Let the floor sit overnight to dry.

6. Grout the floor by spreading a small amount of mixed grout on top of the tiles, using a rubber grout float. Once the tile joints have been filled with grout, remove the excess grout. The rubber float can be used to remove the majority of the grout from the top of the tiles. A damp sponge can be used to remove the residual grout from the tile.