Terrazzo is a hard, durable floor surface, just like ceramic tile. However, terrazzo has a somewhat dated look and must also be refinished periodically to maintain its appearance. It is possible to lay ceramic tile over terrazzo with the proper preparation and attention to detail. Terrazzo is made and laid in different ways and each requires a different pretreatment, tile mortar and tile grout selection to successfully put ceramic tile on terrazzo. Understanding the type of the existing terrazzo and tailoring the tiling process accordingly produces excellent and long-lasting results.
Things You'll Need
Plastic drop cloths
Self-leveling concrete or leveling resin
Strip the terrazzo of any surface wax or sealant with a chemical wax stripper in accordance with the manufacturer's instructions.
Tape off all doorways leading from the terrazzo area into other parts of the structure by hanging plastic drop cloths in the doorways and securing them to all three sides of the doorway and to the floor with masking tape in preparation for sanding the terrazzo. Turn off all air conditioners, heaters, air conditioning or ceiling fans to keep the terrazzo dust from disbursing during sanding.
Put on protective eyewear and a respirator mask to protect yourself from terrazzo dust and sand the surface of the terrazzo to rough up the otherwise polished surface, using either a commercial or hand-held sander.
Vacuum as much of the terrazzo dust as possible, then damp mop the floor to clean up the remaining dust.
Remove the drop cloth barriers to the other parts of the structure to aid ventilation, and remove the protective clothing if working with concrete in Step 6. If working with epoxy resin, keep the respirator on.
Level any sloping area of the terrazzo with self-leveling concrete for concrete-based terrazzo, and with leveling resin for terrazzo made with epoxy resin. Allow the leveling material to cure according to manufacturer's instructions before continuing.
Purchase tile adhesive and grout that are chemically compatible with the type of terrazzo to be tiled over. Terrazzo made with epoxy resin requires different epoxy resin-based adhesive and grout for proper bonding, and terrazzo made with cement requires cement-based adhesive and grout. This is applicable also for any leveling material used on the terrazzo.
Apply the tile adhesive with a notched trowel as normal.
Set the ceramic tile as normal, cutting and sawing the tile as needed to conform to the room contours and any obstructions in the floor. Allow the adhesive to cure 24 to 48 hours according to manufacturer's instructions before continuing.
Mix the grout according to manufacturer's instructions and apply it to the seams between the tile with a grout float. Allow the grout to cure before continuing, about 15 to 30 minutes.
Fill a bucket with water and wet a large sponge. Use the sponge to wipe up the excess grout and remove any film left on the tile surface. Rinse and squeeze the sponge as needed to keep from redepositing while working across the tile surface.
Wipe the tile again with the damp sponge to ensure all grout film and residue is removed, as any grout film left on the tile surface eventually becomes permanent if not removed.