Before you can install new ceramic tile over existing ceramic tile, you’ll need to do some surface preparation.
The first step is sanding the old tile with 100-grit paper to rough up the surface.
Next, apply a bonding primer to the surface.
To fill the grout joints in the old floor, mix up a floor-leveling compound. This material is a relatively thin liquid when it goes on, so it will flow into the low places and level itself.
Trowel it over the old tile to fill in the grout joints so that once it’s dry, you have a completely flat, level surface across the whole bathroom.
From this point, the process is much like any ceramic tiling. Chalk layout lines along the longest dimension of the room and begin applying thinset mortar with a notched trowel. The thinset acts as glue to secure the tiles to the floor.
The chalk lines and plastic spacers help maintain straight lines and consistent spacing.
Once the tiles are in and dry, apply the grout with a rubber float before we clean off the excess material, revealing our new finished tile floor.