A concrete floor must be thoroughly cleaned before laying tile on top of it - any old paint, fillers, glues or sealants need to be removed prior to tile installation. Also be sure to remove any dust, mop the concrete floor with water and allow it to dry completely. If the concrete floor is smooth, treat it with an acid based solution to roughen it up before you lay tile on top of it.
Be sure to fill any holes and smooth out any bumps on the concrete floor before laying tile on top of it (use a floor patch and leveler compound from your local home improvement store). Use a leveler to ensure the surface is flat.
Find the center of the concrete floor and 'dry fit' the tiles to see if the pattern ends similarly on the edges. Use a pencil to mark vertical and horizontal lines where appropriate. You want the tile size to be consistent as they approach each end point when laying tile on a concrete floor.
Apply the tile adhesive with the notched trowel, starting in the middle of the concrete floor. Lay the tiles in the adhesive and place the spacers in-between each tile as you go. Be sure to give each tile a little twist to ensure a good bond with the adhesive. Cut the tiles as needed to fit on the ends. You can also use sandpaper to smooth out the tile edges if they are sharp after you cut them.
Let the tiles dry in the adhesive overnight.
Remove the tile spacers and mix the grout according to the manufacturer's directions.
Using the rubber float, apply the grout to the tiles at a 45 degree angle. Wipe off excess grout with a wet sponge.
After about an hour, check for grout haze on the tiles and wipe them clean as needed.
Seal the edges with mildew resistant caulk if you are tiling on a floor that may get wet like the bathroom or kitchen.
See the Resources listed below for more tiling and home improvement ideas.
Things You Will Need
- tiles and spacers
- tile adhesive
- floor patch and leveler compound
- notched trowel
- tile cutter
- rubber float
- acid based solution for roughing up the concrete
- knee pads
- If the space between your tiles is wider than 1/8 inch, use sanded grout for a stronger hold. Otherwise you can use non-sanded grout.
- Make sure you use a waterproof grout if you are tiling in an area that will get wet. Apply grout sealant as desired.