How to Tile Over a Subfloor
Depending on the location and design of your house, the subfloors in your rooms may be made of either concrete or wood. If you would like to tile over a subfloor, you must take into account the subfloor's surface material. The tile-laying process is substantially the same regardless of the base material, but the preparation is slightly different for concrete and wood subfloors--using the correct approach yields better end results. Does this Spark an idea?
Things You'll Need
- Level
- Wood filler
- Putty knife
- Sandpaper
- Plywood underlay
- Concrete screws
- Drill
- Tape measure
- Chalk snap line
- Tiles
- Tile adhesive
- Tile spacers
- Tile cutter
- Grout
- Grout float
- Rag or sponge
Instructions
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Prepare the subfloor. If the subfloor is wood, place a level on the floor in one corner and scoot it across the floor toward the opposite corner, checking every few inches for any dips or high spots; mark where they occur. Fill dips in with wood filler, using a putty knife. Allow to dry, then sand down to make the filled area flush with the subfloor. Sand any high spots on the wood floor down. If the subfloor is concrete, install a plywood underlay. Lay the sheets of plywood over the concrete so they fit tightly and cover the entire area. Drill concrete screws through the wood along the edge of each sheet every 4 inches and into the concrete.
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Find the center of the prepared subfloor. Measure the length of the longest wall and mark its center point, then measure and mark the center of the opposite wall. Snap a chalk line between the two center points to create a line down the center of the room. Repeat the process with the remaining two walls to create a cross in the center of the room that marks the midpoint.
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Lay out the tiles. Lay the first tile in one of the four corners created at the intersection of the two chalk lines in the middle of the room so that two of its edges line up with two of the chalk lines. Pick up the tile and apply tile adhesive to the floor beneath it with a putty knife. Press the tile down firmly into its original position and into the adhesive.
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Place tile spacers on all sides of the first tile. Lay additional tiles against the sides of the first tile. Continue placing tiles, working outward from the first tile and using spacers between each tile. Once the floor is covered with as many full tiles as it can hold, pick them up one at a time and spread adhesive under them, then replace in their original position. Remove the spacers as soon as you press the tiles into the adhesive.
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Cut tiles down to fit into the remaining space between the last full row of tiles and the room's walls using a tile saw. Apply the tiles with adhesive. Allow the tile adhesive to dry for 24 to 48 hours before using the room.
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Mix a batch of grout that matches the color of adhesive you used. Spread grout over the tiled floor with a grout float, making sure to fill in all spaces between every tile, and wipe off any grout that gets on the surface of the tiles. Let the grout dry for 24 to 48 hours before walking on the floor. Wipe off any excess grout on the surface of the tiles with a wet rag or sponge.
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Tips & Warnings
When installing underlay, drill the screws to 1/4 inch below the surface of the underlay, then fill in the space over the screw heads with wood filler to create a flat, even surface.
References
- Photo Credit Jupiterimages/Comstock/Getty Images
