How to Lay Tile in a Mortar Bed

Measure the length of two opposing walls in the room, using the tape measure. Divide the measurements by two to determine the center of the walls. Mark the center points on the floor where the floor meets the walls. Connect the two center points with a chalk line, then snap the chalk line against the floor to produce a solid line between the two points. Create a second chalk line between the two remaining walls, using the same method to create four squares or quadrants.

Combine thin-set mortar with water in a bucket, using the drill and paddle to mix according to the manufacturer’s directions.

Spread the mortar against both chalk lines of one quadrant, using the notched trowel. Create furrows in the mortar by dragging the notched edge of the trowel across the mortar bed.

Press the first tile into the mortar bed gently so the edges of the tile rest against the two chalk lines, where the lines intersect. Twist the tile slightly if you're laying tiles that are 8 inches or greater in size.

Tap the center of the tile a few times gently with a rubber mallet to firmly set the tile into the mortar bed.

Place a tile spacer against the edges of the tile to ensure even tile spacing.

Position tiles along the entire length of the mortared surface inside the chalk mark, using the same method. Remove the tile spacers are soon as you've installed adjoining tiles, as they are needed only to space the tiles evenly and are difficult to remove if left in the mortar and the mortar dries.

Place a straight piece of 2-by-4-inch board across the tops of the tiles and gently tap along the length of the board with the mallet to ensure the tiles are level in relation to one other.

Tile the area inside the mortared quadrant using the tile spacers as guides.

Lay tiles into the remaining three quadrants using the above method.

Mix a batch of grout according to the manufacturer’s directions. Add a release agent to the grout if you're installing unglazed or stone tile, again following the manufacturer’s directions.

Pour grout over a corner of the tile floor and spread across the tile, using the rubber grout float to fill grout seams between tiles. Tile the grout float at a 60-degree angle when spreading the grout and press the grout into the floor firmly to work it into the seams. Work outward from one corner of the room until you fill all grout seams.

Dampen a large sponge in cold water and wipe away excess grout. Work in 2-foot sections and rinse the sponge after each section. Allow the tile to dry for four to six hours.

Buff the tile with a clean cloth to remove haze. Apply grout sealer across the grout seams, using a sash bush or small sponge brush. Don't get sealer on the face of the tile. Wipe any sealer off the tile with a rag before the sealer dries.