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How to Lay a Ceramic or Porcelain Tile Floor

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How to Lay a Ceramic or Porcelain Tile Floor

Laying a ceramic or porcelain tile floor can be considered a daunting task, but with adequate planning and preparation, this perception can be overcome. Laying one's own tile is also much less expensive (and possibly more rewarding) than having it professionally installed. Cost can be minimized, again, by careful planning and preparation.



Planning and Preparation
Evaluate the space to be tiled. A first phase of evaluation is to determine the size of the room to be tiled (or re-tiled). Using a tape measure or digital laser tape, measure the room from one wall to the opposite wall, and note the distance. Let's say the measure of this distance is 12 feet. Now measure the distance of the opposing walls to each other. Let's say this distance is 7 feet. Multiplying these 2 distances (12 feet x 7 feet) will yield a total area of 84 square feet. Note: These measurements are based on squared dimensions. If the room is not perfectly "squared" (or in this case "rectangle") because of an irregular floor plan (where there might be a small section off of one side, for example), do not factor this space into your measurement. While you will of course need to tile this space, factoring this space into your measurements will affect finding the "center" of the room, which will be discussed shortly. This area is important to note, since it will provide you with an estimate of the number of tiles you will need to purchase to cover the area to be tiled. The number of tiles you will need, however, will depend on the size of the tile you wish to lay, as well as the tile pattern you will like on the floor.
Decide on your tile size and pattern. Tile comes in different sizes: 4inch by 4 inch, 8 inch by 8 inch, 12 inch by 12 inch, for example (there are others, too). Tiles can also be laid in different patterns. The total number of tiles you will need will depend on the size and pattern you want. For simplicity's sake, let's assume we are going to use 12 inch by 12 inch tiles and use a traditional grid design, where tiles are simply laid in pattern like graph paper. Because the area of the room is 84 square feet, we will need about 84 12 inches x 12 inch (1 square foot) tiles (even accounting for the spaces in between tiles, known as "joints"). However, it is a good rule of thumb for beginners to purchase extra tiles to account for improperly cut or scored tiles, or for breakage. Buy an extra pack or two of tiles to be safe. When laying tile diagonally, a lot of material is wasted as cutoffs. A good rule of thumb here, even for experts, is to buy 15% more tile than the square footage would dictate.
Pick a color. You are only limited by your imagination (and the store's stock). Choice of color typically is a matter of individual choice. The only additional step of planning and preparation with regard to color of the tile is with the grout selection. Grout is the "filler" that goes in the spaces between tiles, the joints. It can be grey, white, terra cotta, and so on. Typically, dark tiles with light grout really show the spaces in between tiles, and vice versa. The selection of grout color will really depend on how you would like the floor to look to the eye. There is no hard and fast rule.
Prep your space. Be sure that the entire surface is as smooth as possible. You will likely need to use floor leveling compound (available at your do it yourself hardware store) to float (create gradual transitions in the floor's surface) out any divots, holes, or differences in sub flooring heights. If you don't "float" out these differences your tile will crack. Your surface is now prepared for tiling.

Setting Up

Find your center point. You have already determined the size of your room, which is 84 square feet. But you need to find the center point. Finding the center point is critical for laying the tile. It will determine where you will lay your first tile and the next ones. Measure one wall, for example the 12 foot wall. At 6 feet, half the distance, mark a point with a pencil. Do the same on the other 12 foot wall. Using your chalk line, anchor one end at the midpoint of one wall and stretch across to the midpoint of the other. "Snap" the chalk line by lifting it up slightly and letting it hit the ground; this will leave a straight line on the floor. Measure the 7 foot walls and mark a point a 3 ½ feet on both sides. Follow the same process with the chalk line. Where the lines cross or intersect should be you center point of the floor.
Rehearse laying out tiles. When you have found your center point, you will notice you will have a "quadrant" design on the floor, or 4 equally sized areas. Starting at the center, "rehearse" your tile pattern by simply laying them on the floor without any adhesive or glue. Place the first tile at the corner nearest the center point. You are only going to work in one quadrant at a time. Begin placing tiles in a straight line towards either wall, leaving a small space in between the tiles. When you begin laying tiles with adhesive, you will use tile spacers to provide uniform joints between your tiles. For now, leave a space approximately the size of the tile spacers you will use (either ¼ inch or ½ inch, depending on your preference for joint size). After you have laid a row of tiles in one direction, lay a row of tiles in the opposite direction, and continue following this pattern until you set the last tile in the corner "kitty-corner" from the center point. For tiles abutting, or closest to, the walls, you will notice you will have to either cut them or slightly realign your center point. Most people decide to cut rather than realign, depending on whether or not those tiles will be visible to the eye. Let's take a look at this point to alleviate any confusion. In a 12x7 room, the center point is at the intersection of 6 feet and 3 1/2 feet in the middle of the room. Your tiles are 144 square inches, or 1 square foot. At first, it may seem like the space working in one quadrant will only require 6 full tiles by 3 full + ½ tiles (since that is the measurement of the quadrant and since your tiles are exactly 1 square foot). However, you will have to account for the size of the spaces, or joints, between the tiles. For simplicity's sake, let's assume you would like joints ½ inch wide between tiles. For the 6 foot line, you will end up with 5 joints (plus the joint between the wall and the last tile). Therefore, you will only fit 5 full tiles and will need to cut the last tile. Your joints on this line will account for 2 ½ inches of total size. If you include the wall joint, that will equal 3 total inches. Thus, the last tile will need to be cut at approximately 9 inches, where 12 inches minus 3 inches for the joints yields a 9 inch final tile. Some people do not prefer this method, but would rather choose to realign the center point in order to minimize cutting tile, especially if the wall where the tile abuts is highly visible. The choice is yours. Typically, this is only done if the final wall tile is less than half the size of the whole tile (in this case, less than six inches). In those cases, the convention is to shift the row of tiles back a distance half the tile's width. In this example, the wall tile is 9 inches, so there may be no need to realign, But again, it all depends on your personal preference and how you would like the final to look.
Repeat the same process for the 3 ½ foot line. You will use 3 full tiles and 1 tile cut to 4 inches, since the size of the 3 joints plus the 1 wall joint equals 2 inches and your original tile size was 6 inches (6 inches original tile- 2 inches total joint= 4 inch tile). Note that this does not follow the realignment strategy mentioned above. Because this room is "squared," the true center is best left where it actually is. Simply make uniform cuts as they correspond to each side (in this case, you will have 9 inch tiles as the wall tiles on the "short" 7 foot walls and 4 inch tiles on the long 12 foot walls.
Follow the same process for the other three quadrants. Because this design is uniform, it is best to follow the same size cuts all the way around.
You will also need to pre-drilled some tiles to fit over items such as radiator pipes, bath pipes, waste pipes etc. Your floor will look better if you can drill a hole in the tile and lay the tile over the pipe. To achieve this you may have to drain down radiator systems, remove the rad from the wall and take the taps off the pipework. Very time consuming but worth the effort if a minimal look is desired. Use a diamond hole saw to bore into the tile and drill a perfect hole.
When you floor is rehearsed and all tiles are lain, measured, and cut, and appear to your liking, you are ready to lay the adhesive,

Spreading Adhesive, or Mastic, and Laying Tiles

Pick up all tiles and set aside. On your prepared surface, begin spreading the adhesive with the notched trowel. You will start from the center point, work only in one quadrant, and apply small sections at a time, following the pattern during the rehearsal. Spread adhesive evenly, then using the notched edge, make a raking motion. You should have grooves neither too deep nor too shallow. Set the first tile in place at the corner lines made by the center point. Do not twist tile; simply press the tile down firmly yet softly. Set tile spacer and then continue with additional tiles. (Remember to set tile spacers after each tile). Use your level to determine degree of level of the tiles as you go along. (Not all surfaces are perfectly level!). If slightly uneven, either manipulate the tile or add a little more adhesive to the floor until level. Usually, after a quadrant is complete, remove the tile spacers so they do not set into the adhesive. Follow this process for the remainder of the floor, making sure to check the level as you go along..
Wait. After the tiles have been set, it is usually advised to wait at least one day (or overnight) to allow the adhesive to dry, or cure. After the adhesive has cured, you will grout the joints.


Continue working in quadrants as before. Using a rubber float, apply only enough grout as you can effectively work with . In a diagonal direction, press grout into the joints to an even level with the tile. Skim excess from tile with the rubber float. You will notice a mild "grout haze‿ on your tiles. Use a damp sponge to remove grout haze from tiles, making sure not to press too hard on joints. Continue this process with other joints in remaining quadrants.
For joints at the wall and floor interface it is best to use caulk instead of grout. There are benefits to using caulk along wall joints. All tiles may expand or contract depending on temperature fluctuations. The wall joints are also known as expansion joints. Using caulk here will buffer expansion and contraction a bit.
After grouting is complete, you are practically done. Wait for the entire floor to cure for about a week before giving it a good mopping to remove remaining grout haze. You may also choose to seal the grout with a sealer to lock out dirt and or grease.


You can determine the accuracy of the right angle (90 Degrees) center point by following a simple measurement (based on the Pythagorean theorem, which will impress your friends when you bring it up in conversation). From the center point, measure out in one direction exactly 3 feet and mark a point. From the adjacent line, measure out in the other direction exactly 4 feet and mark a point. Then, taking a measuring tape, measure the distance between those two points. It should be exactly 5 feet from the points, where the tape measure resembles the hypotenuse of a right triangle. Remember, Pythagoras' theorem states that side A squared (3 feet x 3 feet= 9) plus side B squared (4 feet x 4 feet= 16) equals side c squared, 25 feet. The square root of 25 is 5 feet, or the distance you should see between the two points. If the hypotenuse does not equal 5 feet exactly, re-measure the walls and re-snap the chalk lines. The room is likely not square. Splitting the difference will make this fact less obvious once the tiles are in place.

Things You'll Need
Tile (as determined above)
Tile adhesive or "mastic"
A notched trowel
A tile saw or a tile scorer
A diamond hole saw to cut out radiator pipes and other holes
rubber float(a putty knife will scratch the tile face)
Tape measure (or digital laser tape)
Bucket (with warm water)
Chalk line
Tile spacers