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How to Install a Modular-Design Tile Floor

Learn how to install a modular-designed tile floor in any room.

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Step 1: Choose the Tile

Choose the size and type of tile for the installation.

Tip: A good place to start is a manufacturer's showroom or a tile retail store. Experts there can help with the right tile choices, colors, and the correct amount of tile needed. Bring along a rough sketch of the room with proper dimensions. A photograph of the room can also be useful in choosing tile colors.

Two of the most popular types of tile are ceramic and porcelain. Ceramic is a clay body with a glaze on top. Porcelain tiles are gaining popularity because of their durability. All of these products are semi-manufactured and are not complete until they're installed on a floor. This gives the chance to determine what it will look like.

Step 2: Check the Subfloor

The minimum requirements for tile installation are a 3/4" plywood subfloor on a maximum of 16" center floor joists. If the joists are further apart, or there is a bounce to the subfloor, install a second layer of plywood.

Step 3: Choose the Backer Board Material

Do not install tile directly onto the plywood subfloor. Install an underlay material first. Choose the appropriate backer board material for the underlay. There are basically three types of backer board material. There is the cement-based backer board that has fiber incorporated into it. There is cement based with a glass fiber mat. And, there is a relatively new material on the U.S. market called an "uncoupling membrane", a polyethylene membrane with a grid structure of square, cut-back cavities and an anchoring fleece laminated to its underside. It has a waffle design. Lay the thin-set mortar on the waffle and place the tiles on that. It creates a mechanical bond that locks in that tile. The uncoupling is what is used in this installation.

grid structure with waffle design for underlay

Step 4: Mix the Mortar

Mix the latex modified thin-set mortar according to manufacturer's directions to a consistency of cake batter. A good way to mix mortar is with a variable speed drill and a paddle mixer attachment.

use paddle mixer attachment on drill to mix mortar

Step 5: Roll Out the Material

Roll out the uncoupling material and pre-cut strips to fit the room dimensions.

Step 6: Lay Down Underlayment

Start along one wall of the room and apply the thin-set to cover the width and length of the first strip of uncoupling underlayment. Lay down the first strip of underlayment over the mortar and press down firmly to seat the underlayment to the mortar.

Tip: Investing in an inexpensive pair of knee pads will make the tile installation a lot more comfortable on the knees.

underlayment used over mortar for strength

Step 7: Measure the Room

Once you choose the layout and design, measure the length and width of the room and multiply for the room's square footage to figure out the amount of tile needed for the job. If using square tiles, order 5 percent extra and if using a modular-type layout, order 10-12 percent extra.

In the pattern here, there are 3/16" spacers. The manufacturer modulated this tile so that three tiles plus two grout lines will equal the large tile, and two tiles plus one grout line will equal the middle size tile.

figure square footage of room to order tile needed

Step 8: Mark the Underlayment

To find the exact center of the room, measure the length of the room, divide by two and place a mark onto the underlayment. Then, measure the width of the room, divide by two again and place another mark onto the underlayment. Pop two chalk lines at the marks on the floor. The exact center of the room is where the two chalk lines intersect.

Step 9: Place the Tile

Place the first tile down and mark the center for each side of the tile with a pencil, lining up these marks along each chalk line.

Step 10: Mix the Thin-Set Mortar

Mix more thin-set mortar the same way as before, only this time the consistency will be thicker -- much like the consistency of peanut butter. The thicker consistency will help support the weight of the tiles.

Step 11: Set Tile on the Mortar

Apply the thin-set directly onto the underlayment using a 3/8" x 1/4" U-Notch trowel and seat the tile on top. Remember to work in a small area and don't back into a corner because once the tile has been set, it cannot be walked on and will need to cure for 24 hours. Work from the back of the room toward the front.

use a u notch trowel with thin set  to seat tile

Step 12: Cut the Tile

As installation progresses and you reach a wall or an obstruction, cut the tile to fit into a smaller area. There are two main ways to cut tile: with a scoring board (Image 1) or with a wet saw. The scoring board has a cutting wheel on it and it will put a small score in the tile. Put some pressure on it and it will snap at the score line.

Use nippers to trim any uneven cut. For more precise cuts and cuts with angles, use a diamond wet saw. A diamond wet saw (Image 2) uses water to cool the friction when cutting the tile.

Tip: Both cutting machines can be rented at a tile retail store. Measure and mark all tile cuts beforehand and then rent either the tile scorer or wet saw and make all cuts at once. The wet saw rents by the hour, so measuring and marking all complicated tile cuts will help save money and time.

Step 13: Apply Grout

After the tile has cured for 24 hours, the grout can then be applied.

Note: Some ceramic and porcelain tiles will have to be sealed prior to grouting as the pigments in the grout will stain the tile surface. The installation is a porcelain tile with a feature crossed "Cross-Sheen" -- a process by the manufacturer where the sealant is fired into the surface of the porcelain tile.

Tip: Use a pair of needle-nosed pliers to remove the spacers. Some thin-set may push up between the tiles. To remove this, use a utility knife to clean out the line. The grout lines need to be all the same thickness because it will create a more consistent color when the grout dries. Moisture affects the curing time of grout, the more even moisture content -- the more even the color.

use utility knife to clean excess thin set

Step 14: Choose the Grout Color

It is best to select the color of the grout when choosing the ceramic tile. Pick out a color that is in the tile. Choose a color of grout that will complement the tile color. A dark grout color will accentuate an uneven grout line, so a lighter color is often the best.

select grout to compliment tile color

Step 15: Mix the Grout

Mix the grout the same way as the thin-set mortar -- with clean water and a 5-gallon bucket. The consistency should be like peanut butter. Let the mixture stand for 10-15 minutes (this is called "slaking" and the wait time allows the moisture to soak through any unmixed powder).

Step 16: Apply the Grout

Apply the grout to the tile using a grout float, working it diagonally across the tile surface and applying pressure to force the grout into the joints. Try not to go perpendicular to the grout line because the float can fall down in and gauge the grout. Cover the entire surface of the room with grout and let dry.

Tip: Don't leave too much behind because you will have to go back and clean it up later.

force grout into the joints with grout float

Step 17: Clean Tile Surface

After the grout has dried thoroughly, go back over the surface with a damp sponge and wipe off the excess grout. Rinse sponge out frequently until the tile surface is clean. This process may take several applications of clean water to remove all of the grout.

Step 18: Seal the Grout Lines

Buff out the last bit of grout haze with a dry paper towel and seal the grout lines using a grout sealer once the grout has cured. The grout sealer can be purchased at any home center -- just follow the manufacturer's directions.

buff out the last bit of grout haze

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