30 Tips for Floor Tile

As a building material, tile provides limitless design options and has done so for thousands

of years. When made of ceramic, porcelain or natural stone, tile makes a reliable floor covering because it does not burn, fade or easily stain when properly installed. Ceramic tile is water-resistant, stands up to wear, and can feasibly last as long as the substrate that supports it. Whether you hire out the work or attempt to tackle the installation yourself, the following are some helpful tips to keep in mind for your next tile project.

Place Your Order

Research the types of tile available for your project. For flooring, vitrified tiles are best because they're durable and can withstand heavy traffic. Vitrified tile is a ceramic tile with low porosity often used outdoors due to its frost resistance. Porcelain tiles fall under the category of vitrified tiles.

For outdoor floor tiles, ceramic tile manufacturers offer a wide variety of slip-resistant flooring options for any application.

Size matters. Large format tiles lend a more spacious look to a large living space, but the tiles should match the room size. Large tiles in a smaller room can make the room look even smaller. If this is the case, use medium size tiles. When remodeling a small bathroom,

most designers recommend using small tiles, because large tiles can make the room feel crowded and cramped.

Always purchase an additional 5 to 10 percent more tiles than you need for coverage. The extra material takes care of cuts and breakages during installation. Most companies will offer a refund on unused boxes of tile.

Tiles are available glazed or unglazed. Glazed tiles have a layer of liquid glass added to the tile prior to the firing process. (Note that for unglazed tiles, some grouts recommend use of a grout-release agent to prevent staining and make cleanup easier.)

You have options for floor-tile adhesive. Ready-mixed thinset mortar might be easiest to use for DIY'ers because it can be used straight from the container. Powder thinset mortar must be mixed with water but is less expensive, making it more economical for large floors.

Ask your flooring supplier which adhesive will work best for a given application. The type of tile, where the tile will be installed, and the type of substrate are all important factors.

What Type of Flooring Can You Put Over Ceramic Tile?

It's important to choose the right mortar trowel for the job. Generally speaking, most standard size floor tile installed with mortar will require a 1/4-in. square-notched trowel.

For 16-by-16-in. or larger tiles, choose a larger trowel with notches at least 1/2 inch deep. For mosaic sheets, use a 3/16-in. V-notched trowel to spread the adhesive. However, trowel size really should be selected based on what size provides the required coverage and mortar thickness for your application.

You also have options for grout. Use sanded grout for joints from 1/8 inch up to 5/8 inch to resist cracking and shrinkage. Use unsanded grout for grout joints up to 1/8 inch. Use only unsanded grout with glass, polished marble, or metal tile to avoid scratching the tile. Acrylic grout is a great option for wet areas like decks and showers because it’s mildew-resistant and retains color well. Epoxy grout is less DIY-friendly than other types, but it doesn't need to be sealed.

Avoid using too much water when mixing grout, which could weaken the grout joints.

Buy extra grout to make sure you'll have enough to complete the project, and always read and follow the product instructions carefully.

Plan to include a radiant heat system? If so, now is the time to explore the many low-voltage systems that work well to heat an otherwise cold tile floor.

Research the latest tile floor innovations when planning your order. For example, an uncoupling membrane such as the Ditra underlayment from Schluter Systems allows the tile to move independently of the subfloor, preventing cracks and breakage. Ditra-HEAT is a hardwired radiant floor-heating system that can be easily integrated into the uncoupling layer to warm the tiles.

Prep Steps

For floor tile, check the subfloor for level and flatness. Checking for level is particularly important if you’ll be adding wall tile. Set a 4-ft. level on a long straight board to read over

a large area. Swivel the board to find dips or bumps. The floor doesn’t have to be perfectly

flat, but the requirement is typically no more than 1/4 in. variation in 10 feet and no more than 1/16 in. variation in 12 inches.

For uneven concrete, it might be necessary to grind down the surface or apply a self-leveling underlayment to flatten the subfloor.

Plywood subfloors with high spots can be belt-sanded. Tile should be installed over a rigid underlayment that resists swelling and contraction, which can damage the finished floor. For

plywood subfloors (minimum 19/32 in. thick), cement-board works well for a tile underlayment.

You can ensure a durable subsurface for tile over plywood by installing fiber-cement board as an underlayment.

Stagger any joints between cement-board panels (and avoid aligning them with the subfloor joints). Leave an 1/8-in. gap between the board edges and install according to the manufacturer’s instructions, typically with a supporting bed of mortar. Drive the fasteners flush, spacing them according to the product's instructions. Fill the joints with mortar, and apply fiber tape to the joints prior to tiling.

Not only should tile subfloors be flat, but also strong and rigid. Joist spacing must not exceed 24 in. on center. Any give or flexibility in the subfloor can lead to cracks in the grout joints. (See side note below.)

For tile installed over a sturdy subfloor, you can also use a new polyethylene membrane that “uncouples” the thin-set mortar from the subfloor to protect against material movement.

Tile Layout

For floor tile, check the room for square. You can use the 3-4-5 Rule to check that the corners form right angles:

A. Measure and mark a point 3 feet from the corner along one wall.

B. Measure and mark a point 4 feet from the same corner on the intersecting wall.

C. Measure a diagonal line between the two points. It should measure 5 feet if the chalk lines are at 90 degrees. (In large rooms you can double the ratio; i.e., 6-8-10).

D. If the room is less than 1/8-in. out of square within 10 feet, it can usually be disguised within the layout. However, if one wall is significantly out of square, then lay out the floor so the tapered tiles will run along the least noticeable wall.

A standard procedure for floor tile layout in a rectangular room is called the quarter method, in which the room is actually divided into four quarters to help sequence the layout. First step is to measure and mark the midpoint of all four walls. Snap intersecting chalk lines at the center point of the site, forming a square cross. Start by laying a row of tiles in a dry run along each of the four lines, all the way to the walls, creating a cross of tiles in the center of the room. If necessary, use plastic spacers to keep the grout joints even. Lay tile starting from the center and work your way outward. Any cut tiles will be at the edge of the floor. Adjust the layout so that all cut tiles will be the same size on one side of the room as the other side. Keep in mind, however, that most homeowners prefer a row of full tiles at the room’s entry.

Tiles placed in a diagonal pattern can make a room appear larger. For diagonal tile layout, use the center point established with the quarter method and snap lines across the two

diagonals of the room creating an “X” on top of the cross. Then lay out the tiles along the

X as with using the quarter method. Make sure the lines are at true right angles and that the partial border tiles are equal in width.

Rectangular rooms make it easy to design the tile layout, but oddly shaped rooms or those with obstacles such as kitchen islands can be more complicated. For a visual reference, sketch a scale drawing of the living space on graph paper, including measurements, walls and any other obstacles. Tile is sold in square-foot quantities, and graphing the area can help determine the quantity needed.

Flooring professionals will remove all baseboard trim before laying the tile. However, if

floor space is not a primary concern and the baseboard has a tall enough profile, you might

be able to save time and labor by running the tile against the baseboards and concealing the joint with shoe molding. Leave an expansion gap between the tile and baseboards.

Installation Advice

Use a trowel to spread mortar over the floor where the tile will go, combing the bed to create furrows, but be careful not to press the trowel down all the way to the concrete or backer-board.

As you apply the tile to the mortar, twist it slightly and press down. Use a rubber mallet to gently tap the center of the tile to set it properly.

For tiles larger than 8-by-8 inches, back-butter the floor tiles prior to installation. "Back buttering" refers to spreading mortar onto a tile just before it is placed to ensure proper adhesive coverage. This is particularly important with natural stone tiles which tend to be more brittle. The thin layer of adhesive on the tile bonds easily with the layer troweled onto the floor to eliminate air gaps and create a strong bond.

Make sure tiles are level with one another by placing a long straight-edge across several tiles in a row. Adjust the installation to fix any discrepancies before the mortar sets.

Some tiles will need to be adjusted. It's easier to use extra mortar or adhesive to bring thinner tiles up to the level of thick tiles than the other way around. Lay thicker tiles first and adjust the thinner tiles as you go.

When working with small tile or mosaics, smoothing out the mortar ridges can help ensure proper coverage. This is especially important in wet areas like bathrooms, where voids in the mortar can trap moisture.

Wet areas should also be protected using a waterproof membrane beneath the mortar.

Installing pebble tile? The irregular shape of the pebbles can result in visible "sheet lines" when installed with the mesh backing. To avoid this, tile pros often break up the sheets or install the pebbles one at a time.

Clean up any excess mortar as you go. Use a damp sponge to wipe it up completely so it doesn't dry on the tiles. Tile adhesives are very strong, and if you try to chisel hardened mortar off the new floor, you risk chipping or breaking the tile.

When using T-shaped tile spacers, make sure to stand them upright between joints and don't lay them flat at the tile intersections, or they'll be impossible to remove once the adhesive sets.

A wet saw equipped with a diamond blade is the most versatile cutting tool for floor tile and will be available at most rental outlets.

Grout Joints

Grout joints should be sized based on the tile manufacturer’s recommendation. When using the correct grout for the application, a joint within the grout manufacturer’s recommended width tolerance should not lead to cracking.

For the cleanest grout-joint appearance with less maintenance, many professionals recommend a joint as thin as 1/8 to 3/16 inch.

Among the newest tools, the QEP LASH Tile Leveling Clips help installers level, align, space, and hold tile in place to maintain even elevation and ensure a consistent finish. The flat clips (part A of a two part system) grant even grout lines and align neighboring tile. The wedges (part B) insert through the flat clips to hold the tile at an even height. For quick and easy removal, clips are designed to break off below the surface of the tile.

Note that when installing tile in a modular pattern (using tiles of multiple sizes), consult with your tile supplier regarding the size of the grout joints. Not all tiles are made to

be installed in a modular pattern, and using tiles that are not designed for a modular

pattern will have varying grout-joint widths.

Grout should be applied after the mortar or adhesive has completely dried. The grout can be applied using a rubber float then allowed to cure overnight. On the next day, scrub the floor with a damp, abrasive sponge to remove grout residue from the floor. It’s a good idea to repeat the cleaning process for the next three days. If any grout haze remains, warm water will usually remove it, otherwise use a neutral, non-acidic tile cleaner or even a mildly alkaline detergent should work. (Note: Always follow the grout manufacturer’s recommendations for application and cleaning. Cleanup for an epoxy grout is very different from cement-based grout.)

Allow the grout to cure for a week before sealing the grout joints. Grout is usually made of a cement material, making it porous and susceptible to stains, mold and mildew if not sealed with a quality grout sealant.

Most ceramic tiles are glazed at the factory, but some types of tiles (natural stone, terra-cotta) may not be glazed and will require a protective sealer after installation. Regardless of the tile, you should always apply sealer to the grout to keep it from absorbing dirt and grime.

For more information on tile specifications, installation and design, visit the Tile Council of North America’s website at www.TCNATile.com and WhyTile.com.

SIDE NOTE 1:

How to Cut Floor Tile

A snap cutter is the easiest way to make a straight cut in tiles where they meet a wall or obstruction. Simply mark the cut line on the tile. Place the tile on the cutter’s base plate and adjust the guide bars to align the cut line with the carbide-tipped cutter. Lower the cutter onto the line and use the handle to draw the carbide wheel or blade across the tile to score the surface. Then press down on the handle to break the tile along the score line. One limitation of this tool is that it can only make cuts that extend across the entire tile, from one edge to the other. And although a tile pro might have the skills to use a snap cutter to make irregular cuts, an inexperienced user will probably be limited to making straight cuts with this tool.

Need to make small partial cuts in tile? Although they look like a pair of pliers, tile nippers provide a simple way to make small, straight incremental cuts that can remove just enough material to clear obstructions.

Another go-to tool is a powered wet saw, which is available to rent in a wide range of sizes. These tools use water to cool a circular diamond-grit blade to prolong its life when cutting such hard materials. Because it can make partial cuts in tile, a wet saw can cut out square notches.

Although the circular blade of the wet saw enables only straight cutting, you can use the saw to make rounded or irregularly shaped cuts. When you need to fit a tile against a post or molding, simply scribe the profile of the obstacle on the tile. Then, make a series of closely spaced parallel straight cuts up to the profile line.

Use tile nippers to remove the thin strips of tile between the kerfs.

SIDE NOTE 2:

A Sturdy Subfloor is Critical for Tile

Any minor amount of deflection in the subfloor can result in cracks or damage to a tiled floor. A subfloor that still has a degree of “bounce” or vibration when people walk across the room might be suitable for resilient flooring, but it’s not suitable for tile installation.

Pro remodeler Ritchie Hamilton addressed this problem at a house that had settled with sagging joists. Beneath the subfloor, Hamilton constructed a perpendicular beam with posts and piers to level the joists and stabilize the framing with additional support that connects to the ground.

The beam serves two purposes. First, it bridges across the bottom of the joists so they can all be jacked up and leveled to the same height to reduce a sag in the floor. Second, by locating the beam midway through the span of the joists, the beam essentially halves the length of the unsupported framing, which takes the flex out of the flooring. He fastened the beam to the floor joists with metal hangers, arresting movement and giving strength and stability to the subfloor, which will ensure a long-lasting tile floor installation.