Tile just keeps getting bigger and bigger—in popularity and in size. The materials have changed too: Ceramic is still around, but porcelain and glass are now almost as common. Our tile guru, Dean, has had to change how he works. Here are some of his tile installation tips.
Pick a large-notched trowel for big tile
Big notches require more thin-set
Tiles as large as 2 ft. square have become more popular, and these monsters require a deep layer of thin-set to allow for adjustments. To get the right amount of thin-set, use a 1/2 x 1/2-in. notched trowel for tiles up to 16 in. square, and a 3/4 x 3/4-in. notched trowel for larger tiles. Don't forget: Using large notched trowels means you'll need a lot more thin-set. As a general rule, a 50-lb. bag of thin-set will cover about 40 to 50 sq. ft. using a 1/2 x 1/2-in. notched trowel, and about 30 to 40 sq. ft. using a 3/4 x 3/4-in. notched trowel. When you use large notched trowels like this, look for thin-set labeled “medium bed,” “large tile” or “large format.”
Cut without cracking the tile
Diamond wet saw technique
You'll need a diamond wet saw to cut large porcelain tiles. Dean recommends renting a contractor-quality saw rather than buying a cheapie. But even with a saw like this, tiles larger than about 8 in. square have a tendency to crack before you finish the cut, often ruining the tile. You can help prevent this by pressing the two pieces together as you near completion of the cut. Holding the tile like this stabilizes it and dampens vibration, resulting in a cleaner cut.
Upgrade your grout sponge
Removing grout haze
It's hard to get the last bit of grout haze off using a grout sponge. After the grout dries, you usually have to come back and polish off the remaining cloudy layer with a rag. But if you finish your grout cleanup with a microfiber sponge, you'll end up with a job so clean you may not have to do anything more.
Start your cleanup with the plain side of the sponge after the grout firms up. If you need more information on this process, check out these grouting tips and techniques. Then when the joints are nicely shaped and most of the grout is off the face of the tile, switch to the microfiber side of the sponge.
Flatten the framing
Straighten the walls before installing backer board
Old-school tile setters made up for wavy walls by installing wire lath and floating a layer of mortar over it. But modern tile backer boards simply follow along the crooked wall, and if you don't fix the wall, you'll have a wavy tile job.
The best solution is to straighten the walls before you install the backer board. Lay a straightedge against the walls to find high and low spots. In most cases, you can fix problems by adding shims to the face of the studs until the faces all line up. But if you have just one protruding stud, then it may be quicker to plane it down with a power planer or replace it if you can.
Dean prefers thin paper shims as shown (available in the drywall section of some home centers) because they provide precise control over shim thickness and can be offset to create a tapered shim. You can make your own thin shims from heavy felt paper or thin cardboard. Staple the shims in place.
Back-butter large tile
Butter the back to ensure a strong bond
The increased surface area of tiles larger than about 8 x 8 in. makes it critical that you butter the back to ensure a strong bond. It takes only a few extra seconds per tile to spread a thin layer of thin-set on the back of the tile with the flat side of the trowel. Then when you set the tile, this thin layer bonds easily with the layer you’ve troweled onto the floor or wall and creates a strong connection.
Dean also butters the back of larger transparent glass tiles to provide a consistent color. Otherwise you’ll see air bubbles and other imperfections in the thin-set through the transparent glass.
Flatten thin-set before installing mosaic tile
Avoid mortar squeezing out between tiles
Mosaic tile is typically thin, and it has a lot of grout joints. If you simply apply thin-set with a notched trowel and embed the sheets of mosaic in it, the ridges of thin-set will squeeze out of all those grout joints and you'll have a real mess to clean up.
The way to avoid this is to flatten the ridges with the flat side of the trowel before you set the mosaic tiles in it. Use the notched side of a 1/4 x 1/4-in. V-notched trowel first to apply the right amount of thin-set. Then flip the trowel over to the flat side and, holding the trowel fairly flat to the surface and using medium pressure, flatten the ridges. Now you can safely embed the sheets of mosaic tile without worrying about thin-set filling the grout joints.
Clean grout joints with a toothbrush
Remove excess thin-set
No matter how careful you are, you're bound to end up with some thin-set in the joints between tiles. And if you allow it to harden, it'll interfere with your grout job. A toothbrush works great to clean excess thin-set from grout joints, especially for the skinny joints between mosaic tiles. Let the thin-set get firm, but not hard, before you start the cleanup process. If you try to clean up thin-set too soon, you risk disturbing the tiles.
Make a custom trowel
Dean has discovered that inexpensive auto-body filler spatulas, available at home centers and auto parts stores, are perfect for making custom trowels for special circumstances. One way Dean uses a custom-made trowel is for insetting thinner tiles into a field of thicker tiles. After finishing the field tile installation, he cuts notches on each edge of the spatula with a utility knife to create a mini screed. He cuts the notches about 1/16 in. deeper than the thickness of the decorative tile to allow for thin-set. Then he uses this trowel to add a layer of thin-set that acts as a shim when it hardens. After this layer hardens, he cuts 3/16-in.-deep teeth in the spatula to make a notched trowel and uses it to apply thin-set. Now when he sets the decorative tile, it's perfectly flush with the field tile.
Finish your job with premium grout
Premium grouts give better results
There's been a revolution in grout technology over the past several years, and all of the big-name grout producers have modern grout that's easier to apply, denser, more stain resistant and more colorfast than standard grout. These new grouts also cure faster and are resistant to mold and mildew.
You no longer have to mix in latex additives, worry about uneven or blotchy grout joints or decide between sanded and unsanded grout. Power Grout, Custom Building Product's Prism and Fusion Pro grouts, and Laticrete's PermaColor are a few examples of premium grout. You may have to visit a specialty tile store to find them, though. The formulas vary, but all of these will outperform standard grout. And some, like Power Grout and Fusion Pro, don't even require sealing, saving you time and money.
Premium grouts are more expensive, of course, and will add to the total cost of your project. But considering all the other costs (and all your hard work), premium grout is a bargain.
Level mosaic tile with a block
Apply even pressure with your fist
Mosaic tiles are so small and numerous that getting their faces flush using just your fingers is nearly impossible. But tamping them with a flat block of wood creates a perfectly aligned surface in no time. Make a tamping block out of any flat scrap of wood. An 8-in. length of hardwood 1x6 or a 6 x 8-in. rectangle of plywood is perfect. After you set several square feet of mosaic tile, pat the tile into the thin-set with the tamping block. Hold the block in place and bump it with your fist to flatten the mosaic. Repeat the tamping process on each new section of tile you install.