Choosing, mixing, applying and sealing the messy stuff that goes between tiles.
Synopsis: After new tile goes down on the floor or in the shower, gaps between the tiles must be filled with grout. The author explains the process, with tips on the right tools and advice on what kind of grout is best.
If there’s one thing that most tile installers dislike, it’s grouting. A monotonous, shoulder-wrenching task, grouting is often delegated to the low man on the totem pole. That’s a big mistake. Nothing can ruin a top-notch tile installation quicker than a bad grout job. An inexperienced helper can leave shaded or splotchy grout, uneven joints or grout that can be scratched out of a joint with the stroke of a fingernail.
Years ago, white-wall grout was nothing more than Portland cement mixed with water; floor grout was mixed on the job by combining fine white sand with cement in a 1:1 ratio. Latex or polymer additives weren’t an option, so installers simply added water to the mix. It worked—tile that was installed 50 or more years ago remains intact in many homes—but it had its limitations. Color choices were usually limited to white, black or gray. These days, grout is available in a rainbow of colors.
Modern grout products are also stronger and easier to use. The only factors that need concern tile installers are the type of grout to use, the proper consistency of the mix, even application and a thorough cleaning. And they shouldn’t forget additives and sealants.
The width of the joint determines the type of grout
There are two basic types of grout: sanded and unsanded. Which type of grout that you use is usually determined by the width of the joint between the tiles. Unsanded grout is the product of choice for any tile installation where the joints are less than 1/8- in. wide, even on floor tile. The finish is smooth, and it is relatively easy to clean.
Primarily used in joints wider than 1/8-in., sanded grout (also called floor grout or joint filler) provides the necessary strength for joints up to 1/2-in. and even wider. Although you might get away with unsanded grout in joints slightly wider than 1/8- in., it’s a poor bet. More than likely, tiny hairline cracks will form as a result of shrinkage, which is controlled by sand in the mixture.
As you might guess, the texture of sanded grout is rougher and a bit harder to clean. Although sanded grout is associated primarily with floor tile, it should be used on any tile with wider joints, no matter where it’s installed. However, be prepared for a long day if you plan to grout a wall with sanded grout. Unsanded grout readily clings to vertical surfaces, but sanded grout tends to roll down the wall and end up in little piles on the floor. It’s possible to use sanded grout in thin joints, too, but pushing the thicker mixture into tight grout joints can be a frustrating task that typically leaves small pinholes in the grout finish.
Unlike products of ten years ago, most grouts on the market now include a latex or polymer additive that strengthens the grout and helps it to resist staining. Although you can buy grout without admixes, I don’t bother; I’d rather have the extra protection that admixes offer.
For more photos and details on grouting tile, click the View PDF button below.