Tile grout doesn't last forever. Long before it begins to physically deteriorate, tile grout will become discolored and unattractive. While this is an inevitable part of having tile flooring, walls, backsplashes, or counters, few homeowners ever want this or want to deal with it. Grout discoloration happens because of mold and mildew, as well as dirt that imperceptibly collects in the grout joints over time. No matter how religiously you seal the grout and no matter how much you scrub the grout, you are bound to end up with dingy, discolored grout.
Another reason you might want to change the color of grout is that you simply don't like the original color. Whatever your motivation, it is possible to change grout color in two ways. You can either remove and replace the grout with new grout of a different color, or you can apply a colorant to your existing grout.
Changing Grout Color by Replacing It
The most thorough and complete solution is to remove the grout and install new, grout in the color of your choice. In small areas, such as backsplashes and tub or shower surrounds, this project can be less difficult than you might imagine. If the grout is crumbling or otherwise physically in poor shape, you gain the added benefit of all-new grout that keeps the cement board and studs behind the tile dry and in good shape.
- Remove the old grout with an electric multi-tool fitted with a tile blade or a manual grout saw. Use a small flat-blade screwdriver and a utility knife to clean up the tile edges and get into tight spaces.
- Remove the grout particles from between the tiles, using a shop vacuum with a flat nozzle attachment.
- Choose a new grout that is suitable for the tile installation. As a general rule, unsanded grout is used for grout joints under 1/8 inch wide, while sanded grout is used for joints 1/8 inch wide and wider.
- Add pigment to the grout mix, if desired. Grout comes in a fairly broad range of factory-mixed colors, but you can create a custom color with powdered grout pigment or liquid grout dye.
- Mix and apply the grout, following the manufacturer's directions. Grouting is a three-step process of filling the joints, removing the excess, and cleaning the tile faces.
- Seal the grout, if desired, after it has fully cured. Sealer helps protect grout from stains and discoloration, but it can prevent you from changing the grout's color in the future. Be aware that sealant slightly darkens grout and gives it a shiny appearance.
Changing Existing Grout Color With a Colorant
Most homeowners would like to avoid removing grout if at all possible. One way to bypass the work and mess of removal is to preserve the grout but change its color. Grout can be colored with dyes after it has been installed and this is a good choice if the grout is stable and solid. Keep in mind that with existing grout, you can change the color only to a darker color; you can't make dark grout lighter.
- Inspect the grout to make sure it is suitable for coloring. Grout colorants require porous grout (to accept the colorant) and glazed tile surfaces (to prevent staining the tile). If the grout has intact sealer, it will not be porous enough to accept colorant. Any grout that easily sheds water is not appropriate for grout coloring.
- Clean and rinse the tile and grout thoroughly, and let it dry completely.
- Tape off the tile with painter's tape, if desired. This is an optional step but is recommended by many tile professionals. Taping off the tile is the best way to prevent staining. Be aware that you can tape off and work on only a limited section of tile at one time.
- Apply grout colorant with a special grout brush or a pen loaded with grout dye, following the manufacturer's directions. Work in small sections at a time.
- Wipe off any colorant that gets onto the tile faces as soon as recommended. Some products can be scrubbed off of tile as long as two hours later with a nylon-faced sponge, provided the tile is well-glazed. Follow the manufacturer's instructions carefully.
- Let the grout dry completely. Add a grout sealant, if desired. Again, sealer will make the grout look darker and shiny.