Tile grout is the hard, cementitious material that fills the joints between ceramic tiles. It was once standard practice for tile grout to be white, but today's decorating styles often call for colored grout that complements or contrasts with the field tiles.
If the existing grout on your tile installation has become dirty or discolored due to mold or mildew—or if you just want a new look—there are two ways you can change the color without tearing out the entire tile job and starting over. Grout lines can be changed by tinting them with a colorant, or the grout can be ground out entirely and replaced with fresh grout that has the color you want.
Before You Begin
Recoloring Existing Grout
Recoloring tile joints is an appropriate method only for traditional glazed ceramic or porcelain tiles. It will not work for natural stone tiles that are unsealed, as the colorant will almost always stain the tiles.
Tile colorants come in many styles, and you may have to try several to find one that works best. Some do not work very well on epoxy grouts, for example, while others may be best suited only for grout that has not yet been sealed. Many of today's colorants, however, are a mixture of colored pigments and sealers that are formulated to work well on almost any existing grout.
Some grout colorants come as simple "pens" that allow you to paint over the grout lines with colorant. There is no harm in trying these, but better results are usually obtained with colorant the is brushed into the grout lines. The excess colorant is then wiped off the tiles.
When changing the color of existing grout, you usually get the best results when changing to a darker color. Changing to a lighter color often requires multiple applications.
In most cases, the better, more long-lasting solution is to remove the grout and replace it with new grout that has been tinted the color you want. In smaller areas, such as backsplashes and tub/shower surrounds, this project can be less difficult than you may fear. If the grout is crumbling or otherwise physically in poor shape, it may come out rather easily, and the new grout, if properly sealed, will keep the cement board and studs behind the tile dry and in good shape.
On large surfaces such as a kitchen or bathroom floor, however, grinding out existing grout can be fairly laborious, especially if the floor is covered with small tiles with many, many grout lines. Before tackling the removal of all the grout, you may want to first test recoloring to see if this provides acceptable results.
Click Play to Learn How to Change the Color of Your Grout
Equipment / Tools
Coloring Existing Grout
- Small scrub brush
- Colorant brush (or toothbrush)
- Grout saw or multi-tool with grout blade
- Breathing protection
- Eye protection
- Small flat-head screwdriver
- Utility knife
- Shop vacuum
- Stiff scrub brush
- Mixing bucket
- Mixing trowel
- Grout float
- Grout sponge
- Foam paintbrush
Coloring Existing Grout
- Grout cleanser
- Grout colorant
- Painter's tape (optional)
- Plastic sheeting or drop cloths
- Grout pigment
- Microfiber cloths
- Grout sealer
How to Change Grout With Colorant
At one time, it was quite hard to change the color of grout that had already been sealed, but today's colorant products do a very good job of changing the color of grout lines on any type of grout, even if it has already been sealed. The key is to first use a good commercial grout cleaner to thoroughly scrub the grout joints.
Modern grout colorants are usually a blend of colorant and sealer, and application is a matter of simply painting the material onto the cleaned grout lines with a stiff brush.
Scrub the Grout Lines
Use a commercial grout cleaner to thoroughly scrub the grout lines with a small stiff scrub brush. After scrubbing, rinse and neutralize the cleaner with clear water wiped over the tiles with a sponge.
The colorant product usually recommends a specific grout cleaner for this preparation step. It's best to follow this recommendation, as the products have been tested to be compatible with one another. You may also have good luck using ordinary white vinegar, followed by a paste made from a mixture of water and baking soda, as a cleanser for dirty grout lines.
Test the Colorant
Find an inconspicuous spot on the tiled surface to test the colorant. Apply the colorant to a few inches of grout, then let dry as directed by the manufacturer. Make sure the colorant dries to a penetrating hard finish and that it bears up under light scrubbing without flaking off. If it does not perform well, you may want to try another type of colorant—a staffer at a tile outlet center may be able to advise you.
Clean and Rinse the Tile and Grout
Using a sponge and water, clean and rinse the tile and grout thoroughly. Let the tile and grout dry overnight before moving on to coloring.
Mask Off the Tile Surfaces (Optional)
Tape off the tile faces with painter's tape, if desired, leaving only the grout lines exposed. This is an optional step but is recommended by some tile professionals. Taping off is the best way to prevent staining on the face of unsealed tiles. It's best to work in small sections, taping off a few square feet and coloring it before moving on to the next section.
Apply grout colorant with small stiff brush or a pen loaded with grout dye, following the manufacturer's directions. Work the colorant forcefully into the grout, trying to avoid getting too much colorant onto the face of the tiles. A toothbrush is a good tool to use for applying the colorant.
Wipe Off Excess Colorant
While the colorant is still wet, wipe off any colorant that gets onto the faces of the tiles. 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.
Seal, if Necessary
Let the grout dry completely, as directed by the colorant manufacturer. Many colorant products are now pre-blended with sealer, requiring no further sealing after application. Others are pure dyes that must be top-coated with sealer after they dry.
If directed by the manufacturer, brush on a sealer over the colorant after it dries completely. Sealing the grout lines prevents future discoloration. It is normal for the sealer to make the grout lines shiny and slightly darker.
How to Remove and Replace Grout
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 or wider. Epoxy grouts consist of an epoxy resin that is activated by a catalyst/hardener; they are appropriate for applications such as steam showers or shower floors.
Remove Old Grout
Cover floors and furniture with plastic sheeting or drop cloths to protect surfaces.
Remove the old grout using an appropriate tool, such as a manual grout saw or a multi-tool fitted with a tile blade. This can be a messy, painstaking job that creates a lot of dust, so make sure to wear breathing protection and eye protection.
Use a small flat-blade screwdriver and a utility knife to clean up the tile edges and get into tight spaces.
Inspect the Tiles
Check to make sure that the tiles are securely attached to the substrate. Tap on the tiles with the plastic backside of a screwdriver. A hollow sound usually means that the attachment is weak and that the tile should be removed and replaced. Loose tiles are often indicated when grout lines are especially crumbly and easy to remove—just replacing the grout will not fix the problem.
Remove Grout Particles
Remove the grout particles from between the tiles, using a shop vacuum with a flat nozzle attachment. Scrub the grout lines with a stiff brush as you move the vacuum nozzle, which will dislodge loose particles.
Add Pigment to Grout Mix
Add colorant 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.
Make sure to blend the colorant and grout very thoroughly, so the color is uniform throughout.
Apply the Grout
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. Tools required include a grout float, a grout sponge, and microfiber cloths for cleaning haze off the face of the tiles.
Allow the grout to fully dry and cure before moving on to sealing. This may be as long as three days for some grouts—follow the manufacturer's recommendations.
Seal the grout after it has fully cured, if recommended by the grout manufacturer. The sealer helps protect the grout from stains and discoloration. Be aware that sealant slightly darkens grout and gives it a shiny appearance.
Allow the sealer to dry overnight before allowing tile to get wet.
When to Call a Professional
While regrouting tile is not complicated, it is a tedious, exacting job that requires a great deal of patience. If you feel that you cannot do an adequate job, tile installers generally will agree to take on regrout projects.