Grouting is the final step of installing ceramic wall tile after the tile adhesive has fully cured. Grouting is not difficult to do well, but it is even easier to do poorly. One key to success is to remember that grout has a limited working time and can dry before you know it. If you grout an area that's too large, the grout will set up and become difficult to work with or remove. The trick is to work in small areas of 5 to 10 square feet or less so you'll have enough time to complete the required steps before moving to the next section.
Grout comes in premixed and powdered forms and in sanded or non-sanded types. Powdered grout must be mixed with water before use. Premixed grout comes in tubs and is convenient for small jobs. A non-sanded grout is suitable for grout joints up to 1/8 inch wide. Sanded grout is best for joints over 1/8 inch wide. Sanded grout is a little more difficult to work with than non-sanded, but it's stronger and helps prevent cracking in wide joints.
Equipment / Tools
- Needlenose pliers
- Margin trowel or putty knife
- 1-gallon plastic bucket
- Rubber grout float
- Grout sponge
- Grout joint tool (optional)
- Cloth or microfiber towel
- Mr. Clean Magic Eraser® or cheesecloth
- Painter's tape
- Rosin paper or plastic sheeting (as needed)
- Tile sealer and applicator (as needed)
Protect Adjacent Surfaces
Begin by protecting adjacent surfaces from spilled grout, using painter's tape and rosin paper or plastic sheeting. Cover horizontal surfaces with paper or plastic, securing it in place with painter's tape. Apply tape along adjacent walls and cabinets where they adjoin the tile surfaces.
Prepare for Grouting
Prepare the tiles before mixing the grout. Remove any tile spacers left from the tile installation, using needlenose pliers. Clean the joints of any loose materials or adhesive that might interfere with the grout's ability to seal against the tile. Make sure the face of the tile is free of adhesive and other contaminants.
If you are grouting porous tile or stone, pre-seal the tile with an appropriate sealer to prevent the grout from staining the tile. Before grouting porous tiles, lightly dampen the surface of the tiles with clean water to help prevent the grout from sticking to the tile surfaces.
Mix the Grout
To prepare premixed grout: Stir the grout in the tub, using a small margin trowel or a putty knife. The mix should be fully blended and have a smooth, toothpaste-like consistency.
To mix powdered grout:
- Mix the grout powder with water in a plastic bucket, using a margin trowel and following the manufacturer's directions. Add water very slowly until it reaches a toothpaste-like consistency. Be careful not to add too much water—if the grout becomes soupy you will have to add more grout powder to regain the correct consistency. Once the grout reaches the toothpaste-like consistency, stop mixing!
- Let the grout set for about 10 minutes, allowing it to fully absorb the water. This process is called "slaking."
- Remix the grout. Carefully add more water, if needed, to achieve the desired toothpaste-like consistency.
Apply the Grout
Apply the grout with a rubber grout float, filling the joints over a 5- to 10-square-foot area. Begin by scooping up a load of grout onto the grout float, using one end of the float. Do not cover the entire float with grout. Next, apply the grout to the tile, working from the bottom of the section upwards, and holding the float at an angle of about 45 degrees. Sweep diagonally across the tile, forcing the grout into the joints. Reload the float and continue to apply the grout to complete the first section.
Make a second pass with the float, holding it at a steeper 70- to 90-degree angle (almost perpendicular) to the wall and scrape off any grout residue from the faces of the tiles. Periodically rinse the float in the bucket of warm water. Empty and refill the bucket with clean water as needed.
You may find it easier to first work the grout fully into the joints by moving the float parallel to the joints, then reloading the float and working in a diagonal direction across the faces of the tiles.
Sponge the Tile and Grout Joints
Wait about 20 minutes before cleaning off the grout residue with a grout sponge (do not use a standard kitchen sponge, which has sharp edges and corners that pulls the grout out of the joints). Dunk the sponge into a bucket of clean, hot water, then wring it out until it is almost dry. Wipe across the tiles in a diagonal direction with a clean face or edge of the sponge. Rotate the sponge to a clean side after each pass. Rinse the sponge in the water, and wring it out. Repeat the process to clean the entire first section of grouted tiles.
Make sure the sponge is not too damp. If the sponge has water running down the face of the tile, it is too wet! As you work, the sponge will pick up some grout from the joints and across the face of the tile, leaving a slight haze. This is normal; the haze will be removed later.
Tool the Grout Joints
Tool the grout joints, as needed, using your finger or a grout joint tool. The goal is to shape the joints to a consistent concave shape and depth, smoothing out irregularities. Use your index finger for joints up to 3/16 inch wide; use a grout joint tool for larger joints. Move your finger (or the tool) firmly across the vertical and horizontal joints, removing excess grout as you go.
Clean the Tile with a Cloth
Allow the grout to set up for about 1 hour or until it is firm. Clean the haze from the tile surfaces, using a clean rag or a microfiber cloth that is very slightly dampened with water. Wipe off the residual haze, rinsing the cloth frequently in clean, warm water. Lightly clean the tooled joints and any exposed grout lines along the edges of the tile installation.
Buff the Tile
Clean the tile again after the grout has hardened completely. You can use clean cheesecloth, but a Mr. Clean Magic Eraser ® is more effective. Buff the tile to a bright shine.