How to Grout a Tile Floor
Durable and stain-resistant, tile is a highly useful material for flooring. Grouting tile helps to hold floor tiles together, and grout prevents debris from collecting in the joints between tiles and makes cleaning easier. Yet grout is more than just functional. With hundreds of colors to choose from, grout is an important style element in the overall tile design.
Type of Tile Grout to Use
Sanded vs. Unsanded Tile Grout
Sanded tile grout contains sand and other fine materials that contribute to strength. For grout joints that are between 1/8- and 1/2-inch wide, use sanded grout.
Unsanded grout is best for joints less than 1/8-inch wide. Because unsanded grout is smooth and contains no abrasives, it is best for glossy honed tile or stone because it will not scratch the surface.
Dry vs. Premixed Grout Mix
Using dry tile grout and mixing it with water is a great way to save money over using premixed grout. But if you're having a hard time achieving the right consistency and blending out the dry lumps, buy tubs of premixed tile grout.
When to Grout a Tile Floor
Thinset mortar takes 24 hours to fully dry before grouting. For tile adhesives, wait 48 hours.
Apply grout only when the temperature is within the range specified by the manufacturer, generally between 50°F and 100°F. Because this is an indoor project, weather should not affect when you grout the floor.
Wear latex or latex-substitute gloves when handling tile grout. Wear breathing protection when pouring out and mixing dry grout.
Kneeling on tile is hard on the knees, so use knee pads or a folded-up towel.
Wiping down the tile to remove grout and grout haze creates a slippery surface. Avoid walking across recently grouted tile as much as possible.
What You'll Need
Equipment / Tools
- Margin trowel
- Rubber tile float
- 2 buckets
- Knee pads
- Tiling sponge
- Microfiber towel
- Shop vacuum
- Old screwdriver
- Power drill
- Drill mixer attachment
- Sanded or unsanded tile grout
- Grout additive
- Grout haze cleaner
Clean Tile Joints
Use the shop vacuum to clean out debris from the open tile joints. If any dry thinset mortar extends into the joints, carefully chip it away with an old screwdriver or a grout scraping tool.
Dry grout: Pour out a small amount into a clean bucket. Slowly add the amount of water specified in the product instructions. Add grout additive, if desired.
Chuck the mixer attachment into the power drill. Turn the drill on low speed and mix the grout until it has a smooth, peanut butter-like consistency.
Premixed grout: Stir the grout with the margin trowel to mix in any water that may have risen to the top. Do not add grout additive to premixed grout.
Dampen Porous Tile
When working with porous tile, lightly dampen the tile by misting with cool, clean water.
Add Grout to Tile
Pick up grout from the bucket and drop it on the tile. Begin with just a small amount.
Spread Grout Diagonally
Holding the rubber tile float on-edge at a 45 degree to the tile, spread the grout across the face of the tile, forcing the grout into the joints. Spread the grout diagonally across multiple tiles within a 5 to 10 square foot area. When you select your float, make sure it's appropriately sized for the tile you're installing.
Smooth out Grout Along Joints
Run the narrow end of the rubber tile across the top and in line with joints, stopping before you reach intersecting joints.
Clear Excess Grout
Dampen the tile sponge in clean, cool water. Wipe off excess grout from the tile faces. Be careful not to dig out grout from the joints.
Clean off Grout Haze
After the grout has hardened, mix grout haze cleaner in clean water. Wipe down the tile with a tile sponge until the tile is clean.
Tips and Techniques for Perfect Tile Grout
Add Color to Grout
Home centers and hardware stores tend to stock a limited number of pre-tinted grouts. Colors range from white to black at the two extremes, with a palette of mostly beige and earthen colors in-between.
For more vibrant or unusual colors, you can special order pre-tinted grouts from suppliers. Or add your own liquid color acrylic to white grout for an infinite number of choices.
Fix Small Joint Depressions
Have a little grout saved off to the side to manually fill in unexpected depressions in the joints. Ball up mortar to the size of a marble, then press it into the depression with the heel of your hand. Rub your hand over the area to smooth it out.
Avoid Digging out Grout
Overworking grout joints leads to grout dig-out, where edges of the tile float extend into the joint and pull up the grout.
Pressing too hard, using the corners of the float, or simply running the float across the tile surface too many times can result in grout dig-out.
When to Call a Professional
Due to the patience and care required to grout a tile floor, beginner or intermediate do-it-yourselfers may want to confine themselves to grouting smaller floors. Call a tile company for larger tile floors or for complicated tile designs.