Cracking and crumbling grout falling from your tiles is frequently a sign of a badly mixed or installed grout. When this happens, water can seep between the tiles, cause harm to the wall supporting the tiles or loosen the tiles, causing them to fall in the wall. You must remove the old grout before you replace it with fresh grout. Be sure to use the correct grout for your tile application, such as unsanded grout with latex additive for bathroom tile or sanded grout for floor tile using joints wider than 1/8 inch.
Eliminate old grout from between the tiles using a grout saw, an oscillating tool using a carbide cutter blade along with a rotary tool with a carbide grout removal bit. A grout saw takes you to transfer the saw back and forth manually to remove the grout, even though a rotary or oscillating tool takes less effort.
Clean the distance left between the tiles with water and an old toothbrush. Wash the area well with fresh, clean water and enable the tile to dry for 24 hours.
Pour powdered grout to your bucket. Add a small amount of water and then mix the grout using a margin trowel. Continue to add small amounts of water until the grout reaches the consistency of peanut butter.
Allow the grout to sit undisturbed for about 10 minutes. Use the margin trowel to remix the esophagus. Do not add water.
Scoop some grout in the bucket using a rubber grout float. Hold the float at a 45-degree angle from the tile and then sweep the float diagonally across the tile, pushing the esophagus to the grout lines.
Eliminate the excess grout from the surface of the tiles using a clean grout float. Hold the float at a 90-degree angle from the tile. Sweep the grout float across the seams diagonally, choosing the excess grout.
Consider five minutes to get the grout to dry. Press your thumbnail to the esophagus; when it leaves an indentation, wait another five minutes and check the grout with your thumbnail once again. Wait until your thumbnail does not leave a feeling before cleaning the tile.
Clean the tile surface using a water-dampened grout sponge. Use short strokes to eliminate any remaining irritation, rinsing the sponge frequently with clean water.
Wipe the tile surface with a moist soft cloth to remove any grout haze. Buff the tiles using a soft dry cloth immediately after removing the haze.
Fill a general-purpose spray bottle with clean water. Mist the new grout a couple of times a day for three days.
Apply grout sealer having a artist paintbrush. Wash any sealer from the surface of the tile immediately. Let the grout dry for at least 24 hours.