Grouting a ceramic tile floor is a messy job. After you have completely filled the grout joints, there will be a lot of excess grout on the top of the tiles. Cleaning this excess grout early in the process will save you from the backbreaking work of cleaning off dried grout.
Tilt the rubber grout float to a 45-degree angle. Swipe the float across the floor at this angle. Always work diagonally across the tiles as you remove excess grout. Place the excess grout back into the bucket of mixed grout.
Wait for the grout to harden for approximately 20 to 30 minutes. This allows the grout to slightly cure before you wipe it with the grout sponge.
Fill a bucket with water. Place the grout sponge into the water and then ring out the sponge until it is just slightly moist. You do not want to introduce a lot of extra water into the grout at this stage of curing or it could weaken it.
Wipe the top of the tiles with the grout sponge. Again, be careful that you do not remove the grout from the tile joints as you remove it from the top of the tiles. Rinse out the sponge into the bucket of water frequently.
Wait for the grout to harden completely, approximately 24 hours. When the grout has hardened there will still be a slight haze from the grout on the top of the tiles. Use a dry cloth to "buff" the top of the tiles and remove the grout haze.