With your tiled floor swept clean of mortar chips, vacuumed free of mortar dust, and wiped down with a wet sponge, you are finally ready to begin with the process of tile grouting. First up though, you must mix a quantity of grout to the correct consistency, similar to the methods of mixing floor tile mortar.
Floor tile grout comes in a wide variety of colors from popular manufacturers such as Mabei for example, but normally only comes in two different varieties depending on your application. There is un-sanded or non-sanded grout which is ideal for grouting wall tiles, or specialist floor tiles such as marble and granite which require a narrow 1/8 "inch wide grout line. is perfect for the common and popular application of ceramic floor tiling.
The only difference between the two is with the addition of tiny particles of polymer sand grains used to thicken out the mix, as with narrow grout lines the use of grain particles are less fitted tighter areas where sufficient waterproof sealing is required.
There are also as I said a wide variety of colors available to choose from, and it is usually best to pick the best grout color which accents the color of the tile design. With this being said though, do try to stay away from light grout colors. These tend to show visible stains more so darker grouts, which can be from anything such as ground-in dirt to even water residue, so choose wisely when coordinating your colors.
As with mortar, tile grout is bought as a dry powder substance to which water is added and mixed to get the correct consistency of mud. Like mortar though, there is no exact measurement or ratio of powder to water to get the correct consistency, but as a rough starting guide you can follow the rule of two cups of grout to one cup of water.
With your water already in your mixing bucket, add your tile grout and mix thoroughly. This again can be done using the drill and mixing paddle if available, but grout is normally mixed in much smaller quantities than mortar and the consistency should be less thick, therefore mixing by hand can be just as effective and not really that tiresome.
In saying that though, grout does have a tendency to require more working-in than mortar does, in order to obtain a necessary smooth and creamy consistency. The best way as always though, is to start small if you are new to the process, to get used to what it is you are trying to achieve. The correct consistency you need for floor tile grout differs from the thick molten lava or mashed potato characteristics of floor tile mortar. Grout requires a more creamy soup consistency, being able to pour out of your mixing bucket without actually being sloppy, or simply just slop out in one big lump. If it's too thick just add a little water, and if it's too thin, then add a little more grout, but keep the additions in gradual and small doses.
To mix the grout by hand, you can use an epoxy grouting float, which is actually the ideal tool for spreading tile grout also. There are other float tools available for spreading, but I personally find the epoxy float to be the best method of giving a solid and even spread compared to some of the sponge floats available. Having used many of these methods in the past, I certainly would not go back to them since having experienced the solid epoxy float. It may be a little on the pricey side compared to the others, but if looked after it will last you a lifetime as opposed to sponge based grouting floats.
Once you have your grout mixed to the correct consistency, before laying and spreading into your grout lines always allow it to have a settling period between mixes to ensure a good chemical bonding, just as with floor tile mortar. First mix the grout for approximately 5 to 10 minutes, then let it sit for approximately 5 to 10 minutes, and then give it one final mix for 2 minutes before actually applying it to the tiled floor.