Remove spacers and prepare grout
Once all tiles are installed and the mortar is set, remove all spacers and calculate the amount of grout you will need. You can find calculation instructions on the grout packaging. Use painter’s tape to cover any baseboards, trim, and other nearby flooring that might come into contact with the grout.
Mix the grout
Not all grout requires mixing before it’s ready to use, and the composition of your grout will depend on tile joint thickness and how you want to use your space. If your grout does need to be mixed, combine the components in a large bucket with a paint stirrer stick or a margin trowel.
Just like with mortar, let the mixture set for ten minutes, or as recommended by the manufacturer. Don’t mix too much at one time, or it could be dried out before you have a chance to use it.
Apply the grout
Using a grout float, smooth the grout into the gaps between your tiles with sweeping motions. The grout float should be held at a 45 degree angle, and should be applied diagonally to keep the grout level consistent between tiles. Make sure joints are completely filled by the grout. Remove as much excess grout as you can during application.
Clean grout lines
Setting time for grout will vary by composition and type, but you can get a good estimate from the manufacturer’s instructions. Before the grout has a chance to set, wipe down the tile surface with a damp – but not wet – sponge. Excessive water before setting can ruin the grout. Any remaining grout on the tile surface can be removed with a grout haze solution.
Seal the grout
Depending on the type, it can take up to a few days for grout to completely cure, so avoid walking over the tile during this time. Once the grout is completely cured, apply a seal to waterproof the grout and make it easier to clean.
Application methods will depend on the product you choose, but be sure to remove any excess sealer before it has a chance to dry on the surface of the tile. You will need to reseal the grout after a year or two. If you see drops of water absorbing into the grout lines, then you know it’s time to apply sealer again.