Once the tiles are all set level and cured, its time to start applying grout. Before you can apply grout you need to remove any plastic spacers that were used to keep the tile spacing even. Plastic spacers can be picked out using a pick, screwdriver, or needle nose pliers. As a part of the spacer removal, some loose bits of mortar may break apart and fall into the grooves between the tiles. For a successful grout application all of the loose material needs to be taken out. There’s really only one tool that does an effective job of removing loose debris from between tiles, and thats a vacuum cleaner. Any type of manual removal tool such as a brush will only create more as it rubs.

When purchasing grout you should know there are a few basic differences in the grout types. There are expoxy based grouts and there are cement based grouts. Typically epoxy grouts are more expensive because they are less prone to staining and mold growth. Unless you are on a tight budget or the epoxy is substantially more expensive, the epoxy base is a better choice. When looking at cement based grouts there are sanded and unsanded grout. The sand in sanded grout is a filler to make the grout less expensive. For soft tiles like some marble types you probably don’t want to use sanded grout as the sand will scratch the tile in the process of application.

As a part of your plan you should choose a grout color or grout coloring system that fits your design. If you want to draw attention to the gridlines in the floor pick a grout color that contrasts the color of the tile. If you want the lines to be less noticeable find a grout color that matches the tile color as closely as possible.

Once you’ve mixed up your grout you will likely want to use a spray bottle to lightly mist over the tiles in the area you are working before running the grout over the tiles. When you are finished there will be a haze left on the tiles from the grout application and if the tiles are misted lightly the haze will clean off much easier. Follow the grout manufacturers specifications closely here as timing for applying the grout, wiping it off, and how much water to apply are all semi critical. If you wipe away the grout haze too soon it will pull the grout back out of the gaps. If you wait too long the haze will be near impossible to remove. You may also need to keep the grout misted for a few days after the tile is grouted while it drys. That keeps the surface of the grout from cracking while the grout further down in the channels drys. Exactly how long to keep the surface damp if at all will be in the grout manufacturers directions so be sure to read them carefully.

For the actual application of the grout use a grout float. A grout float is a tool similar to a trowel except the bottom of it has a sponge on it. To use a grout float, you run the tool at an angle against the tile pushing the grout down into the gaps. You should go diagonally across the tile as opposed to straight across so the edge of the grout float doesn’t dip down into the gaps as you move across. Cover the entire tile surface with grout forcing it down into the gaps between tiles as you go.

After the grout is applied you have to wait a set amount of time for it to setup then go back with the grout float and wipe off the excess. The time to wait is again specified by the grout manufacturer. To remove the excess dip the grout float in a bucket of fresh water, hold the float almost on its side and wipe across the surface of the tile. Keep dipping and wiping the tile to remove as much of the haze from the tile surface as possible. Be careful not to pull up the grout from the lines between the tiles, and work quickly. The longer the haze remains on the tile the harder it will be to remove. After you’ve completed the job with the grout float, you will probably have to go back over each tile and buff out any remaining haze using a wet paper towel.

Once the haze is scrubbed off all that is left is to wait for it to cure typically 48 hours, then proceed to the step in the next article, Sealing your grout and tiles.