Tips on How to Grout Tile
By Brian Nelson

Welcome to the Construction Corner. We’d like to give you a little information on working with grout. On occasion we have seen that tile grout can break loose or could wear away by traffic and grease. So here are a few hands on tips for applying and wiping grout on tile.

Clean the surface:

Before you mix grout, you need to clean the tile surfaces and grout joints to remove excess thin-set or any other unwanted debris. Vacuuming the area is recommended.
Wet the sponge and wring it out as dry as you can. Excess water in the sponge will leave too much water in the joint, which will cause problems later.
If tile has been replaced wipe the joints to remove most of the excess thin-set. Keep rinsing the sponge frequently. For larger remaining clumps after the first wipe gently scrape with a stiff putty knife on the surface of the tiles.
If you’ve done a good job of wiping excess thin-set during the setting phase, this cleaning job should go quickly. The whole idea is to have fairly clean joints to hold the grout. Excess thin-set in the joint will become visible when you wipe the grout.

Mixing the grout:

For most jobs, hand mixing is adequate. Only for large jobs with more than one worker would you need to mix a large amount of grout with a mixer. I like to use a one to three gallon bucket and a 6” margin trowel for most jobs.
Use a good quality grout, which contains dry latex additives. On most jobs, good quality grout mixed with water is sufficient. Alternately, in areas where added durability or water resistance is needed, you may want to mix grout with a latex grout additive or “milk” as provided for by the manufacturer.
Start the mix with a little liquid in the bottom of the bucket. Add a portion of dry grout to it and stir it a little. Add more liquid a little at a time until you get to the right consistency. The right consistency may vary a bit depending on the type of grout (sanded or un-sanded) or the application (floor, wall, countertop, etc.) Generally, grout should be just loose enough to flow easily into the joint, but stiff enough to stay in place without excess liquid.
Un-sanded grout for a wall should be no thicker than smooth peanut butter and no looser than toothpaste. Sanded floor grout can be a littler looser, but not sloppy or runny.
Run the margin trowel through the grout in the bucket. If it is stiff like a clod of wet dirt, it’s probably too dry. If it slumps too quickly and doesn’t stand up or peak, it’s probably too wet. When mixing, don’t ignore “slaking”. Slaking is a process of thoroughly mixing and then letting the mix stand or rest before remixing. Slaking allows the pigments and additives to completely incorporate in the grout.
After the first mix, the grout will stiffen quite quickly. But with the second stirring the mix will loosen up again. During grouting, stir the mix often to keep it loose, but never add more liquid later to loosen an old mix.

Using a grout float:

With the right mix and a good rubber grout float, the grout should flow deep into the joint.For floors, pour or scoop out a portion of grout from the bucket onto the floor. Floor grout, especially sanded grout, can be fairly loose, but not soupy. Hold the grout float at about a 45-degree angle relative to the floor and sweep across the tile surface at about a 45-degree angle relative to the grout joint grid. This will allow the float to pass across the tiles removing excess grout where it is not needed. It also allows the float to pass across the joints without getting hung up or trapped in the grout crevasse.
As you go, make sure each vacant grout joint is filled completely. Work an area that you can easily reach from one kneeling position, and then move to an adjacent small section. Fill overlapping sections one by one while backing your way out of the room.
For walls or vertical surfaces like tile base, the grout needs to be mixed a little stiffer to stay in place.
In many applications you will be using un-sanded grout for wall work with small 1/16th inch joints. Un-sanded grout on walls needs a little extra push to insure that the grout goes all the way down into the joint. You can start with sweeping motions across the tile surface applying most of the grout. But then go back over each horizontal and vertical joint in the section with the short end of the float to make sure the joint is filled and there are no voids. Start at the bottom of the wall and work in sections to the top. It’s easy to miss spots, especially with un-sanded grout, if you don’t keep yourself at eye level with the work.

Wiping away the excess grout:

Once you have floated-in the grout, you’ll need to consider the wiping process.
Timing is very important in the wiping process.  If grout is mixed properly, it should stay workable in the bucket for a good while. But once it is spread, it will start to cure or dry. As you move from one section to another while applying the grout, you will see the first sections drying. If you wait too long, the wiping process can become very difficult. If you see the grout becoming quite dry and hard while you grout, don’t hesitate to stop grouting and do an initial wipe on those areas. The grout in the bucket will stay workable while you tend to the drying grout.
I like to wipe grout in about three steps. With each wipe, use clean cool water. Always use the large yellow sponges specifically designed for tile work. Wet and clean the sponge completely and then wring it out completely with each wipe. The idea with wiping is to remove excess grout from the areas you don’t want it, and to leave it in the places you do want it. If the sponge is too damp, the excess water will push the materials away from the sponge leaving it on the surface.
The first wipe can be done within 20 or 30 minutes. With this first wipe, concentrate on wiping the excess off the tile surfaces and less emphasis on wiping the joint. Excessive wiping in the joint at this point when the grout is still tender will remove too much of the grout in the joint. As you go, look for voided or low spots indicating joints that didn’t get filled. Keep the grout bucket nearby and fill voids as you see them.
After another 30 minutes or so you can do a second wipe with clean cool water. This time the grout is a little tougher and you can start wiping along the grout joint, which will pull them straight and smooth the top. You shouldn’t need to apply a hard scrubbing action. Just draw the sponge gently in line with the joint a few times to make a neat and smooth grout line. Let the action of the damp sponge do the work.
The technique in the third wipe is important. By this time you should have a fairly clean tile surface and full, straight and smooth grout joints. Usually, however, there is a hazy or chalky residue left behind. Start your third wipe with clean cool water and a barely damp sponge. Now with one side of the sponge, and with only one stroke, pull the sponge toward you across the tiles. Turn the sponge over on the clean side and again with only one stroke, pull the sponge toward you. After only one wipe on each clean side of the sponge, rinse the sponge and wring it out completely. Continue this process over the entire surface. The idea is to make the sponge work to lift as much of the residue as possible. Any re-wiping with a dirty side of the sponge will only reapply the residue.  After an hour or so and using a clean dry towel, lightly polish off the final hazy residue.

What’s the difference between Sanded and
Un-sanded grout?

There are basically two types of grout used that are widely used today. They are referred to as Sanded and Un-sanded.

Sanded grout consists of: 1 part portland cement, 2 parts fine sand, cellulose (to hold the water in the mix), defoamers (to prevent air entrapment during mixing), and polymers (for strength and flexibility).

Un-sanded grout consists of: 1 part portland cement, 2 parts calcium carbonate (used as a filler powder), cellulose, defoamers, and polymers.

Sanded grout should be used when the spacing between tiles is 1/8" or more. It tends to be more durable because of the silica sand that it contains. Most floor jobs will require sanded grout.

Un-sanded grout should be used when the spacing between tiles is 1/16" or less. Because most wall tile will be spaced at 1/16" or less and some wall tiles will have self-spacing edges on them un-sanded grout is the best choice.

Now have a go with that grout repair.  From us guys at the Construction Corner, Keep up the great work!