Applying Grout Like a Pro

by Murray Anderson

Grouting is the finishing step in installing a tile wall or floor. Grout actually serves a dual function, a practical one of filling in the spaces between the tiles and providing stability to the tiles, plus, an aesthetic function since using grout in different colors, textures or tints can create totally different appearances with exactly the same tiles.

A little bit about grout

By far, the most common tile grout is made using Portland cement, although specialty grouts manufactured from materials such as epoxy are available for specialized applications.
Two main types of grout are used in homes, sanded or unsanded/non sanded. Sanded grout has a heavier texture and is used when the seams between tiles are more than 1/16th of an inch (about the thickness of a penny), while non sanded grout works better when the tile seams are closer together.

Applying grout

Grout is applied after the tiles have been laid down and the mortar bed/mastic has been allowed to set up for a day or so. The process is fairly straight forward but it does require you get down on your knees, so a good pair of knee pads is a necessity.
Before applying any grout you need to take some time to remove the spacers that were used between the tiles to position them properly. You also need to see if any mastic or mortar has been left on the surface or in the cracks between the tiles. A utility knife should be able to pop the spacers out of the seams as well as scrape any left over adhesive form the tile surfaces.
You also want to check that all your tiles are firmly attached. If one or two are loose it's much easier to pick them up and apply more adhesive now, before you start grouting.
You want to apply tile grout in small areas (approximately 4 square feet) at a time. Keep your work area small and manageable, because grout starts 'setting up' as soon as it's been mixed and if you try to cover too large an area some will have set up before you can smooth the grout seams.
You can buy premixed grout (and not worry about mixing it at all) or make your own following the manufacturers directions on the package.
Before you actually begin grouting, use a spray bottle to give the tiles a light misting of water. This will prevent the tiles from drawing moisture out of the grout, making it set up too quickly and potentially crack over time.
Apply the grout with a rubber tile float held at a 45° angle to the seams. Angling the float this way will push the grout all the way down into the cracks between the tiles. After getting the grout into the seams,use the grout float to 'cut off' any grout remaining on the surface, so the grout lines are even with the surface of the tiles.
Once you've installed the grout in the work area, it's time to 'work' the grout. Working the grout involves cleaning the tile surfaces while at the same time compacting the grout in the tile seams. Use a clean, damp sponge again held diagonally to the tile seams, to remove any grout left on the surface. Pushing down firmly, (but not hard enough to actually remove grout from the cracks of the tiles) will compact the grout in the seams at the same time. Be sure to rinse out your sponge and change the water often so the tile surfaces are being cleaned with clean water.
Finish grouting and working the grout in one section, before moving onto the next sections and repeating the process.
Allow grout to set up at least overnight then clean off any remaining grout haze with an old towel or a piece of cheesecloth.