Homeowners must always apply grout to their tiles while installing them. This grout acts partially as a mortar to help bind the tiles together and partially as a separator that keeps the tiles a specific distance apart so they do not scrape together. While there are different types of grouting materials, grout is generally classified in two types: sanded and unsanded or non-sanded. Homeowners should use the grout that works best with their tile.
There are three basic grout varieties. The first is a Portland cement grout, which is based in a simple cement mixture. The second is an epoxy grout, which hardens into a plastic-like material, and the third is a furan resin grout made of specific chemicals designed to resist acidic wear. Any of these grouts can be either sanded or unsanded, which simply means that a filler sand material is added to the grout, giving it a rougher texture and appearance, or a chalk-like dust is used, making it look like a smooth putty. There is little difference in cost between sanded and unsanded varieties.
The common rule of grout recommends that any time tile joints (the spaces between the tiles) are greater than 1/8 inch wide, they should be filled in with a sanded grout, while any time the joints are less than 1/8 inch wide, a non-sanded grout should be used. Sanded grouts bind more fully in wide spaces and are more durable, so they work best with larger spaces.
The size of the tile joints may not mean much to homeowners looking for a particular type of tile. Basically, ceramic tiles and similar materials have wider grout lines that are usually filled in with sanded grout. Stone tiles like marble and granite have very tight grout lines, and must be filled in with unsanded grout. Another common rule is that the smaller the tiles, the larger the joints, which means small tiles are bonded with sanded grout and larger tiles tend to require non-sanded grout.
Sanded grout is usually a white, gray or light brown shade, which goes better with the lighter tiles it is most often used with. Darker sanded grout options are available, but are more difficult to find. Non-sanded grouts tend to be darker grays and browns, since they must match darker stonework. Again, lighter non-sanded grouts can be found, but they tend to be rarer and used mostly for lighter marble tiles.
Homeowners lay the grout differently depending on what type of grout it is. There is no significant difference between laying sanded and non-sanded grouts, only between different ingredients like epoxies and Portland cement. They must both be measured very carefully to ensure a straight fit, and allowed to cure before the tile is used.