Why is grout used

Why is Grout Used in natural stone flooring ?

Why is Grout Used?

This question is asked constantly and is usually with the companion question which is: What is it ? We will take a swing at answering both of these in this post.

We can start with an answer to what it is. Typically, it  is a mixture of Portland cement, water, colorants, and in recent times, admixtures that promote elasticity, curing, workability, etc. We have presented this definition for quick and dirty layman purposes. Rest assured that thousands of words can and have been dedicated to this topic. We will keep it simple.

There are also many types of grout but we will address only three. Here they are:

  • Sanded material  is normally used when the space between tile, stone, terra cotta, or other elements is greater than 1/8 inch. By the way, this “space” is normally referred to as the grout joint.
  • Unsanded material  is used when the joint is less than 1/8 inch.
  • Epoxy grouts come into play when there are special and unusually adverse conditions. For example, commercial kitchens, meat packing facilities, breweries etc.

Now, why is grout used at all? Well, in many stone installations it is barely present because the faces of stone tiles are usually very close to exactly the same size and shape. Now think of this. Ceramic tile and terra cotta, as examples, will usually have facial dimensions that vary. So a joint is used for purposes of alignment. As a crazy example, your cookies go in the oven one size and shape. They come out another size and shape. If you wanted to align all your cookies then you would need a joint and something to fill it with. There you have one reason for grout.

Grout also serves another purpose. Your tile is adhered, in most cases, on the down or back side. When grout is worked into the joints it adds strength to the whole assembly by creating a bond side to side also. More is better here. See more information on how to care for natural stone


A final idea is on color. Once upon a time, your choice was gray, or gray, or gray. Today your choices are vast. In general, the larger decision is between a color of grout that works with the tile color or a grout color that contrasts. In our view, a grout that blends with the field tile is vastly more simple.

We hope we have helped answer Why is Grout Used? Thanks for reading. See more information on www.ardex.com