There are certain questions we hear time and time again when clients are in the process of deciding on the appropriate floor and/or wall tile for their home. In this issue of “ON THE ROCKS”, we will provide you with the fundamentals you need to understand, in order to make an informed purchasing decision.

1.- Ceramic vs. porcelain

The simple fact is, both porcelain and ceramic tile are basically made of the same materials: quartz sand, red or white clays, talc, feldspar, kaolin, calcite, dolomite. Ceramic is a word derived from the ancient Greek “Keramos”, roughly translated to “of fired clay”. Ceramic tile is molded and fired in kilns.

Ceramic is a softer and less dense material. More suited to walls and low traffic applications. Porcelain tiles are generally pressed and fired at a much higher temperature than ceramic tiles. This process makes porcelain tile more dense, less porous, much harder and less prone to moisture (water absorption less than 0.5%) and stain absorption than ceramic tiles. For these reasons, most porcelain tiles are suitable for both indoor and outdoor applications.

2.- What are the different types of tile available

GLAZED: After the ceramic/porcelain tiles are fired, a thin coat of liquefied glass is applied over the top surface feature in a colored or highly designed surface or the tile can be naturally colored and left unglazed like terra cotta, either in a high gloss or matte finish. The glazing is what makes these tiles so highly moisture and stain resistant. Most porcelain/ceramic tile has either a white or red body coloration underneath the glazed, colored top layer.

THROUGH BODY (TECHNICAL) PORCELAIN: sometimes referred to as unglazed porcelain tiles are produced using colored raw materials that permeate through the entire tile. This results in an uninterrupted color and pattern seen on the surface all the way through the tile body. The surface design is evident in a crosssection of the tile body, providing outstanding abrasion resistance and durability.

3.- Rectified v. natural (edge)

Rectified tile has been mechanically cut or ground down to an exact size (with straight edges). While ceramic and porcelain tiles are heated, they are subject to size variability based on minute differences in firing temperatures and composition. So ordinary tiles that are molded and then fired, but not RECTIFIED, will have slight dimensional differences that may effect how neatly and precisely the tiles can be laid out. What this means as a practical matter is that RECTIFIED tiles can be installed with minimal joint lines on a level (floated) floor rather than the large wide joint lines associated with natural (non RECTIFIED) tiles, that are used to accommodate the slight size variation.

4.- Tile installation options
There are a multitude of choices when it comes to installation options for your tile floor depending on the color and type. An important factor to consider, when choosing a floor pattern is the size of the room. In a smaller room, certain patterns can effectively increase the feeling of space, where as large spaces can create an appetite for more busy and complex pattens. Ultimately, it is a matter of taste. Pictured are some of the most popular tile patterns.

5.- Thinset v. mudset

Tile set by the thinset method is adhered to the substrate with a thin layer of ” thinset” cement. This type of cement is designed to adhere well as a thin layer – typically not greater than 3/16th” thick. While ver minor adjustments in height can be made, this method is not appropriate for adjusting the level or flatness of a surface. Typically tiles installed with thinset, will have wider joint lines (compared to rectified tile or stone).

Thick-Bed or Mud Set installations are based on the traditional method of packing a mortar bed over the surface before installing tiles. The mortar bed may be reinforced with wire and either set over a cleavage membrane (that allows the mortar bed to “float” free of the substrate) or bonded to the substrate; hence the use of terms such as “floating mortar bed” or “bonded mortar bed”.

Ok, so why would you use Thinset v. Mudset???

Well I’m glad you asked! As mentioned earlier, if you want tight joints, RECTIFIED tiles (or stone tile) are what you want. To achieve a narrow joint, the floor will most likely have to be leveled (floated), with a Mud Set.

Usually, when thinset is used, wider open joints are employed to accommodate the size variation of the tile and a floor that is not completely level.

You can often feel this when you walk on a tile floor. Either the floor is perfectly level and you can feel the evenness of the surface, or you feel the peaks and valleys. If you pay attention, you can see the difference: wider open joints for the uneven floor; tight narrow joints for even leveled Mud Set floor. Depending on the results you want to achieve and your budget (Thinset installations are generally less expensive, since they use less setting material and are less labor intensive), a thinset installation may be a suitable option.

Want to know more? Here are some great websites to continue your research:

The Tile Council of North America


World Floor Covering Association


About Home


The Tile Letter


Grandview Research