The word Terracotta means “burned earth”. Terracotta tiles are completely natural products: combination of two simple natural elements, clay and fire. The clay is pressed singularly by man’s experienced hands in a mould and fired by master oven attendant to produce tiles that can be used inside and outside any home. Terracotta tile surface is typically irregular and color and texture varies depending on the type of clay and the fired temperature.
Terracotta tiles are predominantly made in one of two ways: machine made (extruded) or hand made. Both methods will service the consumer well as long as the material is properly installed and the client's expectation corresponds to the intended use of the product. The major advantage of extruded terracotta manufactured by machine is that the clay is compressed and trimmed to the proper size, producing a strong, solid finished product. If we compare this to the process of making a snowball, the harder we push the snow together, the more we compress it, the harder and stronger our snowball is. The less we compress it the more likely our snowball is to break apart. The machine compression process allows for less clay to be used during production which can reduce material and shipping costs. The compression and then firing of the material creates a strong and durable tile that should withstand daily wear and tear of most consumers.
A hand made material such as Saltillo tile usually requires much more clay during the production process and is made similarly to the way kids make mud pies. The craftsmen pack the clay into wood or ceramic frames which define the size of each tile. As the size of the tile increases the thickness of material must also increase to maintain the integrity of each tile. An example is a 12" x 12" handmade material may need to be approximately ¾" thick. As the size of the tile increases to a 16" x 16", the thickness of material needs to increase to a minimum of approximately 1" to prevent the tile from crumbling or breaking during the installation process. The added clay required in the hand made process usually increases material and shipping costs.
When a hand made clay tile is fired at high temperature, the heat extracts the moisture from the clay causing several results that must be considered during the selection process. Small pockets of air are in the tile where moisture had been before firing making a very porous product. This porosity means that this type of terracotta is a poor choice for an outside application in a colder climate where freeze/thaw conditions exist. Also, the tiles frequently bow during firing. The larger the tile, the more exaggerated and pronounced the curl will become during the firing process. The added thickness of material and bowing (which increases the absolute thickness) needs to be considered when attempting to match materials to existing floors. Hand made material usually also requires a thicker mortar base during the installation process which can further compound floor thickness challenges. In other words, will the terracotta's and setting material's added thickness allow it to be set next to an existing floor or adjacent to carpet without excessive lippage.
In the end, handmade or extruded terracotta or Saltillo will hold up well if properly installed and I have seen many installations hold up for over 50 years. The key to a successful project is the selection of a quality terracotta or Saltillo, proper substrate preparation, using proper setting materials and methods appropriate for the installation, and completed by a licensed tile contractor familiar with these types of installations.