Tile installations date back to 2500 BC – yes, BC. People discovered that if you take natural clay and mix with minerals, heat them to extreme temperatures then allow them to cool, you end up with the world’s first honey-do task – maybe. Tile has proven to be the most versatile decorative finish that humans have engineered, in fact silica tile is used to protect the space shuttle as it re-enters the Earth’s atmosphere. This monograph will offer an abridged but accurate description of a two tile types that are used in retail environments, ceramic and porcelain.
Though the terms are often used interchangeably, they are in fact different. To add to this confusion, Ceramic is also the term used to define the entire set of inorganic materials prepared by heating and cooling, which includes ceramic tiles and porcelain tiles. For sake of clarity, when the term ceramic is used to reference the tile type (subset), it will not be underlined.
Constituents of Ceramic & and Porcelain tile types-
Much like concrete, tiles are a mixture of materials found in the Earth’s crust.
Clay + sand + feldspar + minerals + water comprise the bulk of the mixture for both ceramic and porcelain.
Differences between Porcelain tile and Ceramic tiles-
Porcelain tile contains a higher ratio of feldspar and lower ratio of clay than ceramic. Feldspar (pictured) is a silicate mineral which is both hard and can withstand high temperatures. Another difference between ceramic and porcelain are the pressures used to prepare them. Porcelain tile types are made using higher pressures – resulting in a harder surface. As a general rule, porcelain tiles are harder than ceramic. In addition, the porosity of the porcelain tile is less, providing better stain resistance than ceramics. Porcelain tiles are ideal for exterior applications.
To glaze or not to glaze-
Both tile types come in glazed and unglazed finishes. Glazing is an added step in the manufacturing process which involves the coating of the unbaked tile with a glass like film. To do this, extreme temperatures are used, and the glaze penetrates into the bulk of the unbaked tile (bisque) – sealing and encapsulating the tile, rendering it relatively impervious. The higher the luster of a tile, the greater the stain resistance. Although a performance benefit, glazed tile can be an end use disadvantage as it is slippery and will highlight an uneven floor or wall surface.
Mortar and grout-
Mortar is the term used to describe the cementitious compound in which the tiles are set. Once the tiles are set in the mortar, the mortar cures and mechanically locks the tiles in place. The width between each tile is the grout line. In America, these are spaced between 1/16” – 3/4”. Grout selection is made based on the desired width, as well as environment. For small widths (less than 1/8”), a non sanded grout should be used. Between 1/8” – 1/4”, a finely sanded grout works best and coarser grouts for widths greater that 1/4”. In harsh environments, epoxy resins can be added to the grout to provide sealed and chemically resistant spacing.