Porcelain and ceramic tile are both are part of the larger category of tiles that can generally be called ceramic. For modern tile specifications, it is more a case of reverse-naming, whereby manufacturers take tiles that have certain qualities and then assign the ceramic or porcelain titles to them.
Ceramic and porcelain are composed differently and do behave accordingly upon installation, but with only slight differences.The chief difference is that porcelain tile is more impervious than ceramic tile and is thus subject to greater water infiltration.According to the industry group that decides whether a tile is porcelain or ceramic, everything boils down to that one issue: meeting a set of water absorption criteria. Another standards group, this one independent of the tile industry, even pushes the definition further by stating that porcelain is dense, impervious, fine-grained, and smooth, in addition to the same water absorption criteria.
Porcelain has a low water absorption rate.Porcelain tile has a water absorption rate of 0.5 percent or lower as defined by American Society for Testing and Materials (ASTM) section C373. First, fired tile is weighed. Then it is boiled for five hours and let to sit in water for 24 hours. Next, it is weighed again. If the tile weighs less than half of one-percent more as a result of water absorbing into its surface, it is considered porcelain.
Porcelain tile is often extruded; has fewer impurities than ceramic; is often rectified; and often contains more kaolin than ceramic. It is formed of quartz, clay, and feldspar that is fired at temperatures ranging from 1,200 to 1,400 degrees C.But since that also defines many ceramics, again the difference is that porcelain has that 0.5 percent or less water absorption rate.