When we stayed at Darmada (www.darmadabali.com), an inland resort near Sidemen, we were impressed by the decorative floor and wall tiles. Well, as it turns out the owners, an Indonesian-Dutch couple, also own the nearby factory, Sadustile, where these tiles are made so not only did we get to enjoy their beauty we got to see just how they are made.
(See slideshow at end)
Although they look a lot like ceramic tiles they are not, instead they are what are called cement tiles or encaustic cement tiles, a kind of tile made without the firing process that ceramic tiles require.
I know I have seen them many places, particularly in Mexico and in U.S. buildings built during the 20s or before but I just didn’t realize they were a different type of tile. Although they may be one solid color they are commonly decorated in a variety of patterns using many rich colors and because they are hand made they have subtle variability that adds to their richness. In addition they are durable and easy to maintain.
The manufacturing process is likely little changed since its development in France in the 1850s. A mold in the shape of the tile is placed on a smooth surface and the desired pattern made from thin strips of metal is placed in the mold. The tile is made up in three layers, the first will impart the various colors dictated by the pattern. A slurry of white Portland cement, white marble powder and natural mineral color pigments is added to the sections of the pattern to a depth of about one-eighth inch (3-4mm). The color penetrates deeply into the tile unlike most patterned ceramic tiles. A second layer of dry fine sand and normal gray Portland cement is added next followed by the third layer of moist coarse sand and Portland. The mold is leveled off and a die is placed over the cement mixture and a pressure of several hundred pounds per square inch is applied with a hydraulic press. The tile is placed face down on a piece of glass and the mold is released.. At this point the tile is very fragile and must be handled carefully; it is allowed to mature overnight but it will not reach anything like full strength since too little water has been used in the process so far. After a suitable time the tiles are transferred to a water bath where they remain for several days to allow the cement to react and reach full strength. Tiles are trimmed and placed on racks to dry out in preparation for shipment.