“Saltillo tile is a type of terra-cotta tile that originates in Saltillo, Coahuila, Mexico. Saltillo-type tiles are now manufactured at many places in Mexico, and high-fire “Saltillo look” tiles, many from Italy, compete with the terra-cotta originals.
Saltillo tile vary in colour and shape, but the majority range from in varying hues of reds, oranges and yellows. Saltillo tile is highly porous, and soaks in liquid easily. Unlike most ceramic tile, there is no glaze on the top surface of the tile. It is difficult to install as it absorbs water from the thin-set mortar, grout, grease pencils, etc. Once placed, it stains and scuffs easily if not properly sealed and maintained with a quality sealant. Saltillo is probably a poor choice for outdoor installation in freeze-thaw climates, although is a popular choice in warmer climates. During installation the tiles should be handled carefully to avoid stains that can even occur from body oils on the installer’s hands.
Another method involves soaking the tile, setting the tile then allowing it to dry, sealing the tile, then grouting. This method prevents the grout from sticking to the tile. A penetrating sealant will maintain the natural look of the tile. You should periodically test the seal by putting a few drops of water on the tile in various places. If the water is absorbed, then another coat of sealant should be applied.”