How to Know if Terra Cotta Tiles Are Glazed
- 1). Examine the color of the tile. The color of unglazed terra cotta varies depending on the clay used to make it and comes in natural tones ranging from white to brown to red. Any other color indicates glazing. This also applies to very bright colors such as a cherry red and to tiles with, for example, border color designs that differ from the rest of the tile.
- 2). Pour a few drops of water on a tile. Glazed terra cotta tiles or tiles that have been coated with a sealing compound will not absorb the water; it will bead up.
- 3). Look at the back of a terra cotta tile if you have one that has not been installed. Glazes are usually applied to only one side of a tile. If the color on the reverse side differs from the color on the front and lacks a sheen, then the tile is glazed.
- 4). Examine the edge of one tile. If a ceramic tile is glazed, only the color of the surface is altered. If the inside of the tile is different in color, then the tile is glazed. If you have loose tiles, you can be certain of the interior color by breaking one. However, this test is most likely impossible to apply to terra cotta tile that is already installed. In this case, if the methods described in Steps 1 and 2 don't help, your only recourse may be to ask a tile installation professional to make a determination.
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