Terra-cotta tiles are made of a red clay that is hand-formed and fired at low temperatures. The resultant tiles are extremely porous, ranging in colour from light golds to dark browns. There are many ways to seal and protect terra-cotta while enhancing its colour. Its porous nature requires it to be sealed several times to keep maintenance to a minimum. To both seal the terra-cotta and deepen its colour, a mixture of linseed oil can be applied to the surface of the tiles once they have been cleaned.
Mix 1 cup vinegar and 1 gallon warm water. Mop the tiles with this solution to remove dirt or debris that could become trapped in the linseed oil. Let the terra-cotta dry.
Mix equal parts paint thinner and linseed oil in a clean bucket. The paint thinner acts as a vehicle to get the oil into the terra-cotta.
Mop the terra-cotta with the linseed mixture with a fresh mop head. Pay close attention to coverage; the tiles immediately darken after applying the oil. Check for light areas.
Once the terra-cotta is dry, a second application can be made. Depending on how porous the terra-cotta is, several applications may be necessary.