Travertine is a form of limestone that is used as a popular floor tile. It naturally forms in mineral-rich hot springs. Gas bubbles from the spring become trapped in the stone and give the travertine a pitted surface. This surface is frequently finished using a dust resin or epoxy to give the tile a more polished, finished look. If you decide to use a sealer on it, several options are available.
Travertine and Food
Travertine is very sensitive to food acidity even when sealed and thus it is likely to become etched when exposed to it. For this reason, travertine is not recommended for use on kitchen counter tops. A sealer cannot prevent the etching, but it can make it much less noticeable. Travertine is similar to marble in that it is also sensitive to chemicals and needs to be sealed with care.
Topical sealers sit on the top of the stone and provide a coating that protects the tile from damage. Most topical sealers are water-based and are recommended because they are gentler than harsher chemicals. The purpose of the sealer is to reduce the natural absorbency of the stone so foreign materials such as dirt and liquids will not sink into the stone and will instead remain on the surface until they can be wiped away. They generally provide a shiny, glossy look to the stone.
The difficulty with topical sealers is that the coating damages fairly quickly. To keep the floors in peak condition, the coating must be frequently stripped and then reapplied. Because of the extra work, topical sealers, especially those that are water-based, are generally cheaper than other varieties.
Sealers that are solvent-based can be harsher and wear out the material, so only use a solvent-based tile sealer if it specifically says that it is designed to work with travertine.
Impregnating sealers sink into the tile and protect the stone from within by depositing solid materials into the tile pores to coat the material beneath it. The active ingredient of an impregnating sealer is a resin that can be either naturally occurring or synthetically made. The resin is melted into a solution with either water or a mineral solvent that acts as a delivery device. After the sealer is applied, the water or solvent evaporates and leaves the resin in the stone, hardening to form a protectant that prevents the stone from absorbing other materials. The advantage of impregnating sealers is that they do not need to be stripped before being reapplied and generally do not need to be applied nearly as often as topical sealers. They tend to be more expensive because they last longer.
Always thoroughly clean the tiles of any dust and debris before applying any type of sealer so you don't inadvertently lock the dirt into the floor. Make sure the sealer is applied evenly to prevent color differences in the stone and peeling.
Sealers work differently from each other; some will only repel water while others will propel both oil and water. If you are applying the sealer in an area where grease and oil could come into contact with it (such as a kitchen floor), make sure the sealer repels oil.