One of the most common problems associated with the use of natural stone is that it stains very easily. As previously discussed the removal of a stain can be quite expensive and, sometimes, not even possible. To eliminate or reduce the possibility of staining, it is essential that the stone be properly protected with a good quality impregnator or sealer.
First, an explanation of the terms “impregnator” and “sealer” are in order. An impregnator is a chemical designed to penetrate into the stone and provide a barrier to prevent or repel water, pigment, dye, dirt, and other foreign substances from penetrating into the stone while still allowing vapor to transmit out of the stone or “breathe”. Sealers also provide a protective barrier however, not all sealers allow the stone to breathe. A sealer designated as a “penetrating” sealer is usually designed to function the same as an impregnator while most other topical sealers or “coatings” such as acrylic do not. The use of the term sealer in this document is synonymous with impregnator.
Besides being water or solvent based, impregnators are also classified into two types by function: hydrophobic or oleophobic. Hydrophobic repels only water while oleophobic repels both water and oil. The oleophobic types are solvent based and usually more expensive, but they offer much better protection from a wider variety of stains. In the end, spending a little more up front may save you from a costly stain removal later. All floors should be impregnated as part of the initial maintenance process and re-impregnated every 3-5 years or after refinishing whichever comes first. NOTE: Solvent based impregnators are preferred for hard stone (Granite) high traffic areas and outdoors for its resistance to ultra violet rays from the sun. Enhancing sealers bring out the color in flat stone such as slate, sandstone, limestone, flamed granite, etc.