These type of sealers are made from polyurethanes or acrylics. These sealers are designed to sit on the surface of the stone and can be used to change the look or slip resistance of the flooring. These sealers are effective at stopping stains but they tend to wear out very quickly, especially on high-traffic areas. It is important to also note that these sealers are not breathable and are not really effective against salt attack, such asefflorescenceandspalling, so for greater protection we would advise impregnating sealers.
Penetrating sealers use siliconates, fluoro-polymers and siloxanes. Theses sealers are quite similar to topical sealers, but will penetrate the stone a little deeper in order to anchor the sealer to the surface. These sealers will change the slip resistance of a floor, and will offer some protection from surface spills, but just like topical sealers will not last very long at all and will not protect against salt attack, such asefflorescenceand spalling.
Impregnating sealers use silanesor modified silanes. The reason why impregnating sealers are used by professional companies is because Impregnating sealers penetrate deeply into the material, deep enough to repel water or oils from within the material. Some modified silane sealers impregnate deeply enough to protect against salt attack, such asefflorescence,spalling, picture framing and freeze-thaw spalling. Only impregnating sealers will protect against weathering and traffic and will offer a more long term solution for the protection of stone.